@article{yilmaz_jordan_2024, title={EFFECT OF THE PLANTING PATTERN ON TOTAL OIL QUALITY AND FATTY ACID COMPOSITIONS IN PEANUT (Arachis hypogaea L.) CULTIVARS}, volume={36}, ISSN={["2521-9693"]}, DOI={10.51372/bioagro362.8}, abstractNote={Research in the Eastern Mediterranean Transition Region of Türkiye has demonstrated that plant density impact yield of peanut (Arachis hypogaea L.) cultivars differentially. It is suspected that interactions of plant density and cultivar could also impact oil quality and fatty acid composition when grown in this region. This topic has not been addressed in the country; therefore, the objective of this research was to determine if plant density can affect those variables. The study was conducted in 2020 and 2021 in the zone of Osmaniye to determine total oil content of kernels, and contents of oleic acid, palmitic acid, arachidonic acid, linoleic acid, stearic acid, and lignoceric acid, as well as iodine value and oleic/linoleic ratio for the cultivars Halisbey, Rigel, Aysehanım, NC 7, and Masal. Plant response was in most instances different regardless of plant populations made up of a single row planting pattern with rows spaced 70 cm apart (95.000 plants ha-1) compared with a twin row planting pattern with rows spaced 20 cm apart on 90 cm centers with an intra-row distance of 15 cm (148.000 plants ha-1). It is concluded that no differences in oil quality and fatty acid composition were noted when comparing cultivars established at various combinations of planting pattern and plant population, but there were notable differences among the cultivars.}, number={2}, journal={BIOAGRO}, author={Yilmaz, Mustafa and Jordan, David L.}, year={2024}, pages={203–210} } @article{seidu_abudulai_dzomeku_mahama_nboyine_appaw_akromah_arthur_bolfrey-arku_mochiah_et al._2024, title={Evaluation of Production and Pest Management Practices in Peanut (Arachis hypogaea) in Ghana}, volume={14}, ISSN={["2073-4395"]}, DOI={10.3390/agronomy14050972}, abstractNote={The economic return for peanut (Arachis hypogaea L.) in Ghana is often low due to limitations in the availability of inputs or their adoption, which are needed to optimize yield. Six experiments were conducted in Ghana in 2020 and 2021 to determine the impact of planting date, cultivar, fertilization, pest management practices, and harvest date on peanut yield, financial return, and pest reaction. A wide range of interactions among these treatment factors were often observed for infestations of aphids (Aphis gossypii Glover); groundnut rosette disease (Umbravirus: Tombusviridaee); millipedes (Peridontopyge spp.); white grubs (Schyzonicha spp.); wireworms (Conoderus spp.); termites (Microtermes and Odontotermes spp.); canopy defoliation as a result of early leaf spot disease caused by Passalora arachidicola (Hori) and late leaf spot caused by Nothopassalora personata (Berk. and M. A. Curtis); and the scarification and boring of pods caused by arthropod feeding. Pod yield and economic return increased for the cultivar Chitaochi and Sarinut 2 when fertilizer was applied and when fertilizer was applied at early, mid-, and late planting dates. Pod yield and economic return increased when a combination of locally derived potassium soaps was used for aphid suppression and one additional hand weeding was used in the improved pest management practice compared with the traditional practice without these inputs. Pearson correlations for yield and economic return were negatively correlated for all pests and damage caused by pests. The results from these experiments can be used by farmers and their advisors to develop production packages for peanut production in Ghana.}, number={5}, journal={AGRONOMY-BASEL}, author={Seidu, Ahmed and Abudulai, Mumuni and Dzomeku, Israel K. and Mahama, Georgie Y. and Nboyine, Jerry A. and Appaw, William and Akromah, Richard and Arthur, Stephen and Bolfrey-Arku, Grace and Mochiah, M. Brandford and et al.}, year={2024}, month={May} } @article{jordan_anco_balota_brandenburg_2024, title={Farmer insights on harvesting peanut: A survey from the Virginia-Carolina region of the United States}, volume={10}, ISSN={["2374-3832"]}, DOI={10.1002/cft2.20262}, abstractNote={Plain Language Summary Peanut harvest is a two‐step process that requires digging pods and inverting vines and threshing after pods and vines have dried for an adequate amount time. Weather patterns, including temperature and soil moisture, can affect the pod maturation process. Additionally, inclement weather, soil moisture conditions, farm logistics, balance of equipment and acreage, plant health and disease incidence, and equipment setting and operation can affect harvest efficiency and yield. A survey of 166 farmers in North Carolina, South Carolina, and Virginia, representing 25% of acreage, was administered to determine their perceptions of challenges they face at harvest and how they address those challenges. The majority of growers indicated that they would dig pods and invert vines prior to a storm. Peanut maturity was as important as soil conditions and concerns over tropical weather when deciding when to dig peanut.}, number={1}, journal={CROP FORAGE & TURFGRASS MANAGEMENT}, author={Jordan, David L. and Anco, Dan and Balota, Maria and Brandenburg, Rick L.}, year={2024}, month={Jun} } @article{foote_jordan_gorny_dunne_lux_ahumada_shew_brandenburg_ye_2024, title={Influence of Cropping Sequence and Tillage System on Plant-Parasitic Nematodes and Peanut (Arachis hypogaea) Response to Fluopyram Applied at Planting}, volume={14}, ISSN={["2073-4395"]}, DOI={10.3390/agronomy14040875}, abstractNote={Crop sequence and tillage can affect the yield of peanut (Arachis hypogaea L.) and other crops. Research was conducted from 2006 through 2022 to determine the response of peanut to previous crop sequences including corn (Zea mays L.) and cotton (Gossypium hirsutum L.) planted in continuous conventional tillage (e.g., disking, field cultivating, and bedding with in-row sub-soiling) or strip tillage (e.g., tilling a 45 cm section on rows spaced 91 cm apart using fluted coulters, rolling baskets, and in-row sub-soiling). In 2013, 2019, and 2022, the entire test area was planted with peanut. In 2019 and 2022, peanut was planted without or with fluopyram applied in the seed furrow at planting. Decreasing the number of years between peanut planting resulted in lower peanut yields compared with fewer years of peanut planting in the rotation sequence. Continuous conventional tillage and strip tillage resulted in similar peanut yields at one location, while the yield was lower at a second location when peanut was planted in continuous strip tillage. Fluopyram did not affect peanut yield regardless of previous crop rotation sequence, the number of years separating peanut plantings, or the tillage system. However, minor differences in the populations of plant-parasitic nematodes in soil were noted when comparing fluopyram treatment. The results from these experiments indicate that while fluopyram can reduce the populations of some plant-parasitic nematodes in soil, the magnitude of reduction does not translate into increases in peanut yield.}, number={4}, journal={AGRONOMY-BASEL}, author={Foote, Ethan and Jordan, David and Gorny, Adrienne and Dunne, Jeffrey and Lux, Leann and Ahumada, Daisy and Shew, Barbara and Brandenburg, Rick and Ye, Weimin}, year={2024}, month={Apr} } @article{cahoon_jordan_tranel_york_riggins_seagroves_inman_everman_leon_2024, title={Influence of gender and glyphosate resistance on Palmer amaranth growth and interference with cotton}, volume={10}, ISSN={["2374-3832"]}, url={https://doi.org/10.1002/cft2.20272}, DOI={10.1002/cft2.20272}, abstractNote={Abstract Management of herbicide‐resistant weeds can be improved by understanding the biology of resistant biotypes. While the majority of research has focused on female plants and seed production of Palmer amaranth ( Amaranthus palmeri S. Watson) that are resistant to glyphosate, growth of male plants that are resistant to this herbicide has not been studied in detail. Additionally, interference of male versus female Palmer amaranth plants on cotton ( Gossypium hirsutum ) yield has not been reported. Plant height and biomass of male and female plants from a mixed population of glyphosate‐resistant (GR) and glyphosate‐susceptible (GS) plants was studied in North Carolina when grown season‐long with cotton. Palmer amaranth height was less for GR male plants compared with GS males and both GR and GS females. Biomass of Palmer amaranth female plants was twice that of male plants irrespective of glyphosate resistance. Cotton yield was affected similarly by Palmer amaranth regardless of either gender or glyphosate resistance status. The implications of shorter GR male plants on pollen dispersal and ramifications on management of glyphosate resistance are not known. Results from these trials did not address implications of the height of male plants on fitness of GR resistance. Nonetheless, the finding that GR male plants were shorter in the field than GS male plants warrants a new look at this topic. Similar reductions for cotton yield in presence of both GR and GS biotypes and genders suggest that current yield loss assessments and management decisions do not need to consider these variables in Palmer amaranth populations.}, number={1}, journal={CROP FORAGE & TURFGRASS MANAGEMENT}, author={Cahoon, Charles W. and Jordan, David L. and Tranel, Patrick J. and York, Alan C. and Riggins, Chance and Seagroves, Richard and Inman, Matthew and Everman, Wesley and Leon, Ramon}, year={2024}, month={Jun} } @article{mulvaney_iboyi_balkcom_jordan_zurweller_jani_2024, title={Nitrogen credits after peanut (Arachis hypogaea L.)}, ISSN={["1435-0645"]}, DOI={10.1002/agj2.21669}, journal={AGRONOMY JOURNAL}, author={Mulvaney, Michael J. and Iboyi, Joseph E. and Balkcom, Kipling S. and Jordan, David and Zurweller, Brendan and Jani, Arun}, year={2024}, month={Sep} } @article{ippolito_jennings_monks_chaudhari_jordan_moore_blankenship_2024, title={Response of stevia to reduced-risk synthetic and nonsynthetic herbicides applied post-transplant}, volume={38}, ISSN={["1550-2740"]}, DOI={10.1017/wet.2024.20}, abstractNote={Abstract Greenhouse trials were conducted to determine the response of stevia to reduced-risk synthetic and nonsynthetic herbicides applied over-the-top post-transplant. In addition, field trials were conducted with stevia grown in a polyethylene mulch production system to determine crop response and weed control in planting holes to reduced-risk synthetic and nonsynthetic herbicides applied post-transplant directed. Treatments included caprylic acid plus capric acid, clove oil plus cinnamon oil, d-limonene, acetic acid (200 grain), citric acid, pelargonic acid, eugenol, ammonium nonanoate, and ammoniated soap of fatty acids. Stevia yield (dry aboveground biomass) in the greenhouse was reduced by all herbicide treatments. Citric acid and clove oil plus cinnamon oil were the least injurious, reducing yield by 16% to 20%, respectively. In field studies, d-limonene, pelargonic acid, ammonium nonanoate, and ammoniated soap of fatty acids controlled Palmer amaranth (>90% 1 wk after treatment (WAT). In field studies caprylic acid plus capric acid, pelargonic acid, and ammonium nonanoate caused >30% injury to stevia plants at 2 WAT, and d-limonene, citric acid, acetic acid, and ammoniated soap of fatty acids caused 18% to 25% injury 2 WAT. Clove oil plus cinnamon oil and eugenol caused <10% injury. Despite being injurious, herbicides applied in the field did not reduce yield compared to the nontreated check. Based upon yield data, these herbicides have potential for use in stevia; however, these products could delay harvest if applied to established stevia. In particular, clove oil plus cinnamon oil has potential for use for early-season weed management for organic production systems. The application of clove oil plus cinnamon oil over-the-top resulted in <10% injury 28 d after treatment (DAT) in the greenhouse and 3% injury 6 WAT postemergence-directed in the field. In addition, this treatment provided 95% control of Palmer amaranth 4 WAT.}, journal={WEED TECHNOLOGY}, author={Ippolito, Stephen J. and Jennings, Katherine M. and Monks, David W. and Chaudhari, Sushila and Jordan, David and Moore, Levi D. and Blankenship, Colton D.}, year={2024}, month={May} } @article{jordan_anco_balota_langston_lux_shew_brandenburg_2024, title={Survey of herbicide and fungicide use in peanut in North Carolina and Virginia in the United States}, volume={10}, ISSN={["2374-3832"]}, DOI={10.1002/cft2.20263}, abstractNote={Plain Language Summary Diseases and weeds can reduce yield of peanut ( Arachis hypogaea L.) if effective control measures including fungicides and herbicides are not used. A survey of 76 farmers in North Carolina and Virginia at Cooperative Extension Service meetings was completed relative to fungicide and herbicide use in 2021. Eighty‐two percent of farmers made between three and five herbicide applications, while 68% of farmers made between four and five fungicide applications. 2,4‐DB was the herbicide applied most frequently. The fungicide chlorothalonil was applied the most often. Pydiflumetofen was applied by 61% of farmers. Results from this survey can be used to inform regulatory agencies on pesticide use patterns by defining the relative importance of individual or groups of pesticides currently used to suppress pests and prevent or mitigate associated economic losses.}, number={1}, journal={CROP FORAGE & TURFGRASS MANAGEMENT}, author={Jordan, David L. and Anco, Dan and Balota, Maria and Langston, David and Lux, Leann and Shew, Barbara and Brandenburg, Rick L.}, year={2024}, month={Jun} } @article{ethridge_chandra_locke_everman_jordan_owen_leon_2023, title={Changes in the herbicide sensitivity and competitive ability of Abutilon theophrasti over 28 years: Implications for hormesis and weed evolution}, volume={79}, ISSN={1526-498X 1526-4998}, url={http://dx.doi.org/10.1002/ps.7604}, DOI={10.1002/ps.7604}, abstractNote={AbstractBACKGROUNDThe potential of weed species to respond to selection forces affecting the evolution of weedy traits such as competitive ability is poorly understood. This research characterized evolutionary growth changes in a single Abutilon theophrasti Medik. population comparing multiple generations collected from 1988 to 2016. A competition study was performed to understand changes in competitive ability, and a herbicide dose–response study was carried out to assess changes in sensitivity to acetolactate synthase‐inhibiting herbicides and glyphosate over time.RESULTSWhen grown in monoculture, A. theophrasti biomass production per plant increased steadily across year‐lines while leaf number decreased. In replacement experiments, A. theophrasti plants from newer year‐lines were more competitive and produced more biomass and leaf area than the oldest year‐line. No clear differences in sensitivity to imazamox were observed among year‐lines. However, starting in 1995, this A. theophrasti population exhibited a progressive increase in growth in response to a sublethal dose of glyphosate (52 g a.e. ha−1), with the 2009 and 2016 year‐lines having more than 50% higher biomass than the nontreated control.CONCLUSIONThis study demonstrates that weeds can rapidly evolve increased competitive ability. Furthermore, the results indicate the possibility of changes in glyphosate hormesis over time. These results highlight the importance of the role that rapid (i.e., subdecadal) evolution of growth traits might have on the sustainability of weed management strategies. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.}, number={10}, journal={Pest Management Science}, publisher={Wiley}, author={Ethridge, Sandra R. and Chandra, Saket and Locke, Anna M. and Everman, Wesley J. and Jordan, David L. and Owen, Micheal D.K. and Leon, Ramon G.}, year={2023}, month={Jun}, pages={4048–4056} } @article{moore_jennings_monks_boyette_leon_jordan_ippolito_blankenship_chang_2023, title={Evaluation of electrical and mechanical Palmer amaranth (Amaranthus palmeri) management in cucumber, peanut, and sweetpotato}, volume={1}, ISSN={["1550-2740"]}, url={https://doi.org/10.1017/wet.2023.1}, DOI={10.1017/wet.2023.1}, abstractNote={AbstractField studies were conducted to assess the efficacy of physical weed management of Palmer amaranth management in cucumber, peanut, and sweetpotato. Treatments were arranged in a 3 × 4 factorial in which the first factor included a treatment method of electrical, mechanical, or hand-roguing Palmer amaranth control and the second factor consisted of treatments applied when Palmer amaranth was approximately 0.3, 0.6, 0.9, or 1.2 m above the crop canopy. Four wk after treatment (WAT), the electrical applications controlled Palmer amaranth at least 27 percentage points more than the mechanical applications when applied at the 0.3- and 0.6-m timings. At the 0.9- and 1.2-m application timings 4 WAT, electrical and mechanical applications controlled Palmer amaranth by at most 87%. Though hand removal generally resulted in the greatest peanut pod count and total sweetpotato yield, mechanical and electrical control resulted in similar yield to the hand-rogued plots, depending on the treatment timing. With additional research to provide insight into the optimal applications, there is potential for electrical control and mechanical control to be used as alternatives to hand removal. Additional studies were conducted to determine the effects of electrical treatments on Palmer amaranth seed production and viability. Treatments consisted of electricity applied to Palmer amaranth at first visible inflorescence, 2 wk after first visible inflorescence (WAI) or 4 WAI. Treatments at varying reproductive maturities did not reduce the seed production immediately after treatment. However, after treatment, plants primarily died and ceased maturation, reducing seed production assessed at 4 WAI by 93% and 70% when treated at 0 and 2 WAI, respectively. Treatments did not have a negative effect on germination or seedling length.}, journal={WEED TECHNOLOGY}, author={Moore, Levi D. D. and Jennings, Katherine M. M. and Monks, David W. W. and Boyette, Michael D. D. and Leon, Ramon G. G. and Jordan, David L. L. and Ippolito, Stephen J. J. and Blankenship, Colton D. D. and Chang, Patrick}, year={2023}, month={Jan} } @article{jelliffe_bravo-ureta_jordan_dankyi_appaw_mochiah_2023, title={Exploring mitigating factors for aflatoxin awareness and incidence among smallholder groundnut farmers in Sub-Saharan Africa}, volume={16}, ISSN={["1875-0796"]}, DOI={10.1163/18750796-20232833}, abstractNote={Abstract This study considers the association between agricultural extension, aflatoxin, and good management practices among smallholder groundnut farmers in sub-Saharan Africa. The first part examines extension and self-reported knowledge and perceptions of aflatoxin for three countries. This is done using pooled survey data (n = 1388) collected from 2014 to 2016, beginning with Uganda (n = 480) in 2014, Ghana (n = 537) in 2015, and Mozambique (n = 335) in 2016. Results from probit regressions suggest that aflatoxin knowledge and perceptions are related to village extension services, household head education, farm size, groundnut production area, and experience with aflatoxins. To build upon these findings, additional information on aflatoxin levels and good management practices for a sub-sample of the 2015 Ghana survey (n = 134) is analysed. Negative binomial regression estimates indicate significantly lower aflatoxin levels for households that (1) follow good management practices and (2) are in receipt of village extension services, with the lowest average aflatoxin level from the combination of (1) and (2). These findings underscore the role of extension in combating the incidence of aflatoxin in groundnut value chains. In this way, extension is associated with greater knowledge and perceptions, as well as lower levels of aflatoxin, that can be further reduced with good management practices.}, number={4}, journal={WORLD MYCOTOXIN JOURNAL}, author={Jelliffe, J. and Bravo-Ureta, B. and Jordan, D. and Dankyi, A. and Appaw, W. and Mochiah, M.}, year={2023}, month={Dec}, pages={359–371} } @article{ren_gibson_gage_matthews_owen_jordan_shaw_weller_wilson_young_2023, title={Exploring the effect of region on diversity and composition of weed seedbanks in herbicide-resistant crop systems in the United States}, ISSN={["1526-4998"]}, DOI={10.1002/ps.7875}, abstractNote={AbstractBACKGROUNDSoil seedbanks have been recognized as one of the crucial components of agricultural ecosystems. However, studies on the shift in structure and biodiversity of soil seedbanks in herbicide‐resistant crop systems are limited, and a functional trait perspective of the soil seedbank is often overlooked.RESULTSA 6 years experiment was conducted to investigate the roles of region, crop system, and weed management strategy on species richness, functional trait diversity, and composition of the weed seedbank. Species richness was different across the interaction of region and crop system, while functional trait diversity only showed difference across regions. Species and functional trait compositions were affected by the interaction of region and crop system. Specifically, the compositional difference among crop systems was mainly determined by the significant heterogeneity of group dispersion.CONCLUSIONGrowers and practitioners should consider weed functional traits in developing lasting agricultural management strategies. Long‐term weed research should draw attention to the impact of transgenic crop systems and specific management tactics on weed dispersal, functional composition, and resistance evolution of weed species in such agroecosystems. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.}, journal={PEST MANAGEMENT SCIENCE}, author={Ren, Zhe and Gibson, David J. and Gage, Karla L. and Matthews, Joseph L. and Owen, Micheal D. K. and Jordan, David L. and Shaw, David R. and Weller, Stephen C. and Wilson, Robert G. and Young, Bryan G.}, year={2023}, month={Nov} } @article{mahoney_jordan_leon_oreja_roma-burgos_2023, title={Fecundity and maternal effects on Palmer amaranth height following season-long interference in corn, cotton, and peanut}, volume={9}, ISSN={["2374-3832"]}, url={https://doi.org/10.1002/cft2.20233}, DOI={10.1002/cft2.20233}, abstractNote={AbstractPalmer amaranth (Amaranthus palmeri Watson) is one of the most difficult‐to‐control weeds in several economically important crops in the United States. Growth characteristics of Palmer amaranth can be affected by the cropping system. Research was conducted in North Carolina in 2019 to determine height and seed production of Palmer amaranth grown season long in the presence of corn (Zea mays L.), cotton (Gossypium hirsutum L.), and peanut (Arachis hypogaea L.). Research was also conducted to determine transgenerational effects due to interference from these crops. Palmer amaranth produced more seed when grown with cotton (17 times greater) and peanut (12 times greater) compared with corn; no difference was noted between cotton and peanut. Palmer amaranth height in the field at physiological maturity was similar in corn (80 inches) and cotton (77 inches) and taller in height than peanut (63 inches). When progeny from plants in the field were grown in the greenhouse in the absence of crop interference, differences in the height of progeny and height of the mother plant in the presence of crop interference were ranked similarly with respect to crop. Palmer amaranth height in the presence of corn and cotton was similar (57 and 58 inches, respectively) and it exceeded height when the weed was grown with peanut (51 inches). These results demonstrate transgenerational effects due to previous crop (e.g., corn, cotton, and peanut) for Palmer amaranth.}, number={2}, journal={CROP FORAGE & TURFGRASS MANAGEMENT}, author={Mahoney, Denis J. and Jordan, David L. and Leon, Ramon and Oreja, Fernando H. and Roma-Burgos, Nilda}, year={2023}, month={Dec} } @article{tilley_jordan_vann_gatiboni_heiniger_stevens_ambrose_2023, title={Influence of planting pattern on corn response to sub-surface drip irrigation}, volume={9}, ISSN={["2374-3832"]}, DOI={10.1002/cft2.20247}, abstractNote={Core Ideas Under a moderate to high pricing structure, a subsurface irrigation system can pay for itself when growing corn. A twin‐row planter does not increase yield or increase financial returns regardless of irrigation system. Financial returns will likely be higher under sub‐surface irrigation when compared with dryland corn production. }, number={2}, journal={CROP FORAGE & TURFGRASS MANAGEMENT}, author={Tilley, M. Scott and Jordan, David L. and Vann, Rachel A. and Gatiboni, Luke and Heiniger, Ronnie W. and Stevens, Brian and Ambrose, Derek}, year={2023}, month={Dec} } @article{oreja_hare_jordan_leon_2023, title={Previous crop and herbicide timing application effects on weed population growth rate}, volume={9}, ISSN={["2374-3832"]}, url={https://doi.org/10.1002/cft2.20232}, DOI={10.1002/cft2.20232}, abstractNote={AbstractA well‐designed crop rotation can create an unstable environment that disrupts weed population growth rates. In combination with effective herbicide programs, growers may maintain weed populations at levels below competitive and economic thresholds. The objectives of the present study were to evaluate how the preceding rotational crop determines the response of weed populations to in‐season postemergence herbicide programs and the weed population density of the following crop season. The first‐year crop treatments were corn (Zea mays L.), cotton (Gossypium hirsutum L.), peanut (Arachis hypogaea L.), grain sorghum [Sorghum bicolor (L.) Moench.], and soybean [Glycine max (L.) Merr.]. In the second year, all plots were planted with cotton, and herbicide treatments were single applications 2 or 6 weeks after planting (WAP), two sequential applications 2 and 4 or 4 and 6 WAP, three sequential applications 2, 4, and 6 WAP, and a weedy control without herbicides was included. In the absence of herbicides, corn had the lowest population growth rates for broadleaf weeds (λ = 0.8) while peanut and grain sorghum had the highest (λ = 1.7 and 1.3, respectively). The results indicated that herbicide applications focused exclusively on preventing yield loss may not be sufficient to ensure weed population reductions. Thus, the observed population growth rates (λ = 2 for grassy weeds and λ = 1.26 for broadleaved weeds) indicated that weed issues would continue increasing, despite meeting yield goals. Considering population growth rates when assessing weed management strategies is key to determining the sustainability of the crop production operation.}, number={2}, journal={CROP FORAGE & TURFGRASS MANAGEMENT}, author={Oreja, Fernando H. and Hare, Andrew T. and Jordan, David L. and Leon, Ramon G.}, year={2023}, month={Dec} } @article{ethridge_chandra_everman_jordan_locke_owen_leon_2023, title={Rapid evolution of competitive ability in giant foxtail (Setaria faberi) over 34 years}, volume={71}, ISSN={0043-1745 1550-2759}, url={http://dx.doi.org/10.1017/wsc.2023.1}, DOI={10.1017/wsc.2023.1}, abstractNote={AbstractCompetition between genotypes within a plant population can result in the displacement of the least competitive by more competitive genotypes. Although evolutionary processes in plants may occur over thousands and millions of years, it has been suggested that changes in key fitness traits could occur in as little as decades, with herbicide resistance being a common example. However, the rapid evolution of complex traits has not been proven in weeds. We hypothesized that changes in weed growth and competitive ability can occur in just a few years because of selection in agroecosystems. Seed of multiple generations of a single natural population of the grassy weed giant foxtail (Setaria faberi Herrm.) were collected during 34 yr (i.e., 1983 to 2017). Using a “resurrection” approach, we characterized life-history traits of the different year-lines under noncompetitive and competitive conditions. Replacement-series experiments comparing the growth of the oldest year-line (1983) versus newer year-lines (1991, 1996, 1998, 2009, and 2017) showed that plant competitive ability decreased and then increased progressively in accordance with oscillating selection. The adaptations in competitive ability were reflected in dynamic changes in leaf area and biomass when plants were in competition. The onset of increased competitive ability coincided with the introduction of herbicide-resistant crops in the landscape in 1996. We also conducted a genome-wide association study and identified four loci that were associated with increased competitive ability over time, confirming that this trait changed in response to directional selection. Putative transcription factors and cell wall–associated enzymes were linked to those loci. This is the first study providing direct in situ evidence of rapid directional evolution of competitive ability in a plant species. The results suggest that agricultural systems can exert enough pressure to cause evolutionary adaptations of complex life-history traits, potentially increasing weediness and invasiveness.}, number={1}, journal={Weed Science}, publisher={Cambridge University Press (CUP)}, author={Ethridge, Sandra R. and Chandra, Saket and Everman, Wesley J. and Jordan, David L. and Locke, Anna M. and Owen, Micheal D. K. and Leon, Ramon G.}, year={2023}, month={Jan}, pages={59–68} } @article{jordan_shew_brandenburg_anco_balota_2023, title={Summary of tillage practices in peanut in the Virginia-Carolina region of the United States}, volume={9}, ISSN={["2374-3832"]}, DOI={10.1002/cft2.20222}, abstractNote={Core Ideas Deep tillage in the form of moldboard plow decreased in peanut in North Carolina from 1998 to 2018. Reduced tillage was adopted by more peanut farmers in South Carolina and Virginia than in North Carolina. More farmers strip‐tilled peanut across all states rather than no till. }, number={1}, journal={CROP FORAGE & TURFGRASS MANAGEMENT}, author={Jordan, David L. and Shew, Barbara B. and Brandenburg, Rick L. and Anco, Dan and Balota, Maria}, year={2023}, month={Jun} } @article{sims_mitchem_jennings_monks_jordan_hoffmann_2023, title={Tolerance of muscadine grape to 2,4-D choline postemergence-directed}, volume={2}, ISSN={["1550-2740"]}, DOI={10.1017/wet.2023.8}, abstractNote={AbstractField studies were conducted in commercial muscadine vineyards in western North Carolina in 2018 and eastern North Carolina in 2019, 2020, and 2021 to determine tolerance of younger (< 9 yr) and older (≥ 9 yr) bearing muscadine grapevines to 2,4-D directed beneath the crop postemergence (POST). Treatments included 2,4-D choline at 0, 0.53, 1.06, 1.60, and 2.13 kg ae ha−1 applied as a single treatment in May or June (spring) at immediate pre-bloom, and sequential treatments at 0.53 followed by (fb) 0.53, 1.06 fb 1.06, 1.6 fb 1.6, or 2.13 fb 2.13 kg ha−1. The first sequential treatment was applied in spring fb another application of the same amount in July (summer) at pre-veraison. No differences in injury on muscadine grapevines were observed from 2,4-D treatments. Differences among treatments were not observed for yield of younger vines. However, for older vines, a difference due to 2,4-D rate was observed in 2018, when yield was higher when 2,4-D was applied at 1.6 kg ha−1 compared with nontreated grapevines, and when 2,4-D was applied at 0.53 and 2.13 kg ha−1. A rate-by-timing interaction was observed in 2019 when yield was lower from 0.53 kg ha−1 2,4-D summer application compared with all other summer treatments but similar to the nontreated. However, no biological pattern was observed from either of these differences. No differences among treatments were observed for fruit pH, titratable acidity, or soluble solid content of either younger or older vines.}, journal={WEED TECHNOLOGY}, author={Sims, Kira C. and Mitchem, Wayne E. and Jennings, Katherine M. and Monks, David W. and Jordan, David L. and Hoffmann, Mark}, year={2023}, month={Feb} } @article{ethridge_grieger_locke_everman_jordan_leon_2023, title={Views of RNAi approaches for weed management in turfgrass systems}, volume={7}, ISSN={["1550-2759"]}, url={https://doi.org/10.1017/wsc.2023.37}, DOI={10.1017/wsc.2023.37}, abstractNote={AbstractPublic concern regarding the use of herbicides in urban areas (e.g., golf courses, parks, lawns) is increasing. Thus, there is a need for alternative methods for weed control that are safe for the public, effective against weeds, and yet selective to turfgrass and other desirable species. New molecular tools such as ribonucleic acid interference (RNAi) have the potential to meet all those requirements, but before these technologies can be implemented, it is critical to understand the perceptions of key stakeholders to facilitate adoption as well as regulatory processes. With this in mind, turfgrass system managers, such as golf course superintendents and lawn care providers, were surveyed to gain insight into the perception and potential adoption of RNAi technology for weed management. Based on survey results, turfgrass managers believe that cost of weed management and time spent managing weeds are the main challenges faced in their fields. When considering new weed management tools, survey respondents were most concerned about cost, efficacy, and efficiency of a new product. Survey respondents were also optimistic toward RNAi for weed management and would either use this technology in their own fields or be willing to conduct research to develop RNAi herbicides. Although respondents believed that the general public would have some concerns about this technology, they did not believe this to be the most important factor for them when choosing new weed management tools. The need for new herbicides to balance weed control challenges and public demands is a central factor for turfgrass managers’ willingness to use RNAi-based weed control in turfgrass systems. They believe their clientele will be accepting of RNAi tools, although further research is needed to investigate how a wider range of stakeholders perceive RNAi tools for turfgrass management more broadly.}, journal={WEED SCIENCE}, author={Ethridge, Sandra R. and Grieger, Khara and Locke, Anna M. and Everman, Wesley J. and Jordan, David L. and Leon, Ramon G.}, year={2023}, month={Jul} } @article{jordan_buol_brandenburg_shew_wilkerson_lassiter_dunne_gorny_washburn_hoisington_et al._2022, title={A Risk Tool and Production Log Created using Microsoft Excel to Manage Pests in Peanut (Arachis hypogaea)}, volume={13}, ISSN={["2155-7470"]}, DOI={10.1093/jipm/pmac006}, abstractNote={Abstract Peanut (Arachis hypogaea L.) growers and their advisors need to address a wide range of biotic and abiotic stresses to maximize yield and financial return. Mitigating risk to yield and financial investment requires knowledge of interactions among pests and strategies to manage pests, including chemical inputs, crop rotation, cultivar selection, field pest history, planting pattern and population, planting date, and tillage systems. Using Microsoft Excel, a comprehensive peanut risk tool was developed to assist growers and advisors in identifying and selecting production strategies to minimize risk to yield based on empirical data and practical experience while providing cost estimates of production practices. Initially, the risk tool was developed for North Carolina (USA) peanut production. However, the current platform is designed to facilitate the development of similar tools for other USA peanut regions, peanut production systems in other countries, and with the capability to develop risk tools for other crops. This article discusses components of the risk management tool developed for North Carolina peanut production. Benefits of the risk tool to practitioners, extension services, genetics and breeding programs, and formal classroom instruction will be discussed. One goal of this paper is to provide an example of how the Microsoft Excel framework used for peanut in North Carolina can be used for peanut in other regions of the USA and other countries.}, number={1}, journal={JOURNAL OF INTEGRATED PEST MANAGEMENT}, author={Jordan, David L. and Buol, Greg S. and Brandenburg, Rick L. and Shew, Barbara B. and Wilkerson, Gail G. and Lassiter, Bridget R. and Dunne, Jeff and Gorny, Adrienne and Washburn, Derek and Hoisington, David and et al.}, year={2022}, month={Jan} } @article{ethridge_locke_everman_jordan_leon_2022, title={Crop physiological considerations for combining variable-density planting to optimize seed costs and weed suppression}, volume={70}, ISSN={0043-1745 1550-2759}, url={http://dx.doi.org/10.1017/wsc.2022.62}, DOI={10.1017/wsc.2022.62}, abstractNote={AbstractHigh crop densities are valuable to increase weed suppression, but growers might be reluctant to implement this practice due to increased seed cost. Because it is also possible to lower planting densities in areas with no or low weed interference risk, the area allocated to each planting density must be optimized considering seed cost and productivity per plant. In this study, the growth and yield of maize (Zea mays L.), cotton (Gossypium hirsutum L.), and soybean [Glycine max (L.) Merr.] were characterized in response to low planting densities and arrangements. The results were used to develop a bioeconomic model to optimize the area devoted to high- and low-density plantings to increase weed suppression without increasing seed cost. Physiological differences seen in each crop varied with the densities tested; however, maize was the only crop that had differences in yield (per area) between densities. When a model to optimize low and high planting densities was used, maize and cotton showed the most plasticity in yield per planted seed (g seed−1) and area of low density to compensate for high-density area unit. Maize grown at 75% planting density compared with the high-planting density (200%) increased yield (g seed−1) by 229%, return by 43%, and profit by 79% while decreasing the low-density area needed to compensate for high-density area. Cotton planted at 25% planting density compared with the 200% planting density increased yield (g seed−1) by 1,099%, return by 46%, and profit by 62% while decreasing the low-density area needed to compensate for high-density area. In contrast, the high morphological plasticity of soybean did not translate into changes in area optimization, as soybean maintained return, profit, and a 1:1 ratio for area compensation. This optimization model could allow for the use of variable planting at large scales to increase weed suppression while minimizing costs to producers.}, number={6}, journal={Weed Science}, publisher={Cambridge University Press (CUP)}, author={Ethridge, Sandra R. and Locke, Anna M. and Everman, Wesley J. and Jordan, David L. and Leon, Ramon G.}, year={2022}, month={Nov}, pages={687–697} } @article{jordan_wells_washburn_barnes_corbett_2022, title={Crop yield and estimated financial return from subsurface drip irrigation for corn, cotton, and peanut over the life of the system}, volume={8}, ISSN={["2374-3832"]}, DOI={10.1002/cft2.20167}, abstractNote={Core Ideas Subsurface drip irrigation increased corn, cotton, and peanut yield in some (not all) years. Financial returns over the irrigation system's life did not differ from dryland production. Subsurface irrigation supports economic viability some years but not over the system's life. }, number={2}, journal={CROP FORAGE & TURFGRASS MANAGEMENT}, author={Jordan, David and Wells, Randy and Washburn, Derek and Barnes, Steve and Corbett, Tommy}, year={2022} } @article{basinger_hestir_jennings_monks_everman_jordan_2022, title={Detection of Palmer amaranth (Amaranthus palmeri) and large crabgrass (Digitaria sanguinalis) with in situ hyperspectral remote sensing. I. Effects of weed density and soybean presence}, volume={70}, ISSN={["1550-2759"]}, url={https://doi.org/10.1017/wsc.2021.81}, DOI={10.1017/wsc.2021.81}, abstractNote={AbstractThe utilization of remote sensing in agriculture has great potential to change the methods of field scouting for weeds. Previous remote sensing research has been focused on the ability to detect and differentiate between species. However, these studies have not addressed weed density variability throughout a field. Furthermore, the impact of changing phenology of crops and weeds within and between growing seasons has not been investigated. To address these research gaps, field studies were conducted in 2016 and 2017 at the Horticultural Crops Research Station near Clinton, NC. Two problematic weed species, Palmer amaranth (Amaranthus palmeri S. Watson) and large crabgrass [Digitaria sanguinalis (L.) Scop.], were planted at four densities in soybean [Glycine max (L.) Merr.]. Additionally, these weed densities were grown in the presence and absence of the crop to determine the influence of crop presence on the detection and discrimination of weed species and density. Hyperspectral data were collected over various phenological time points in each year. Differentiation between plant species and weed density was not consistent across cropping systems, phenology, or season. Weed species were distinguishable across more spectra when no soybean was present. In 2016, weed species were not distinguishable, while in 2017, differentiation occurred at 4 wk after planting (WAP) and 15 WAP when weeds were present with soybean. When soybean was not present, differentiation occurred only at 5 WAP in 2016 and at 3 WAP through 15 WAP in 2017. Differentiation between weed densities did occur in both years with and without soybean present, but weed density could be differentiated across more spectra when soybean was not present. This study demonstrates that weed and crop reflectance is dynamic throughout the season and that spectral reflectance can be affected by weed species and density.}, number={2}, journal={WEED SCIENCE}, author={Basinger, Nicholas T. and Hestir, Erin L. and Jennings, Katherine M. and Monks, David W. and Everman, Wesley J. and Jordan, David L.}, year={2022}, month={Mar}, pages={198–212} } @article{yilmaz_jordan_2022, title={EFFECT OF PLANT DENSITY ON YIELD AND QUALITY OF PEANUT (Arachis hypogaea L.) CULTIVARS}, volume={27}, ISSN={["1301-1111"]}, DOI={10.17557/tjfc.1148572}, abstractNote={Plant density can have a major impact on peanut (Arachis hypogaea L.) yield. Information is limited in the Eastern Mediterranean Transition Region of Turkiye on growth, development, and yield of peanut cultivars based on plant density. To address this limitation, the cultivars Aysehanim, Rigel, Halisbey, Masal, and NC 7 were established in a single row planting pattern consisting of rows spaced 70 cm apart with an inter-row plant distance of 15 cm (95.000 plants ha-1) versus a twin row planting pattern consisting of rows spaced 20 cm apart on 90 cm centers with an intra-row distance of 15 cm (148.000 plants ha-1). The interaction of cultivar × plant density was significant for most variables. Irrespective of cultivar, establishing a plant population of 148.000 plants ha-1 in the twin row planting pattern resulted in greater pod yield than the single row planting pattern with a plant density of 95.000 plants ha-1. Pod yield was similar for Rigel, Masal, and NC 7 in the twin row planting pattern and exceeded that of Aysehanim and Halisbey. Conversely, yield of Rigel and Halisbey was similar in the single row pattern and exceeded yield of Aysehanim and NC 7.}, number={2}, journal={TURKISH JOURNAL OF FIELD CROPS}, author={Yilmaz, Mustafa and Jordan, David Lindley}, year={2022}, pages={217–223} } @article{oreja_inman_jordan_vann_jennings_leon_2022, title={Effect of cotton herbicide programs on weed population trajectories and frequency of glyphosate-resistant Palmer amaranth (Amaranthus palmeri)}, volume={7}, ISSN={["1550-2759"]}, url={https://doi.org/10.1017/wsc.2022.41}, DOI={10.1017/wsc.2022.41}, abstractNote={AbstractThe adoption of dicamba-resistant cotton (Gossypium hirsutum L.) cultivars allows using dicamba to reduce weed populations across growing seasons. However, the overuse of this tool risks selecting new herbicide-resistant biotypes. The objectives of this research were to determine the population trajectories of several weed species and track the frequency of glyphosate-resistant (GR) Palmer amaranth (Amaranthus palmeri S. Watson) over 8 yr in dicamba-resistant cotton. An experiment was established in North Carolina in 2011, and during the first 4 yr, different herbicide programs were applied. These programs included postemergence applications of glyphosate, alone or with dicamba, with or without residual herbicides. During the last 4 yr, all programs received glyphosate plus dicamba. Biennial rotations of postemergence applications of glyphosate only and glyphosate plus dicamba postemergence with and without preemergence herbicides were also included. Sequential applications of glyphosate plus dicamba were applied to the entire test area for the final 4 yr of the study. No herbicide program was entirely successful in controlling the weed community. Weed population trajectories were different according to species and herbicide program, creating all possible outcomes; some increased, others decreased, and others remained stable. Density of resistant A. palmeri increased during the first 4 yr with glyphosate-only programs (up to 11,739 plants m−2) and decreased a 96% during the final 4 yr, when glyphosate plus dicamba was implemented. This species had a strong influence on population levels of other weed species in the community. Goosegrass [Eleusine indica (L.) Gaertn.] was not affected by A. palmeri population levels and even increased its density in some herbicide programs, indicating that not only herbicide resistance but also reproductive rates and competitive dynamics are critical for determining weed population trajectories under intensive herbicide-based control programs. Frequency of glyphosate resistance reached a maximum of 62% after 4 yr, and those levels were maintained until the end of the experiment.}, journal={WEED SCIENCE}, publisher={Cambridge University Press (CUP)}, author={Oreja, Fernando H. and Inman, Matthew D. and Jordan, David L. and Vann, Matthew and Jennings, Katherine M. and Leon, Ramon G.}, year={2022}, month={Jul} } @article{smith_jennings_monks_jordan_reberg-horton_schwarz_2022, title={Evaluation of Sweetpotato Cultivars with Varying Canopy Architectures in Conventional and a Reduced-tillage Rye Production System}, volume={32}, ISSN={["1943-7714"]}, DOI={10.21273/HORTTECH04912.21}, number={2}, journal={HORTTECHNOLOGY}, author={Smith, Stephen C. and Jennings, Katherine M. and Monks, David W. and Jordan, David L. and Reberg-Horton, S. Chris and Schwarz, Michael R.}, year={2022}, month={Apr}, pages={158–163} } @article{clapp_vann_cahoon_jordan_fisher_inman_2022, title={Evaluations of S-Metolachlor in flue-cured tobacco weed management programs}, volume={2}, ISSN={["1435-0645"]}, url={https://doi.org/10.1002/agj2.20984}, DOI={10.1002/agj2.20984}, abstractNote={AbstractEffective weed control is critical to growth and development of flue‐cured tobacco; however, current herbicide options are limited in commercial production. Field experiments were conducted from 2017 to 2018 to evaluate S‐metolachlor for use in flue‐cured tobacco weed management programs. Treatments included 10 herbicide programs: pretransplanted incorporated (PTI) applications of S‐metolachlor (1.07 kg a.i. ha–1) alone or in various combinations with sulfentrazone (0.18 kg a.i. ha–1), clomazone (0.84 kg a.i. ha–1), and pendimethalin (0.79 kg a.i. ha–1). S‐metolachlor and pendimethalin were also applied posttransplanting directed to row middles (POST‐DIR) following PTI applications of sulfentrazone + clomazone. A single posttransplanting over‐the‐top (POST‐OT) application of S‐metolachlor and a non‐treated control were included for comparison. The inclusion of S‐metolachlor in PTI herbicide programs did not improve weed control beyond the combination of sulfentrazone + clomazone. However, weed control after final harvest was improved by 8%, when S‐metolachlor was applied POST‐DIR. S‐metolachlor applied POST‐OT caused injury to tobacco plants (12%), although symptoms were transient with less than 2% visual injury 6 wk after transplanting. Due to increased weed control through harvest and the low injury potential, our results suggest that POST‐DIR applications of S‐metolachlor are the best fit for flue‐cured tobacco production when used in conjunction with recommended PTI herbicide programs.}, journal={AGRONOMY JOURNAL}, author={Clapp, Andrew M. and Vann, Matthew C. and Cahoon, Charles W. and Jordan, David L. and Fisher, Loren R. and Inman, Matt D.}, year={2022}, month={Feb} } @article{jordan_buol_brandenburg_reisig_nboyine_abudulai_oteng-frimpong_mochiah_asibuo_arthur_et al._2022, title={Examples of Risk Tools for Pests in Peanut (Arachis hypogaea) Developed for Five Countries Using Microsoft Excel}, volume={13}, ISSN={["2155-7470"]}, url={https://doi.org/10.1093/jipm/pmac017}, DOI={10.1093/jipm/pmac017}, abstractNote={Abstract Suppressing pest populations below economically-damaging levels is an important element of sustainable peanut (Arachis hypogaea L.) production. Peanut farmers and their advisors often approach pest management with similar goals regardless of where they are located. Anticipating pest outbreaks using field history and monitoring pest populations are fundamental to protecting yield and financial investment. Microsoft Excel was used to develop individual risk indices for pests, a composite assessment of risk, and costs of risk mitigation practices for peanut in Argentina, Ghana, India, Malawi, and North Carolina (NC) in the United States (US). Depending on pests and resources available to manage pests, risk tools vary considerably, especially in the context of other crops that are grown in sequence with peanut, cultivars, and chemical inputs. In Argentina, India, and the US where more tools (e.g., mechanization and pesticides) are available, risk indices for a wide array of economically important pests were developed with the assumption that reducing risk to those pests likely will impact peanut yield in a positive manner. In Ghana and Malawi where fewer management tools are available, risks to yield and aflatoxin contamination are presented without risk indices for individual pests. The Microsoft Excel platform can be updated as new and additional information on effectiveness of management practices becomes apparent. Tools can be developed using this platform that are appropriate for their geography, environment, cropping systems, and pest complexes and management inputs that are available. In this article we present examples for the risk tool for each country.}, number={1}, journal={JOURNAL OF INTEGRATED PEST MANAGEMENT}, author={Jordan, David L. and Buol, Greg S. and Brandenburg, Rick L. and Reisig, Dominic and Nboyine, Jerry and Abudulai, Mumuni and Oteng-Frimpong, Richard and Mochiah, Moses Brandford and Asibuo, James Y. and Arthur, Stephen and et al.}, editor={Taylor, SallyEditor}, year={2022}, month={Jan} } @article{vann_johnson_jordan_fisher_edmisten_2022, title={Flue-cured tobacco response to sublethal rates of glufosinate}, volume={8}, ISSN={["2374-3832"]}, url={https://doi.org/10.1002/cft2.20141}, DOI={10.1002/cft2.20141}, abstractNote={AbstractGlufosinate is a broad‐spectrum, contact herbicide that is currently applied to genetically engineered row crops that tolerate exposure to the compound. Flue‐cured tobacco (Nicotiana tabacum L.) is susceptible to glufosinate, yet it is commonly grown in close proximity to tolerant crops in North Carolina. The impact of glufosinate drift on flue‐cured tobacco is not known. Research was conducted in North Carolina to test the effects of sublethal rates of glufosinate (0.270, 0.135, 0.067, 0.034, 0.017 lb a.i. acre–1) on flue‐cured tobacco injury, yield, visual quality, financial value, and leaf chemistry. Simulated drift was imposed approximately 5 wk after transplanting. Visual injury increased with exposure rate and ranged from 15 to 83% and from 10 to 83% 1 and 2 wk after treatment, respectively. Cured leaf yield was reduced by 45% at the highest sublethal exposure rate and exhibited a linear decline of 47 lb acre–1 for every 0.01 lb glufosinate acre–1. Visual quality and per acre financial value were not affected by glufosinate, most likely due to the loss of necrotic tissue and late‐season plant growth compensation. Residues of glufosinate in green and cured leaves were likewise not detected. Producers and commercial applicators should exercise caution when applying glufosinate around flue‐cured tobacco because of the injury and yield loss that can result from physical spray drift, as well as the inability to sell tobacco that has been exposed to a pesticide that is not labeled for application.}, number={1}, journal={CROP FORAGE & TURFGRASS MANAGEMENT}, publisher={Wiley}, author={Vann, Matthew and Johnson, Virginia Alice and Jordan, David and Fisher, Loren and Edmisten, Keith}, year={2022} } @article{cahoon_jordan_tranel_york_riggins_seagroves_inman_everman_leon_2022, title={In-field assessment of EPSPS amplification on fitness cost in mixed glyphosate-resistant and glyphosate-sensitive populations of Palmer amaranth (Amaranthus palmeri)}, volume={10}, ISSN={["1550-2759"]}, url={https://doi.org/10.1017/wsc.2022.60}, DOI={10.1017/wsc.2022.60}, abstractNote={AbstractComparing fitness of herbicide-resistant and herbicide-susceptible weed biotypes is important for managing herbicide resistance. Previous research suggests there is little to no fitness penalty from amplification of the 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) gene (a mechanism of glyphosate resistance) in Palmer amaranth (Amaranthus palmeri S. Watson) in controlled studies in the greenhouse or growth chamber. A field study was conducted in North Carolina at three locations naturally infested with A. palmeri to determine vegetative, reproductive, and germination fitness of plants with and without EPSPS amplification grown season-long with cotton (Gossypium hirsutum L.). Seed number was not correlated with EPSPS copy number. However, when plants were binned into two groups, those having an EPSPS copy number ≥2 (relative to reference genes) and those having an EPSPS copy number <2, plant fresh weight and seed number were 1.4 and 1.6 times greater, respectively, for plants with fewer than 2 EPSPS copies. Amaranthus palmeri height and seed germination, and yield of cotton, did not differ when comparing the two binned groups. These data suggest that A. palmeri plants with EPSPS amplification are relatively less fit in the absence of glyphosate, but this reduced fitness does not translate into differences in interference with cotton.}, journal={WEED SCIENCE}, author={Cahoon, Charles W. and Jordan, David L. and Tranel, Patrick J. and York, Alan C. and Riggins, Chance and Seagroves, Richard and Inman, Matthew and Everman, Wesley and Leon, Ramon}, year={2022}, month={Oct} } @article{oreja_inman_jordan_bardhan_leon_2022, title={Modeling weed community diversity based on species population density dynamics and herbicide use intensity}, volume={138}, ISSN={["1873-7331"]}, DOI={10.1016/j.eja.2022.126533}, abstractNote={Herbicide programs change weed population density as well as weed community composition. The repeated use of a given program can result in a weed community that progressively becomes more difficult to manage or could lose its ability to provide ecosystem services. Simulation of those changes using stochastic models considering population dynamics of multiple species makes it possible to identify a priori potential community changes that might result from the use of a given herbicide program. The objectives of this work were to model the population dynamics of weed species under different herbicide programs and how those dynamics change weed community diversity over time. Weed population dynamics were stochastically modeled along ten years using population growth rate (lambda) for each species under different herbicide programs. Lambda values were obtained from an eight-year long, field experiment, and these were used to parameterize the stochastic ranges for the model for each weed species. Population trajectories were modeled for each individual species over ten years and the results were used to estimate richness, diversity, and evenness for each herbicide use scenario. The repeated use of glyphosate alone had a minimal effect on richness, but it caused a strong reduction in weed diversity and evenness. Programs with more mechanisms of action and the use of both preemergence and postemergence herbicides were slightly more likely to suffer the loss of weed species than programs with single or just a few herbicides. Conversely, the former had a higher probability of maintaining weed diversity and evenness than the latter. According to simulations, losses in weed community diversity are reversible, especially when highly competitive species were eradicated allowing other species with lower lambda to increase their populations. However, the eradication of species with low reproductive rates reduced diversity and evenness. The effects of herbicide programs on the weed community lasted for several years even after those programs were modified indicating that seed banks play a major buffering role in the rate of change of weed community composition. Thus, frequent changes in management interrupting the repeated use of specific weed control programs, even under high herbicide intensity use (i.e., number of applications and mechanisms of action), can help maintain weed diversity in agroecosystems.}, journal={EUROPEAN JOURNAL OF AGRONOMY}, author={Oreja, Fernando H. and Inman, Matthew D. and Jordan, David L. and Bardhan, Deepayan and Leon, Ramon G.}, year={2022}, month={Aug} } @article{jordan_hare_wells_2022, title={Peanut response to a commercial blend of nitrogen, phosphorus, potassium, and fulvic acid}, volume={8}, ISSN={["2374-3832"]}, DOI={10.1002/cft2.20180}, abstractNote={Core Ideas A commercial blend of nitrogen, phosphorus, potassium, and fulvic acid did not affect peanut yield. Lack of response to the foliar product was consistent across diverse environments. A commercial blend of nitrogen, phosphorus, potassium, and fulvic acid is not recommended. }, number={2}, journal={CROP FORAGE & TURFGRASS MANAGEMENT}, author={Jordan, David L. and Hare, Andrew T. and Wells, Randy}, year={2022} } @article{ethridge_locke_everman_jordan_leon_2022, title={Response of Maize, Cotton, and Soybean to Increased Crop Density in Heterogeneous Planting Arrangements}, volume={12}, ISSN={2073-4395}, url={http://dx.doi.org/10.3390/agronomy12051238}, DOI={10.3390/agronomy12051238}, abstractNote={The reduction of row spacing and increase of crop population density are important tools for maximizing crop yield. For this strategy to be effective, the crop population should not create intraspecific crop competition that penalizes yield. Thus, planting arrangements that increase light interception throughout the canopy without increasing row spacing might be needed to maintain yield. In this study, heterogeneous planting arrangements on evenly spaced rows were analyzed for maize (Zea mays L.), cotton (Gossypium hirsutum L.), and soybean (Glycine max (L.) Merr.). Each crop had four planting arrangements: (1) normal density in all rows, considered the control, (2) doubled density in all rows, (3) a sequential arrangement of normal and tripled densities (each in every other row; NTNT), and (4) normal-tripled-tripled-normal (NTTN). Maize and cotton did not exhibit changes in growth and architecture when comparing uniform and variable planting arrangements. Soybeans were more adaptable and increased biomass production by 44% to 45% in variable arrangements. None of the crops showed differences in yield due to planting arrangement, so the use of rows with different densities might not be needed when using high densities to maximize yield.}, number={5}, journal={Agronomy}, publisher={MDPI AG}, author={Ethridge, Sandra R. and Locke, Anna M. and Everman, Wesley J. and Jordan, David L. and Leon, Ramon G.}, year={2022}, month={May}, pages={1238} } @article{daramola_johnson_jordan_chahal_devkota_2022, title={Spray water quality and herbicide performance: a review}, ISSN={["1550-2740"]}, DOI={10.1017/wet.2022.97}, abstractNote={AbstractWater is the primary carrier for herbicide applications. Spray water qualities such as pH, hardness, temperature, or turbidity can influence herbicide performance and may need to be amended for optimum weed control. Water quality factors can affect herbicide activity by reducing solubility, enhancing degradation in the spray tank, or forming herbicide-salt complexes with mineral cations, thereby reducing the absorption, translocation, and subsequent weed control. The available literature suggests that the effect of water quality varies with herbicide chemistry and weed species. The efficacy of weak-acid herbicides such as glyphosate, glufosinate, clethodim, sethoxydim, bentazon, and 2,4-D is improved with acidic water pH; however, the efficacy of sulfonylurea herbicides is negatively impacted. Hard-water antagonism is more prevalent with weak-acid herbicides, and trivalent cations are the most problematic. Spray solution temperature between 18 C and 44 C is optimum for some weak-acid herbicides; however, their efficacy can be reduced at relatively low (5 C) or high (56 C) water temperature. The effect of water turbidity is severe on cationic herbicides such as paraquat and diquat, and herbicides with low soil mobility such as glyphosate. Although adjuvants are recommended to overcome the negative effect of spray water hardness or pH, the response has been inconsistent with the herbicide chemistry and weed species. Moreover, information on the effect of spray water quality on various herbicide chemistries, weed species, and adjuvants is limited; therefore, it is difficult to develop guidelines for improving weed control efficacy. Further research is needed to determine the effect of spray water factors and develop specific recommendations for improving herbicide efficacy on problematic weed species.}, journal={WEED TECHNOLOGY}, author={Daramola, Olumide S. S. and Johnson, William G. G. and Jordan, David L. L. and Chahal, Gurinderbir S. S. and Devkota, Pratap}, year={2022}, month={Dec} } @article{smith_jennings_monks_jordan_reberg-horton_schwarz_2022, title={Sweetpotato tolerance and Palmer amaranth control with indaziflam}, volume={3}, ISSN={["1550-2740"]}, url={https://doi.org/10.1017/wet.2022.13}, DOI={10.1017/wet.2022.13}, abstractNote={AbstractField studies were conducted in North Carolina in 2018 and 2019 to determine sweetpotato tolerance to indaziflam and its effectiveness in controlling Palmer amaranth in sweetpotato. Treatments included indaziflam pre-transplant; 7 d after transplanting (DATr) or 14 DATr at 29, 44, 58, or 73 g ai ha−1; and checks (weedy and weed-free). Indaziflam applied postemergence caused transient foliar injury to sweetpotato. Indaziflam pretransplant caused less injury to sweetpotato than other application timings regardless of rate. Palmer amaranth control was greatest when indaziflam was applied pretransplant or 7 DATr. In a weed-free environment, sweetpotato marketable yield decreased as indaziflam application was delayed. No differences in storage root length to width ratio were observed.}, journal={WEED TECHNOLOGY}, author={Smith, Stephen C. and Jennings, Katherine M. and Monks, David W. and Jordan, David L. and Reberg-Horton, S. Chris and Schwarz, Michael R.}, year={2022}, month={Mar} } @article{sims_jennings_monks_jordan_hoffmann_mitchem_2022, title={Tolerance of plasticulture strawberry to 2,4-D choline applied to row middles}, volume={4}, ISSN={["1550-2740"]}, DOI={10.1017/wet.2022.27}, abstractNote={AbstractField studies in strawberry grown on polyethylene-mulched raised beds were conducted from 2018 to 2019 and 2019 to 2020 in Clayton, NC, to determine ‘Camarosa’ and ‘Chandler’ strawberry tolerance to 2,4-D directed to the row middle between beds. Treatments included 2,4-D at 0, 0.53, 1.06, 1.60, and 2.13 kg ae ha−1 applied alone and sequential treatments (0.53 followed by [fb] 0.53 or 1.06 fb 1.06 kg ae ha−1). Initial treatments were applied in winter (December 2018 or January 2020) during vegetative growth, and sequential applications were applied in spring (April 2019 or March 2020) during reproductive growth. No differences among treatments were observed for visual foliage injury, strawberry crop canopy, fruit yield, and fruit quality (pH, titratable acidity, and soluble solid content).}, journal={WEED TECHNOLOGY}, author={Sims, Kira C. and Jennings, Katherine M. and Monks, David W. and Jordan, David L. and Hoffmann, Mark and Mitchem, Wayne E.}, year={2022}, month={Apr} } @article{sims_jennings_monks_mitchem_jordan_hoffmann_2022, title={Tolerance of southern highbush blueberry to 2,4-D choline postemergence-directed}, volume={4}, ISSN={["1550-2740"]}, url={https://doi.org/10.1017/wet.2022.33}, DOI={10.1017/wet.2022.33}, abstractNote={AbstractField studies were conducted on southern highbush blueberry in Elizabethtown and Rocky Point, NC, in 2019, 2020, and 2021 to determine tolerance to 2,4-D choline as a postemergence-directed application. In separate trials for younger and older bearing blueberry bushes, both 2,4-D choline rates and application timing were evaluated. Treatments included 2,4-D choline at 0, 0.53, 1.06, 1.60, and 2.13 kg ae ha–1 applied alone in winter during dormancy, and sequential treatments at 0.53 kg ae ha–1 followed by (fb) 0.53, 1.06 fb 1.06, 1.6 fb 1.6, or 2.13 fb 2.13 kg ae ha–1. The first application of the sequential treatments was applied in winter followed by another application in spring during early green fruit. Injury to blueberry from 2,4-D choline treatments was not observed for either maturity stage, and fruit yield was not affected by any of the treatments. Differences among treatments were not observed for fruit soluble solid content (SSC) in older bushes, or for fruit pH, SSC, and titratable acidity (TA) in younger bushes. In older bushes, fruit pH and TA had rate-by-timing interactions, and TA had a farm-year interaction with differences at Rocky Point in 2019 and Elizabethtown in 2020, but biologically no pattern was observed from the treatments.}, journal={WEED TECHNOLOGY}, author={Sims, Kira C. and Jennings, Katherine M. and Monks, David W. and Mitchem, Wayne E. and Jordan, David L. and Hoffmann, Mark}, year={2022}, month={Apr} } @article{gross_vann_woodley_jordan_2022, title={Winter crop effect on soybean production in the Southeast United States}, volume={114}, ISSN={["1435-0645"]}, url={https://doi.org/10.1002/agj2.20950}, DOI={10.1002/agj2.20950}, abstractNote={AbstractVarious winter crops can be produced before soybean [Glycine max (L.) Merr] in the Southeast United States, however the effect of these winter crops on soybean productivity and the optimum maturity group to use following various winter crops remains unknown. This experiment was conducted in five environments across North Carolina in 2019 and 2020 to understand the effect of winter crop and soybean maturity group (MG) on soybean productivity. Winter crops investigated included cereal rye (Secale cereale L.) as cover crop, cereal rye–crimson clover (Trifolium incarnatum L.) as cover crop mixture, May fallow, wheat (Triticum aestivum L.) for grain, rapeseed (Brassica napus L.) for grain, and June fallow. Three soybean cultivars (MGs III, V, and VII) were evaluated following each winter crop. Data collected were cover crop/residue biomass, winter crop grain yields, soybean stand, soil moisture, soil temperature, soybean chlorophyll content, and soybean yield. Across environments, winter crop did not affect soybean yield despite differences in soybean stand, soil moisture, soil temperature, and soybean chlorophyll content following various winter crops. The results indicate that across the environments evaluated in this experiment, factors such as soybean stand, soil moisture, or N availability were not limiting factors for soybean productivity and that soybean yield response is relatively insensitive to previous crops. Across winter crops, greater yields typically were achieved with a MGs V and VII cultivar than with a MG III cultivar. Results from this experiment demonstrate that the insensitivity of soybean yield to the previous crop allows for flexibility incorporating soybean into rotations and that regardless of the previous winter crop, yield is typically optimized with a MG V cultivar or later when standard management practices are employed.}, number={1}, journal={AGRONOMY JOURNAL}, publisher={Wiley}, author={Gross, MaKayla R. and Vann, Rachel Atwell and Woodley, Alex L. and Jordan, David}, year={2022}, month={Jan} } @article{tilley_jordan_heiniger_vann_crozier_gatiboni_2021, title={A survey of twin-row cropping systems in North Carolina}, volume={7}, ISSN={["2374-3832"]}, DOI={10.1002/cft2.20099}, abstractNote={AbstractTwin‐row (TR) cropping systems have maintained a presence in North Carolina (NC) for more than 30 years. Introduced as an alternative to the single‐row (SR) configuration, it is hypothesized individual plants arranged 7‐ to 9‐inches apart see a decrease in plant‐to‐plant competition. However, the success of TR remains elusive. Only a handful of farmers across NC have been able to increase yield through the implementation of TR. As higher yields are achieved in research using SR, the use of TR is becoming less attractive to growers looking to modernize. In order to understand future trends, two surveys were administered across the state of NC with the following objectives: (a) identify standard production practices used such as row spacing, TR spacing, starter fertilizer placement, and layby application methods, (b) evaluate grower testimonies concerning observed plant stress under diverse environmental conditions, and (c) identify the successes and limitations observed with TR production. Of the 461 farmers surveyed in the general survey, 42% stated they are planting on narrow (30 inch or less) SR with 58% still planting on 36‐inch or greater row spacing. Within the 58%, 148 farmers stated they are considering a transition from wide (>30 inches) to narrow row systems. One hundred and twenty farmers said they would remain on wide SR. In time, 74% of growers will potentially be planting on narrow rows. Twenty‐eight TR farmers (6%) were identified. Two of the 28 twin‐row growers stated they would be reverting back to single‐row production.}, number={1}, journal={CROP FORAGE & TURFGRASS MANAGEMENT}, author={Tilley, M. Scott and Jordan, David L. and Heiniger, Ronnie W. and Vann, Rachel and Crozier, Carl R. and Gatiboni, Luke}, year={2021} } @article{gross_vann_brown_formella_gibbs_gurganus_heiniger_hurry_jordan_leary_et al._2021, title={Agronomic management of early maturing soybeans in North Carolina}, volume={9}, ISSN={["2374-3832"]}, DOI={10.1002/cft2.20122}, abstractNote={AbstractInterest in producing indeterminate, early maturing soybean [Glycine max (L.) Merr.] varieties [maturity group (MG) ≤IV] has increased in the southeastern United States as producers seek ways to increase soybean yields. The objective of this experiment was to generate agronomic management recommendations for early maturing soybean varieties across the southeastern United States and compare these management recommendations to historical recommendations for later‐maturing varieties through identification of the optimal seeding rates, row spacing, planting dates, and fertility management. Experiments were conducted across North Carolina at seven environments in 2018 and at four environments in 2019. Two MGs were used in this study: MG III and MG IV. Data on soybean yield and soybean seed quality were collected. Row spacing recommendations were similar to recommendations for later‐maturing varieties with narrow rows providing a 7.3 bu acre–1 yield advantage across environments on average, with more pronounced yield advantages in high‐yield environments. Seeding rate impacted soybean yield but not seed quality. An economic analysis was conducted for seeding rate, suggesting that 80,000 to 120,000 seeds per acre will optimize both profit and yield across environments with May planting. Planting date sometimes impacted yield and seed quality, suggesting that earlier planting with these varieties could be critical to optimizing soybean yield and seed quality. Fertility applications at R1 (beginning of flowering) did not have an impact on soybean yield or seed quality.}, journal={CROP FORAGE & TURFGRASS MANAGEMENT}, author={Gross, MaKayla Raquel and Vann, Rachel and Brown, Austin and Formella, Adam and Gibbs, Andrea and Gurganus, Rod and Heiniger, Ryan and Hurry, Jarette and Jordan, David and Leary, Matthew and et al.}, year={2021}, month={Sep} } @article{monfort_culbreath_abney_brandenburg_royals_jordan_herbert_taylor_malone_2021, title={Effect of thiamethoxam seed treatment in peanut}, ISSN={["2374-3832"]}, DOI={10.1002/cft2.20135}, abstractNote={AbstractTobacco thrips (Frankliniella fusca) and tomato spotted wilt (TSW) orthotospovirus (family Tospoviridae, genus Orthotospovirus) can reduce peanut (Arachis hypogaea L.) yield. Systemic insecticides are applied in the seed furrow at planting and to peanut foliage to reduce injury from tobacco thrips and decrease incidence of TSW. Research was conducted in Georgia, North Carolina, South Carolina, and Virginia in 2013 and 2014 to compare the effect of the following treatments on tobacco thrips feeding injury and expression of TSW in peanut: thiamethoxam seed treatment, thiamethoxam seed treatment followed by acephate 3 weeks after planting, phorate applied in the seed furrow at planting, and a nontreated check. Tobacco thrips feeding injury and TSW incidence were significantly higher in thiamethoxam and thiamethoxam followed by acephate‐treated peanut than peanut treated with phorate. Thiamethoxan seed treatment followed by acephate resulted in significantly lower tobacco thrips feeding injury compared to thiamethoxam seed treatment alone. Yield of Virginia market type cultivars was greater when thiamethoxam was followed by acephate applied to peanut foliage or when phorate was applied compared with nontreated peanut or the seed treatment alone. Runner market type cultivars yielded higher when phorate was applied compared with nontreated peanut while peanut treated with thiamethoxam with or with acephate yielded similar to both of these treatments.}, journal={CROP FORAGE & TURFGRASS MANAGEMENT}, author={Monfort, Scott and Culbreath, Albert and Abney, Mark and Brandenburg, Rick and Royals, Brian and Jordan, David and Herbert, Ames, Jr. and Taylor, Sally and Malone, Sean}, year={2021}, month={Nov} } @article{moore_jennings_monks_jordan_leon_boyette_2021, title={Evaluating shade cloth to simulate Palmer amaranth (Amaranthus palmeri) competition in sweetpotato}, volume={69}, ISSN={["1550-2759"]}, DOI={10.1017/wsc.2021.21}, abstractNote={AbstractField studies were conducted in 2019 and 2020 to compare the effects of shade cloth light interception and Palmer amaranth (Amaranthus palmeriS. Watson) competition on ‘Covington’ sweetpotato [Ipomoea batatas(L.) Lam.]. Treatments consisted of a seven by two factorial arrangement, in which the first factor included shade cloth with an average measured light interception of 41%, 59%, 76%, and 94% andA. palmerithinned to 0.6 or 3.1 plants m−2or a nontreated weed-free check; and the second factor included shade cloth orA. palmeriremoval timing at 6 or 10 wk after planting (WAP).Amaranthus palmerilight interception peaked around 710 to 840 growing degree days (base 10 C) (6 to 7 WAP) with a maximum light interception of 67% and 84% for the 0.6 and 3.1 plants m−2densities, respectively. Increasing shade cloth light interception by 1% linearly increased yield loss by 1% for No. 1, jumbo, and total yield. Yield loss increased by 36%, 23%, and 35% as shade cloth removal was delayed from 6 to 10 WAP for No. 1, jumbo, and total yield, respectively.F-tests comparing reduced versus full models of yield loss provided no evidence that the presence of yield loss fromA. palmerilight interception caused yield loss different than that explained by the shade cloth at similar light-interception levels. Results indicate that shade cloth structures could be used to simulate Covington sweetpotato yield loss fromA. palmericompetition, and light interception could be used as a predictor for expected yield loss fromA. palmericompetition.}, number={4}, journal={WEED SCIENCE}, author={Moore, Levi D. and Jennings, Katherine M. and Monks, David W. and Jordan, David L. and Leon, Ramon G. and Boyette, Michael D.}, year={2021}, month={Jul}, pages={478–484} } @article{moore_jennings_monks_leon_boyette_jordan_2021, title={Influence of herbicides on germination and quality of Palmer amaranth (Amaranthus palmeri) seed}, volume={35}, ISSN={["1550-2740"]}, DOI={10.1017/wet.2021.71}, abstractNote={AbstractLaboratory and greenhouse studies were conducted to evaluate the effects of chemical treatments applied to Palmer amaranth seeds or gynoecious plants that retain seeds to determine seed germination and quality. Treatments applied to physiologically mature Palmer amaranth seed included acifluorfen, dicamba, ethephon, flumioxazin, fomesafen, halosulfuron, linuron, metribuzin, oryzalin, pendimethalin, pyroxasulfone, S-metolachlor, saflufenacil, trifluralin, and 2,4-D plus crop oil concentrate applied at 1× and 2× the suggested use rates from the manufacturer. Germination was reduced by 20% when 2,4-D was used, 15% when dicamba was used, and 13% when halosulfuron and pyroxasulfone were used. Use of dicamba, ethephon, halosulfuron, oryzalin, trifluralin, and 2,4-D resulted in decreased seedling length by an average of at least 50%. Due to the observed effect of dicamba, ethephon, halosulfuron, oryzalin, trifluralin, and 2,4-D, these treatments were applied to gynoecious Palmer amaranth inflorescence at the 2× registered application rates to evaluate their effects on progeny seed. Dicamba use resulted in a 24% decrease in seed germination, whereas all other treatment results were similar to those of the control. Crush tests showed that seed viability was greater than 95%, thus dicamba did not have a strong effect on seed viability. No treatments applied to Palmer amaranth inflorescence affected average seedling length; therefore, chemical treatments did not affect the quality of seeds that germinated.}, number={5}, journal={WEED TECHNOLOGY}, author={Moore, Levi D. and Jennings, Katherine M. and Monks, David W. and Leon, Ramon G. and Boyette, Michael D. and Jordan, David L.}, year={2021}, month={Oct}, pages={786–789} } @article{mahoney_jordan_hare_leon_roma-burgos_vann_jennings_everman_cahoon_2021, title={Palmer Amaranth (Amaranthus palmeri) Growth and Seed Production When in Competition with Peanut and Other Crops in North Carolina}, volume={11}, ISSN={["2073-4395"]}, url={https://doi.org/10.3390/agronomy11091734}, DOI={10.3390/agronomy11091734}, abstractNote={Palmer amaranth (Amaranthus palmeri S. Wats.) is a highly competitive weed that can be difficult to manage in many cropping systems. Research to date has not quantified the growth and development of A. palmeri in a manner that allows direct comparisons across cropping systems. Research was conducted to compare the growth, development, and seed production of A. palmeri when competing with corn (Zea mays L.), cotton (Gossypium hirsutum L.), peanut (Arachis hypogaea L.), and soybean [Glycine max (L.) Merr.] when emerging with crops or emerging three weeks after crops emerge. Regardless of when A. palmeri emerged, seed production was greatest and similar in cotton and peanut and exceeded that of corn and soybean; seed production in soybean exceeded that of corn. However, seed production was approximately 10-fold greater when A. palmeri emerged with crops compared with emergence three weeks later. These results illustrate the importance of controlling weeds during the first three weeks of the season relative to contributions of A. palmeri to the weed seed bank and is the first report comparing seed production in presence of these crops in a manner allowing a statistical comparison of seed production and highlighting the importance of crop sequence for seed bank management.}, number={9}, journal={AGRONOMY-BASEL}, publisher={MDPI AG}, author={Mahoney, Denis J. and Jordan, David L. and Hare, Andrew T. and Leon, Ramon G. and Roma-Burgos, Nilda and Vann, Matthew C. and Jennings, Katherine M. and Everman, Wesley J. and Cahoon, Charles W.}, year={2021}, month={Sep} } @article{oreja_inman_jordan_leon_2021, title={Population growth rates of weed species in response to herbicide programme intensity and their impact on weed community}, volume={9}, ISSN={["1365-3180"]}, url={https://doi.org/10.1111/wre.12509}, DOI={10.1111/wre.12509}, abstractNote={AbstractThe adoption of dicamba‐tolerant crops has reduced the challenge of controlling glyphosate‐resistantAmaranthus palmeriin these crops. However, introducing herbicide programmes with new mechanisms of action and different intensities can favour major shifts in weed communities. This can affect not only the functionality of the agroecosystem, but also resource availability to the most problematic species. The objectives of this work were to evaluate how herbicide programme structure and intensity affect (a) weed diversity, (b) population growth rate (λ) of weed species and (c) weed community structure based on λ dynamics in a dicamba‐tolerant cotton monoculture. To achieve these objectives, a cotton field experiment was established to compare four herbicide programmes from 2011 to 2018. The herbicide programmes differed in the first 4 years (i.e. glyphosate every year, alternating glyphosate and glyphosate plus dicamba every other year, glyphosate plus dicamba every year, and residual herbicide and glyphosate plus dicamba every year). During the last 4 years, all programmes received glyphosate plus dicamba. The weed seedbank was evaluated every spring and λ calculated. Environmental variation from year to year was more important in determining weed richness than herbicide programmes, which exhibited similar richness across all treatments during the eight years of the study. Regardless of herbicide programme, most species maintained λ between zero and one. Only a few species were the exception with λ values above one, such asA.palmeri,Mollugo verticillataandEleusine indica. Although glyphosate plus dicamba reduced λ for several species, this herbicide mix was less effective in reducing λ for other weeds compared with glyphosate alone, suggesting a potential antagonism that could change weed community composition. The limited changes in λ for most species suggest the capacity of weeds to adjust reproduction and survival to overcome changes in mortality rates caused by increases in herbicide use intensity.}, journal={WEED RESEARCH}, publisher={Wiley}, author={Oreja, Fernando H. and Inman, Matthew D. and Jordan, David L. and Leon, Ramon G.}, year={2021}, month={Sep} } @article{brandenburg_royals_taylor_malone_jordan_hare_2021, title={Responses of tobacco thrips and peanut to imidacloprid and fluopyram}, ISSN={["2374-3832"]}, DOI={10.1002/cft2.20116}, abstractNote={AbstractTobacco thrips (Frankliniella fusca Hinds) can reduce peanut (Arachis hypogaea L.) yield if not controlled in many instances in North Carolina and Virginia. Systemic insecticides are often applied in the seed furrow at planting to suppress tobacco thrips and protect peanut yield. Foliar sprays of acephate [N‐(methoxy[methylsulfanyl]phosphoryl)acetamide] are often made regardless of the insecticide applied at planting. Imidacloprid [(NE)‐N‐[1‐([6‐chloropyridin‐3‐yl]methyl)imidazolidin‐2‐ylidene)nitramide] plus fluopyram [N‐(2‐[3‐chloro‐5‐(trifluoromethyl)pyridin‐2‐yl]ethyl)‐2‐(trifluoromethyl)benzamide])] is registered for use in peanut but information in the peer‐reviewed literature is limited regarding its effectiveness in suppressing tobacco thrips and whether or not a foliar application of acephate is needed when this product is used. Peanut injury caused by tobacco thrips was lower when phorate [diethoxy‐(ethylsulfanylmethylsulfanyl)‐sulfanylidene‐λ5‐phosphane] or imidacloprid were applied alone compared with imidacloprid plus fluopyram in 16 trials conducted in North Carolina and Virginia from 2014 to 2020. However, all insecticides applied at planting protected peanut from injury caused by tobacco thrips well enough to prevent yield loss compared with nontreated peanut. Although acephate decreased visible injury caused by tobacco thrips, yield was not affected by acephate regardless of the systemic insecticide applied at planting. The results from these trials indicate that imidacloprid plus fluopyram offers adequate suppression of tobacco thrips to protect yield. Although acephate suppressed tobacco thrips, yield was not affected by acephate.}, journal={CROP FORAGE & TURFGRASS MANAGEMENT}, author={Brandenburg, Rick and Royals, Brian and Taylor, Sally and Malone, Sean and Jordan, David and Hare, Andrew}, year={2021}, month={Aug} } @article{moore_jennings_monks_leon_jordan_boyette_2021, title={Safety and efficacy of linuron with or without an adjuvant or S-metolachlor for POST control of Palmer amaranth (Amaranthus palmeri) in sweetpotato}, volume={35}, ISSN={["1550-2740"]}, DOI={10.1017/wet.2021.27}, abstractNote={AbstractField studies were conducted to evaluate linuron for POST control of Palmer amaranth in sweetpotato to minimize reliance on protoporphyrinogen oxidase (PPO)-inhibiting herbicides. Treatments were arranged in a two by four factorial in which the first factor consisted of two rates of linuron (420 and 700 g ai ha−1), and the second factor consisted of linuron applied alone or in combinations of linuron plus a nonionic surfactant (NIS; 0.5% vol/vol), linuron plus S-metolachlor (800 g ai ha−1), or linuron plus NIS plus S-metolachlor. In addition, S-metolachlor alone and nontreated weedy and weed-free checks were included for comparison. Treatments were applied to ‘Covington’ sweetpotato 8 d after transplanting (DAP). S-metolachlor alone provided poor Palmer amaranth control because emergence had occurred at applications. All treatments that included linuron resulted in at least 98% and 91% Palmer amaranth control 1 and 2 wk after treatment (WAT), respectively. Including NIS with linuron did not increase Palmer amaranth control compared to linuron alone, but it resulted in greater sweetpotato injury and subsequently decreased total sweetpotato yield by 25%. Including S-metolachlor with linuron resulted in the greatest Palmer amaranth control 4 WAT, but increased crop foliar injury to 36% 1 WAT compared to 17% foliar injury from linuron alone. Marketable and total sweetpotato yields were similar between linuron alone and linuron plus S-metolachlor or S-metolachlor plus NIS treatments, though all treatments resulted in at least 39% less total yield than the weed-free check resulting from herbicide injury and/or Palmer amaranth competition. Because of the excellent POST Palmer amaranth control from linuron 1 WAT, a system that includes linuron applied 7 DAP followed by S-metolachlor applied 14 DAP could help to extend residual Palmer amaranth control further into the critical period of weed control while minimizing sweetpotato injury.}, number={3}, journal={WEED TECHNOLOGY}, author={Moore, Levi D. and Jennings, Katherine M. and Monks, David W. and Leon, Ramon G. and Jordan, David L. and Boyette, Michael D.}, year={2021}, month={Jun}, pages={471–475} } @article{moore_jennings_monks_jordan_boyette_leon_mahoney_everman_cahoon_2021, title={Susceptibility of Palmer amaranth accessions in North Carolina to atrazine, dicamba, S-metolachlor, and 2,4-D}, volume={11}, ISSN={["2374-3832"]}, url={https://doi.org/10.1002/cft2.20136}, DOI={10.1002/cft2.20136}, abstractNote={Core Ideas All of the 120 accessions of Palmer amaranth collected in the Coastal Plain of North Carolina were controlled by atrazine and dicamba applied at field use rates in the greenhouse. Reduced sensitivity among accessions was noted when S‐metolachlor and 2,4‐D were applied to Palmer amaranth at field use rates in the greenhouse. Additional research is needed to determine if reduced sensitivity of Palmer amaranth to S‐metolachlor and 2,4‐D is associated with evolved resistance. }, journal={CROP FORAGE & TURFGRASS MANAGEMENT}, publisher={Wiley}, author={Moore, Levi D. and Jennings, Katherine M. and Monks, David W. and Jordan, David L. and Boyette, Michael D. and Leon, Ramon G. and Mahoney, Dennis J. and Everman, Wesley J. and Cahoon, Charles W.}, year={2021}, month={Nov} } @article{royals_brandenburg_hare_jordan_taylor_malone_2020, title={Efficacy of chlorantraniliprole on southern corn rootworm in peanut}, volume={6}, ISSN={["2374-3832"]}, DOI={10.1002/cft2.20045}, abstractNote={The authors report no conflicts of interest.}, number={1}, journal={CROP FORAGE & TURFGRASS MANAGEMENT}, author={Royals, Brian and Brandenburg, Rick and Hare, Andrew and Jordan, David and Taylor, Sally and Malone, Sean}, year={2020} } @article{inman_vann_fisher_gannon_jordan_jennings_2021, title={Evaluation of dicamba retention in spray tanks and its impact on flue-cured tobacco}, volume={35}, ISSN={["1550-2740"]}, url={http://dx.doi.org/10.1017/wet.2020.73}, DOI={10.1017/wet.2020.73}, abstractNote={AbstractIn recent years, there has been increased use of dicamba due to the introduction of dicamba-resistant cotton and soybean in the United States. Therefore, there is a potential increase in off-target movement of dicamba and injury to sensitive crops. Flue-cured tobacco is extremely sensitive to auxin herbicides, particularly dicamba. In addition to yield loss, residue from drift or equipment contamination can have severe repercussions for the marketability of the crop. Studies were conducted in 2016, 2017, and 2018 in North Carolina to evaluate spray-tank cleanout efficiency of dicamba using various cleaning procedures. No difference in dicamba recovery was observed regardless of dicamba formulation and cleaning agent. Dicamba residue decreased with the number of rinses. There was no difference in dicamba residue recovered from the third rinse compared with residue from the tank after being refilled for subsequent tank use. Recovery ranged from 2% to 19% of the original concentration rate among the three rinses. Field studies were also conducted in 2018 to evaluate flue-cured tobacco response to reduced rates of dicamba ranging, from 1/5 to 1/10,000 of a labeled rate. Injury and yield reductions varied by environment and application timing. When exposed to 1/500 of a labeled rate at 7 and 11 wk after transplanting, tobacco injury ranged from 39% to 53% and 10% to 16% 24 days after application, respectively. The maximum yield reduction was 62%, with a 55% reduction in value when exposed to 112 g ha−1 of dicamba. Correlations showed significant relationships between crop injury assessment and yield and value reductions, with Pearson values ranging from 0.24 to 0.63. These data can provide guidance to growers and stakeholders and emphasize the need for diligent stewardship when using dicamba technology.}, number={1}, journal={WEED TECHNOLOGY}, publisher={Cambridge University Press (CUP)}, author={Inman, Matthew D. and Vann, Matthew C. and Fisher, Loren R. and Gannon, Travis W. and Jordan, David L. and Jennings, Katie M.}, year={2021}, month={Feb}, pages={35–42} } @article{moore_jennings_monks_boyette_jordan_leon_2021, title={Herbicide systems including linuron for Palmer amaranth (Amaranthus palmeri) control in sweetpotato}, volume={35}, ISSN={["1550-2740"]}, DOI={10.1017/wet.2020.63}, abstractNote={AbstractField studies were conducted to determine sweetpotato tolerance to and weed control from management systems that included linuron. Treatments included flumioxazin preplant (107 g ai ha−1) followed by (fb) S-metolachlor (800 g ai ha−1), oryzalin (840 g ai ha−1), or linuron (280, 420, 560, 700, and 840 g ai ha−1) alone or mixed with S-metolachlor or oryzalin applied 7 d after transplanting. Weeds did not emerge before the treatment applications. Two of the four field studies were maintained weed-free throughout the season to evaluate sweetpotato tolerance without weed interference. The herbicide program with the greatest sweetpotato yield was flumioxazin fb S-metolachlor. Mixing linuron with S-metolachlor did not improve Palmer amaranth management and decreased marketable yield by up to 28% compared with flumioxazin fb S-metolachlor. Thus, linuron should not be applied POST in sweetpotato if Palmer amaranth has not emerged at the time of application.}, number={1}, journal={WEED TECHNOLOGY}, author={Moore, Levi D. and Jennings, Katherine M. and Monks, David W. and Boyette, Michael D. and Jordan, David L. and Leon, Ramon G.}, year={2021}, month={Feb}, pages={49–56} } @article{kaufman_jordan_reberg-horton_dean_shew_brandenburg_anco_mehl_taylor_balota_et al._2020, title={Identifying interest, risks, and impressions of organic peanut production: A survey of conventional farmers in the Virginia-Carolina region}, volume={6}, ISSN={["2374-3832"]}, DOI={10.1002/cft2.20042}, abstractNote={Crop, Forage & Turfgrass ManagementVolume 6, Issue 1 e20042 CROP MANAGEMENT—BRIEFS Identifying interest, risks, and impressions of organic peanut production: A survey of conventional farmers in the Virginia–Carolina region Amanda A. Kaufman, Amanda A. Kaufman Department of Food, Bioprocessing, and Nutrition Sciences, North Carolina State University, Box 7624, Raleigh, NC, 27695 USASearch for more papers by this authorDavid L. Jordan, Corresponding Author David L. Jordan david_jordan@ncsu.edu orcid.org/0000-0003-4786-2727 Department of Crop and Soil Sciences, North Carolina State University, Box 7620, Raleigh, NC, 27695 USA Correspondence Department of Crop and Soil Sciences, North Carolina State University, Box 7620, Raleigh, NC 27695 Email: david_jordan@ncsu.eduSearch for more papers by this authorChris Reberg-Horton, Chris Reberg-Horton Department of Crop and Soil Sciences, North Carolina State University, Box 7620, Raleigh, NC, 27695 USASearch for more papers by this authorLisa L. Dean, Lisa L. Dean Market Quality and Handling Research Unit, ARS, SEA, USDA, Raleigh, NC, 27695 USASearch for more papers by this authorBarbara B. Shew, Barbara B. Shew Department of Entomology and Plant Pathology, North Carolina State University, Box 7613, Raleigh, NC, 27695 USASearch for more papers by this authorRick L. Brandenburg, Rick L. Brandenburg Department of Entomology and Plant Pathology, North Carolina State University, Box 7613, Raleigh, NC, 27695 USASearch for more papers by this authorDan Anco, Dan Anco Edisto Research and Extension Center, Clemson University, 64 Research Road, Blackville, SC, 29817 USASearch for more papers by this authorHillary Mehl, Hillary Mehl Tidewater Agricultural Research and Extension Center, 6321 Holland Road, Suffolk, VA, 23437 USASearch for more papers by this authorSally Taylor, Sally Taylor Tidewater Agricultural Research and Extension Center, 6321 Holland Road, Suffolk, VA, 23437 USASearch for more papers by this authorMaria Balota, Maria Balota orcid.org/0000-0003-4626-0193 Tidewater Agricultural Research and Extension Center, 6321 Holland Road, Suffolk, VA, 23437 USASearch for more papers by this authorL. Suzanne Goodell, L. Suzanne Goodell Department of Food, Bioprocessing, and Nutrition Sciences, North Carolina State University, Box 7624, Raleigh, NC, 27695 USASearch for more papers by this authorJonathan Allen, Jonathan Allen Department of Food, Bioprocessing, and Nutrition Sciences, North Carolina State University, Box 7624, Raleigh, NC, 27695 USASearch for more papers by this author Amanda A. Kaufman, Amanda A. Kaufman Department of Food, Bioprocessing, and Nutrition Sciences, North Carolina State University, Box 7624, Raleigh, NC, 27695 USASearch for more papers by this authorDavid L. Jordan, Corresponding Author David L. Jordan david_jordan@ncsu.edu orcid.org/0000-0003-4786-2727 Department of Crop and Soil Sciences, North Carolina State University, Box 7620, Raleigh, NC, 27695 USA Correspondence Department of Crop and Soil Sciences, North Carolina State University, Box 7620, Raleigh, NC 27695 Email: david_jordan@ncsu.eduSearch for more papers by this authorChris Reberg-Horton, Chris Reberg-Horton Department of Crop and Soil Sciences, North Carolina State University, Box 7620, Raleigh, NC, 27695 USASearch for more papers by this authorLisa L. Dean, Lisa L. Dean Market Quality and Handling Research Unit, ARS, SEA, USDA, Raleigh, NC, 27695 USASearch for more papers by this authorBarbara B. Shew, Barbara B. Shew Department of Entomology and Plant Pathology, North Carolina State University, Box 7613, Raleigh, NC, 27695 USASearch for more papers by this authorRick L. Brandenburg, Rick L. Brandenburg Department of Entomology and Plant Pathology, North Carolina State University, Box 7613, Raleigh, NC, 27695 USASearch for more papers by this authorDan Anco, Dan Anco Edisto Research and Extension Center, Clemson University, 64 Research Road, Blackville, SC, 29817 USASearch for more papers by this authorHillary Mehl, Hillary Mehl Tidewater Agricultural Research and Extension Center, 6321 Holland Road, Suffolk, VA, 23437 USASearch for more papers by this authorSally Taylor, Sally Taylor Tidewater Agricultural Research and Extension Center, 6321 Holland Road, Suffolk, VA, 23437 USASearch for more papers by this authorMaria Balota, Maria Balota orcid.org/0000-0003-4626-0193 Tidewater Agricultural Research and Extension Center, 6321 Holland Road, Suffolk, VA, 23437 USASearch for more papers by this authorL. Suzanne Goodell, L. Suzanne Goodell Department of Food, Bioprocessing, and Nutrition Sciences, North Carolina State University, Box 7624, Raleigh, NC, 27695 USASearch for more papers by this authorJonathan Allen, Jonathan Allen Department of Food, Bioprocessing, and Nutrition Sciences, North Carolina State University, Box 7624, Raleigh, NC, 27695 USASearch for more papers by this author First published: 14 June 2020 https://doi.org/10.1002/cft2.20042Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Volume6, Issue12020e20042 RelatedInformation}, number={1}, journal={CROP FORAGE & TURFGRASS MANAGEMENT}, author={Kaufman, Amanda A. and Jordan, David L. and Reberg-Horton, Chris and Dean, Lisa L. and Shew, Barbara B. and Brandenburg, Rick L. and Anco, Dan and Mehl, Hillary and Taylor, Sally and Balota, Maria and et al.}, year={2020} } @article{hare_jordan_leon_edmisten_post_cahoon_everman_mahoney_inman_2020, title={Influence of timing and intensity of weed management on crop yield and contribution to weed emergence in cotton the following year}, volume={6}, ISSN={["2374-3832"]}, url={https://doi.org/10.1002/cft2.20021}, DOI={10.1002/cft2.20021}, abstractNote={AbstractAdequate weed control is important in protecting crop yield and allowing efficient harvest in North Carolina. Data in the literature are limited with respect to direct comparisons of weed control and yield across multiple crops. Research is also limited in terms of documenting the impact of weed control in one crop on weed populations in the crop planted the following season. Experiments were conducted in North Carolina to determine weed control and yield of corn (Zea mays L.), cotton (Gossypium hirsutum L.), and soybean [Glycine max (L.) Merr.] in the same experiment when herbicides were applied postemergence at different timings (Year 1) and to determine how weed control translated into weed populations and cotton yield the following year (Year 2). Herbicides were applied 2 or 6 wk after planting (WAP); 2 and 4 WAP; 4 and 6 WAP; and 2, 4, and 6 WAP. At Lewiston‐Woodville, common ragweed (Ambrosia artemisiifolia L.) and Texas millet (Urochloa texana L.) were present. At Rocky Mount, Palmer amaranth (Amanthus palmeri S. Wats) and large crabgrass (Digitaria sanguinalis L.) were present. A single postemergence application of herbicide protected yield from weed interference in corn, whereas in most instances multiple herbicide applications were needed in cotton and to a degree in soybean. Weed densities in Year 2 in cotton were negatively correlated with weed control the previous year in corn, cotton, and soybean. Densities of common ragweed and Palmer amaranth 3 WAP in Year 2 were higher in cotton when the preceding crop was cotton or soybean rather than corn when herbicides were not applied; no difference was noted when comparing cotton and soybean. In some instances, sequential applications of herbicides resulted in lower weed densities the following year in cotton. These results demonstrate the importance of timely, sequential herbicide applications for weed control in cotton and soybean and in some instances the positive benefits on weed populations the following year in cotton.}, number={1}, journal={CROP FORAGE & TURFGRASS MANAGEMENT}, publisher={Wiley}, author={Hare, Andrew T. and Jordan, David L. and Leon, Ramon G. and Edmisten, Keith L. and Post, Angela R. and Cahoon, Charles W. and Everman, Wesley J. and Mahoney, Denis J. and Inman, Matthew D.}, year={2020} } @article{anco_thomas_jordan_shew_monfort_mehl_small_wright_tillman_dufault_et al._2020, title={Peanut Yield Loss in the Presence of Defoliation Caused by Late or Early Leaf Spot}, volume={104}, ISSN={["1943-7692"]}, DOI={10.1094/PDIS-11-19-2286-RE}, abstractNote={ Late and early leaf spot, respectively caused by Nothopassalora personata and Passalora arachidicola, are damaging diseases of peanut (Arachis hypogaea) capable of defoliating canopies and reducing yield. Although one of these diseases may be more predominant in a given area, both are important on a global scale. To assist informed management decisions and quantify relationships between end-of-season defoliation and yield loss, meta-analyses were conducted over 140 datasets meeting established criteria. Slopes of proportion yield loss with increasing defoliation were estimated separately for Virginia and runner market type cultivars. Yield loss for Virginia types was described by an exponential function over the range of defoliation levels, with a loss increase of 1.2 to 2.2% relative to current loss levels per additional percent defoliation. Results for runner market type cultivars showed yield loss to linearly increase 2.2 to 2.8% per 10% increase in defoliation for levels up to approximately 95% defoliation, after which the rate of yield loss was exponential. Defoliation thresholds to prevent economic yield loss for Virginia and runner types were estimated at 40 and 50%, respectively. Although numerous factors remain important in mitigating overall yield losses, the integration of these findings should aid recommendations about digging under varying defoliation intensities and peanut maturities to assist in minimizing yield losses. }, number={5}, journal={PLANT DISEASE}, author={Anco, Daniel J. and Thomas, James S. and Jordan, David L. and Shew, Barbara B. and Monfort, W. Scott and Mehl, Hillary L. and Small, Ian M. and Wright, David L. and Tillman, Barry L. and Dufault, Nicholas S. and et al.}, year={2020}, month={May}, pages={1390–1399} } @article{jordan_hare_johnson_alston_alston_ambrose_callis_corbett_hoggard_stevens_et al._2020, title={Peanut and soybean response to cropping systems including corn, cotton, and grain sorghum}, volume={6}, ISSN={["2374-3832"]}, DOI={10.1002/cft2.20041}, abstractNote={The authors declare no conflict of interest.}, number={1}, journal={CROP FORAGE & TURFGRASS MANAGEMENT}, author={Jordan, David and Hare, Andrew and Johnson, Dewayne and Alston, Joel and Alston, Trevor and Ambrose, Derek and Callis, David and Corbett, Tommy and Hoggard, Riley and Stevens, Brian and et al.}, year={2020} } @article{basinger_jennings_hestir_monks_jordan_everman_2020, title={Phenology affects differentiation of crop and weed species using hyperspectral remote sensing}, volume={34}, ISSN={["1550-2740"]}, url={https://doi.org/10.1017/wet.2020.92}, DOI={10.1017/wet.2020.92}, abstractNote={AbstractThe effect of plant phenology and canopy structure of four crops and four weed species on reflectance spectra were evaluated in 2016 and 2017 using in situ spectroscopy. Leaf-level and canopy-level reflectance were collected at multiple phenologic time points in each growing season. Reflectance values at 2 wk after planting (WAP) in both years indicated strong spectral differences between species across the visible (VIS; 350–700 nm), near-infrared (NIR; 701–1,300 nm), shortwave-infrared I (SWIR1; 1,301–1,900 nm), and shortwave-infrared II (SWIR2; 1,901–2,500 nm) regions. Results from this study indicate that plant spectral reflectance changes with plant phenology and is influenced by plant biophysical characteristics. Canopy-level differences were detected in both years across all dates except for 1 WAP in 2017. Species with similar canopy types (e.g., broadleaf prostrate, broadleaf erect, or grass/sedge) were more readily discriminated from species with different canopy types. Asynchronous phenology between species also resulted in spectral differences between species. SWIR1 and SWIR2 wavelengths are often not included in multispectral sensors but should be considered for species differentiation. Results from this research indicate that wavelengths in SWIR1 and SWIR2 in conjunction with VIS and NIR reflectance can provide differentiation across plant phenologies and, therefore should be considered for use in future sensor technologies for species differentiation.}, number={6}, journal={WEED TECHNOLOGY}, author={Basinger, Nicholas T. and Jennings, Katherine M. and Hestir, Erin L. and Monks, David W. and Jordan, David L. and Everman, Wesley J.}, year={2020}, month={Dec}, pages={897–908} } @article{jordan_hardy_barnes_corbett_2020, title={Potential economic value for peanut by increasing soil pH in North Carolina}, volume={6}, ISSN={["2374-3832"]}, DOI={10.1002/cft2.20012}, abstractNote={The authors declare no conflict of interest.}, number={1}, journal={CROP FORAGE & TURFGRASS MANAGEMENT}, author={Jordan, David and Hardy, David and Barnes, Steve and Corbett, Tommy}, year={2020} } @article{hare_jordan_edmisten_leon_post_vann_dunphy_heiniger_collins_washburn_2020, title={Response of agronomic crops to planting date and double-cropping with wheat}, volume={112}, ISSN={["1435-0645"]}, url={https://doi.org/10.1002/agj2.20164}, DOI={10.1002/agj2.20164}, abstractNote={AbstractPlanting date can affect crop yield and is an important management decision for practitioners. Although wheat (Triticum aestivum L.) and soybean [Glycine max (L.) Merr.] can be effectively double‐cropped in North Carolina, if commodity prices and projected economic returns are higher for crops other than soybean, growers might consider a nontraditional, double‐crop system. Direct comparisons of major agronomic crops with different planting dates or in a double‐crop system with wheat are limited in North Carolina. Therefore, research was conducted in North Carolina from 2013 through 2017 to determine yield potential of corn (Zea mays L.), cotton (Gossypium hirsutum L.), grain sorghum [Sorghum bicolor (L.) Moench], peanut (Arachis hypogaea L.), and soybean planted at two dates within the recommended planting window for full‐season production versus planting these crops after wheat harvest. The experimental design was a split plot, with summer crop serving as the whole plot unit and planting date within a crop serving as the subplot unit. Yield of corn, cotton, grain sorghum, peanut, and soybean in full‐season production exceeded that of double‐cropping with wheat in 5, 5, 2, 4, and 5 yr out of 5 yr of the study, respectively. Estimated economic returns were generated using the 10‐yr average (2008–2017) summer crop prices with the 10‐yr average wheat price. When considering all possible combinations of years and crops (n = 25), in only 20% of the possible combinations was the economic return of the double‐cropping system greater than economic return of full‐season crop production when compared with at least one of the planting dates within the traditional planting window.}, number={3}, journal={AGRONOMY JOURNAL}, publisher={Wiley}, author={Hare, Andrew T. and Jordan, David L. and Edmisten, Keith L. and Leon, Ramon G. and Post, Angela R. and Vann, Rachel and Dunphy, E. James and Heiniger, Ronnie and Collins, Guy and Washburn, Derek}, year={2020}, pages={1972–1980} } @article{jordan_dunne_stalker_shew_brandenburg_anco_mehl_taylor_balota_2020, title={Risk to sustainability of pest management tools in peanut}, volume={5}, ISSN={["2471-9625"]}, DOI={10.1002/ael2.20018}, abstractNote={AbstractA diversity of pests can adversely affect peanut (Arachis hypogaea L.) yield, quality, and financial return. Farmers rely heavily on applied chemicals to suppress many of the economically important pests present in peanut. The effectiveness of this approach to pest management may not be sustainable, however, due to evolved resistance in pests to chemicals, reluctance of basic chemical manufacturers to invest in product development because of the relatively small market for peanut compared with other crops, cost to initially register or re‐register chemicals, and the desire for peanut buyers and processors to capture international markets that may have varying agrochemical residue restrictions for peanut. Heavy reliance on chemical control could leave peanut production systems vulnerable to yield loss; thus, a more concerted research effort is needed to increase the number and availability of nonchemical tools that protect peanut from pests in order to ensure long‐term sustainability of peanut production systems.}, number={1}, journal={AGRICULTURAL & ENVIRONMENTAL LETTERS}, author={Jordan, David L. and Dunne, Jeffrey and Stalker, H. Thomas and Shew, Barbara B. and Brandenburg, Rick L. and Anco, Dan and Mehl, Hillary and Taylor, Sally and Balota, Maria}, year={2020} } @article{mahoney_jordan_roma-burgos_jennings_leon_vann_everman_cahoon_2020, title={Susceptibility of Palmer amaranth (Amaranthus palmeri) to herbicides in accessions collected from the North Carolina Coastal Plain}, volume={68}, ISSN={["1550-2759"]}, url={http://dx.doi.org/10.1017/wsc.2020.67}, DOI={10.1017/wsc.2020.67}, abstractNote={AbstractPalmer amaranth (Amaranthus palmeri S. Watson) populations resistant to acetolactate synthase (ALS)-inhibiting herbicides and glyphosate are fairly common throughout the state of North Carolina (NC). This has led farm managers to rely more heavily on herbicides with other sites of action (SOA) for A. palmeri control, especially protoporphyrinogen oxidase and glutamine synthetase inhibitors. In the fall of 2016, seeds from A. palmeri populations were collected from the NC Coastal Plain, the state’s most prominent agricultural region. In separate experiments, plants with 2 to 4 leaves from the 110 populations were treated with field use rates of glyphosate, glufosinate-ammonium, fomesafen, mesotrione, or thifensulfuron-methyl. Percent visible control and survival were evaluated 3 wk after treatment. Survival frequencies were highest following glyphosate (99%) or thifensulfuron-methyl (96%) treatment. Known mutations conferring resistance to ALS inhibitors were found in populations surviving thifensulfuron-methyl application (Ala-122-Ser, Pro-197-Ser, Trp-574-Leu, and/or Ser-653-Asn), in addition to a new mutation (Ala-282-Asp) that requires further investigation. Forty-two populations had survivors after mesotrione application, with one population having 17% survival. Four populations survived fomesafen treatment, while none survived glufosinate. Dose–response studies showed an increase in fomesafen needed to kill 50% of two populations (LD50); however, these rates were far below the field use rate (less than 5 g ha−1). In two populations following mesotrione dose–response studies, a 2.4- to 3.3-fold increase was noted, with LD90 values approaching the field use rate (72.8 and 89.8 g ha−1). Screening of the progeny of individuals surviving mesotrione confirmed the presence of resistance alleles, as there were a higher number of survivors at the 1X rate compared with the parent population, confirming resistance to mesotrione. These data suggest A. palmeri resistant to chemistries other than glyphosate and thifensulfuron-methyl are present in NC, which highlights the need for weed management approaches to mitigate the evolution and spread of herbicide-resistant populations.}, number={6}, journal={WEED SCIENCE}, publisher={Cambridge University Press (CUP)}, author={Mahoney, Denis J. and Jordan, David L. and Roma-Burgos, Nilda and Jennings, Katherine M. and Leon, Ramon G. and Vann, Matthew C. and Everman, Wesley J. and Cahoon, Charles W.}, year={2020}, month={Nov}, pages={582–593} } @article{mahoney_jordan_hare_roma-burgos_jennings_leon_vann_everman_cahoon_2021, title={The influence of soybean population and POST herbicide application timing on in-season and subsequent-season Palmer amaranth (Amaranthus palmeri) control and economic returns}, volume={35}, ISSN={["1550-2740"]}, DOI={10.1017/wet.2020.87}, abstractNote={AbstractOverreliance on herbicides for weed control has led to the evolution of herbicide-resistant Palmer amaranth populations. Farm managers should consider the long-term consequences of their short-term management decisions, especially when considering the soil weed seedbank. The objectives of this research were to (1) determine how soybean population and POST herbicide application timing affects in-season Palmer amaranth control and soybean yield, and (2) how those variables influence Palmer amaranth densities and cotton yields the following season. Soybeans were planted (19-cm row spacing) at a low-, medium-, and high-density population (268,000, 546,000, and 778,000 plants ha–1, respectively). Fomesafen and clethodim (280 and 210 g ai ha–1, respectively) were applied at the VE, V1, or V2 to V3 soybean growth stage. Nontreated plots were also included to assess the effect of soybean population alone. The following season, cotton was planted into these plots so as to understand the effects of soybean planting population on Palmer amaranth densities in the subsequent crop. When an herbicide application occurred at the V1 or V2 to V3 soybean stage, weed control in the high-density soybean population increased 17% to 23% compared to the low-density population. Economic return was not influenced by soybean population and was increased 72% to 94% with herbicide application compared to no treatment. In the subsequent cotton crop, Palmer amaranth densities were 24% to 39% lower 3 wk after planting when following soybean sprayed with herbicides compared to soybean without herbicides. Additionally, Palmer amaranth densities in cotton were 19% lower when soybean was treated at the VE stage compared to later stages. Thus, increasing soybean population can improve Palmer amaranth control without adversely affecting economic returns and can reduce future weed densities. Reducing the weed seedbank and selection pressure from herbicides are critical in mitigating resistance evolution.}, number={1}, journal={WEED TECHNOLOGY}, author={Mahoney, Denis J. and Jordan, David L. and Hare, Andrew T. and Roma-Burgos, Nilda and Jennings, Katherine M. and Leon, Ramon G. and Vann, Matthew C. and Everman, Wesley J. and Cahoon, Charles W.}, year={2021}, month={Feb}, pages={106–112} } @article{basinger_jennings_monks_jordan_everman_hestir_waldschmidt_smith_brownie_2019, title={Interspecific and intraspecific interference of Palmer amaranth (Amaranthus palmeri) and large crabgrass (Digitaria sanguinalis) in sweetpotato}, volume={67}, ISSN={["1550-2759"]}, DOI={10.1017/wsc.2019.16}, abstractNote={AbstractField studies were conducted in 2016 and 2017 in Clinton, NC, to determine the interspecific and intraspecific interference of Palmer amaranth (Amaranthus palmeri S. Watson) or large crabgrass [Digitaria sanguinalis (L.) Scop.] in ‘Covington’ sweetpotato [Ipomoea batatas (L.) Lam.]. Amaranthus palmeri and D. sanguinalis were established 1 d after sweetpotato transplanting and maintained season-long at 0, 1, 2, 4, 8 and 0, 1, 2, 4, 16 plants m−1 of row in the presence and absence of sweetpotato, respectively. Predicted yield loss for sweetpotato was 35% to 76% for D. sanguinalis at 1 to 16 plants m−1 of row and 50% to 79% for A. palmeri at 1 to 8 plants m−1 of row. Weed dry biomass per meter of row increased linearly with increasing weed density. Individual dry biomass of A. palmeri and D. sanguinalis was not affected by weed density when grown in the presence of sweetpotato. When grown without sweetpotato, individual weed dry biomass decreased 71% and 62% from 1 to 4 plants m−1 row for A. palmeri and D. sanguinalis, respectively. Individual weed dry biomass was not affected above 4 plants m−1 row to the highest densities of 8 and 16 plants m−1 row for A. palmeri and D. sanguinalis, respectively.}, number={4}, journal={WEED SCIENCE}, author={Basinger, Nicholas T. and Jennings, Katherine M. and Monks, David W. and Jordan, David L. and Everman, Wesley J. and Hestir, Erin L. and Waldschmidt, Matthew D. and Smith, Stephen C. and Brownie, Cavell}, year={2019}, month={Jul}, pages={426–432} } @article{basinger_jennings_monks_jordan_everman_hestir_bertucci_brownie_2019, title={Large crabgrass (Digitaria sanguinalis) and Palmer amaranth (Amaranthus palmeri) intraspecific and interspecific interference in soybean}, volume={67}, ISSN={["1550-2759"]}, url={https://doi.org/10.1017/wsc.2019.43}, DOI={10.1017/wsc.2019.43}, abstractNote={AbstractField studies were conducted in 2016 and 2017 at Clinton, NC, to quantify the effects of season-long interference of large crabgrass [Digitaria sanguinalis (L.) Scop.] and Palmer amaranth (Amaranthus palmeri S. Watson) on ‘AG6536’ soybean [Glycine max (L.) Merr.]. Weed density treatments consisted of 0, 1, 2, 4, and 8 plants m−2 for A. palmeri and 0, 1, 2, 4, and 16 plants m−2 for D. sanguinalis with (interspecific interference) and without (intraspecific interference) soybean to determine the impacts on weed biomass, soybean biomass, and seed yield. Biomass per square meter increased with increasing weed density for both weed species with and without soybean present. Biomass per square meter of D. sanguinalis was 617% and 37% greater when grown without soybean than with soybean, for 1 and 16 plants m−2 respectively. Biomass per square meter of A. palmeri was 272% and 115% greater when grown without soybean than with soybean for 1 and 8 plants m−2, respectively. Biomass per plant for D. sanguinalis and A. palmeri grown without soybean was greatest at the 1 plant m−2 density. Biomass per plant of D. sanguinalis plants across measured densities was 33% to 83% greater when grown without soybean compared with biomass per plant when soybean was present for 1 and 16 plants m−2, respectively. Similarly, biomass per plant for A. palmeri was 56% to 74% greater when grown without soybean for 1 and 8 plants m−2, respectively. Biomass per plant of either weed species was not affected by weed density when grown with soybean due to interspecific competition with soybean. Yield loss for soybean grown with A. palmeri ranged from 14% to 37% for densities of 1 to 8 plants m−2, respectively, with a maximum yield loss estimate of 49%. Similarly, predicted loss for soybean grown with D. sanguinalis was 0 % to 37% for densities of 1 to 16 m−2 with a maximum yield loss estimate of 50%. Soybean biomass was not affected by weed species or density. Results from these studies indicate that A. palmeri is more competitive than D. sanguinalis at lower densities, but that similar yield loss can occur when densities greater than 4 plants m−2 of either weed are present.}, number={6}, journal={WEED SCIENCE}, author={Basinger, Nicholas T. and Jennings, Katherine M. and Monks, David W. and Jordan, David L. and Everman, Wesley J. and Hestir, Erin L. and Bertucci, Matthew B. and Brownie, Cavell}, year={2019}, month={Nov}, pages={649–656} } @article{jani_mulvaney_balkcom_wood_jordan_wood_devkota_2020, title={Peanut residues supply minimal plant-available nitrogen on a major soil series in the USA peanut basin}, volume={36}, ISSN={["1475-2743"]}, DOI={10.1111/sum.12563}, abstractNote={AbstractField observations have shown that a substantial portion of peanut leaves abscise in windrows during pod curing, leading to an uneven distribution of leaves and stems when intact residues are spread during harvest. Possible differences in nitrogen (N) mineralization rates between peanut leaf and stem residues may lead to spatial and temporal variability in available N during subsequent crops. The objective of this study was to quantify N mineralization in soil amended with different peanut residue components under simulated conventional and conservation tillage practices. A 252‐day microlysimeter incubation was conducted in which peanut leaves, stems and a 1:1 mixture of leaves:stems from three varieties were incorporated or placed on the soil surface to simulate conventional or conservation tillage, respectively. Soils were periodically leached to assess N mineralization compared with a soil‐only control. Nitrogen mineralization was only affected by residue component. Averaged over variety and residue placement, soil amended with leaves mineralized 10% more N relative to the control or soil containing stems. It was estimated that leaves supplied 25 kg N ha−1 over 252 days at 0–15 cm soil depth, which would likely be insufficient to induce a yield response by a subsequent crop. This study suggests that uneven distribution of peanut leaf and stem residues following harvest causes only minor spatial and temporal variability in available N during subsequent crop growth. These results support the growing body of evidence indicating that peanut residue N contributions to subsequent crops are negligible in the peanut basin of the south‐eastern USA.}, number={2}, journal={SOIL USE AND MANAGEMENT}, author={Jani, Arun D. and Mulvaney, Michael J. and Balkcom, Kipling S. and Wood, Charles Wesley and Jordan, David L. and Wood, Brenda H. and Devkota, Pratap}, year={2020}, month={Apr}, pages={274–284} } @article{jordan_hare_2019, title={Response of Peanut to Foliar Application of Sodium Silicate}, volume={5}, ISSN={["2374-3832"]}, DOI={10.2134/cftm2019.07.0056}, abstractNote={Core Ideas Sodium silicate applied after emergence to peanut does not increase yield. When pests are controlled via conventional production, systems sodium silicate does not influence peanut yield. Sodium silicate demonstrated no value in typical peanut production systems in North Carolina.}, number={1}, journal={CROP FORAGE & TURFGRASS MANAGEMENT}, author={Jordan, David L. and Hare, Andrew T.}, year={2019}, month={Nov} } @article{jordan_johnson_corbett_2019, title={Response of Two Virginia Market Type Peanut Cultivars to Planting and Digging Dates in North Carolina}, volume={5}, ISSN={["2374-3832"]}, DOI={10.2134/cftm2019.01.0003}, abstractNote={Core Ideas Planting peanut in May results in greater economic value than planting peanut in June in North Carolina. Delaying digging into October was needed for the cultivar Perry while digging in early October was adequate to optimize economic return for the cultivar CHAMPS. When planting is delayed, economic value is optimized with later digging dates.}, number={1}, journal={CROP FORAGE & TURFGRASS MANAGEMENT}, author={Jordan, David and Johnson, P. Dewayne and Corbett, Tommy}, year={2019}, month={May} } @article{jordan_hare_roberson_ward_shew_brandenburg_anco_thomas_balota_mehl_et al._2019, title={Survey of Practices by Growers in the Virginia-Carolina Region Regarding Digging and Harvesting Peanut}, volume={5}, ISSN={["2374-3832"]}, DOI={10.2134/cftm2019.07.0057}, abstractNote={Core Ideas Harvesting peanut requires approximately twice as much time to complete as the time required for digging peanut. Fifty-six percent of growers predicted when optimum yield would occur based on the sample provided within the recommended timeframe. Reported yield was positively correlated with the use of prohexadione calcium.}, number={1}, journal={CROP FORAGE & TURFGRASS MANAGEMENT}, author={Jordan, David L. and Hare, Andrew T. and Roberson, Gary T. and Ward, Jason and Shew, Barbara B. and Brandenburg, Rick L. and Anco, Dan and Thomas, James and Balota, Maria and Mehl, Hillary and et al.}, year={2019}, month={Nov} } @article{mahoney_jordan_hare_leon_vann_burgos_jennings_2019, title={The Effect of Nozzle Selection and Carrier Volume on Weed Control in Soybean in North Carolina}, volume={5}, ISSN={["2374-3832"]}, DOI={10.2134/cftm2019.05.0037}, abstractNote={Core Ideas Nozzle selection did not affect PRE or POST herbicide efficacy. Carrier volumes from 7.5 to 60 gal/acre generally provided similar weed control. Soybean yield was not affected by nozzle selection or carrier volume. Lower carrier volumes may provide increased farm efficiency.}, number={1}, journal={CROP FORAGE & TURFGRASS MANAGEMENT}, author={Mahoney, Denis J. and Jordan, David L. and Hare, Andrew T. and Leon, Ramon G. and Vann, Matthew C. and Burgos, Nilda R. and Jennings, Katherine M.}, year={2019}, month={Oct} } @article{mahoney_jordan_hare_leon_vann_burgos_jennings_2019, title={The Influence of Postemergence Herbicide Timing and Frequency on Weed Control and Soybean Yield}, volume={5}, ISSN={["2374-3832"]}, DOI={10.2134/cftm2019.05.0036}, abstractNote={Core Ideas Optimizing herbicide timing and frequency for weed control in soybean is critical. Two or more postemergence herbicide applications were required in twin- and narrow-row soybean. Herbicide programs generally provided similar soybean yield. More intensive herbicide programs did not reduce economic returns. Understanding optimal herbicide timing and frequency is critical for mitigating weed seed return to the soil seedbank and maximizing crop yields. Research was conducted over 2016–2018 in North Carolina to determine postemergence-only herbicide application timing and the frequency necessary for adequate weed control, soybean [Glycine max (L.) Merr.] yield, and economic return in twin- and narrow-row soybean. Predominant weeds included common ragweed (Ambrosia artemisiifolia L.), large crabgrass [Digitaria sanguinalis (L.) Scop.], Palmer amaranth (Amaranthus palmeri S.Watson), and Texas millet [Urochloa texana (Buckley) R.D.Webster]. Four postemergence timings included early (EPOST), mid-postemergence, late, and very late postemergence (VLPOST) applications in various combinations. An untreated control was included for comparison. Regardless of planting pattern, broadleaf weed control was 9 to 48% higher when herbicides were applied two or more times than with single EPOST or VLPOST-only applications. Generally, two to three applications were needed to provide 100% annual grass control, whereas single applications only provided 71 to 92% control. Applying herbicides increased yield by 21 to 46% when compared with untreated soybean. In treated soybean, yield following the VLPOST treatment was generally lower than under other regimes. Trends for economic return were similar to those of yield. The data illustrate that multiple postemergence applications are needed for adequate weed control and do not adversely affect net returns. Although yields were protected with the EPOST-only treatment, caution must be taken to mitigate returning weed seed to the soil seedbank, as control for this treatment was lower than when herbicides were applied multiple times.}, number={1}, journal={CROP FORAGE & TURFGRASS MANAGEMENT}, author={Mahoney, Denis J. and Jordan, David L. and Hare, Andrew T. and Leon, Ramon G. and Vann, Matthew C. and Burgos, Nilda R. and Jennings, Katherine M.}, year={2019}, month={Nov} } @article{bertucci_jennings_monks_schultheis_louws_jordan_brownie_2018, title={Critical Period for Weed Control in Grafted and Nongrafted Watermelon Grown in Plasticulture}, volume={67}, ISSN={1550-2759}, url={http://dx.doi.org/10.1017/WSC.2018.76}, DOI={10.1017/WSC.2018.76}, abstractNote={AbstractField experiments determined the critical period for weed control (CPWC) in grafted and nongrafted watermelon [Citrullus lanatus(Thumb.) Matsum. & Nakai] grown in plasticulture. Transplant types included ‘Exclamation’ seedless watermelon as the nongrafted control as well as Exclamation grafted onto two interspecific hybrid squash (ISH) rootstocks, ‘Carnivor’ and ‘Kazako’. To simulate weed emergence throughout the season, establishment treatments (EST) consisted of two seedlings each of common purslane (Portulaca oleraceaL.), large crabgrass [Digitaria sanguinalis(L.) Scop.], and yellow nutsedge (Cyperus esculentusL.) transplanted in a 15 by 15 cm square centered on watermelon plants at 0, 2, 3, 4, and 6 wk after watermelon transplanting (WATr) and remained until the final watermelon harvest at 11 WATr. To simulate weed control at different times in the season, removal treatments (REM) consisted of two seedlings of the same weed species transplanted in a 15 by 15 cm square centered on watermelon plants on the same day of watermelon transplanting and allowed to remain until 2, 3, 4, 6, and 11 WATr, at which time they were removed. Season-long weedy and weed-free controls were included for both EST and REM studies in both years. For all transplant types, aboveground biomass of weeds decreased as weed establishment was delayed and increased as weed removal was delayed. The predicted CPWC for nongrafted Exclamation and Carnivor required only a single weed removal between 2.3 and 2.5 WATr and 1.9 and 2.6 WATr, respectively, while predicted CPWC for Kazako rootstock occurred from 0.3 to 2.6 WATr. Our study results suggest that weed control for this mixed population of weeds would be similar between nongrafted Exclamation and Exclamation grafted onto Carnivor. But the observed CPWC of Exclamation grafted onto Kazako suggests that CPWC may vary with specific rootstock–scion combinations.}, number={2}, journal={Weed Science}, publisher={Cambridge University Press (CUP)}, author={Bertucci, Matthew B. and Jennings, Katherine M. and Monks, David W. and Schultheis, Jonathan R. and Louws, Frank J. and Jordan, David L. and Brownie, Cavell}, year={2018}, month={Nov}, pages={221–228} } @article{bertucci_jennings_monks_schultheis_perkins-veazie_louws_jordan_2018, title={Early Season Growth, Yield, and Fruit Quality of Standard and Mini Watermelon Grafted onto Several Commercially Available Cucurbit Rootstocks}, volume={28}, ISSN={["1943-7714"]}, DOI={10.21273/HORTTECH04051-18}, abstractNote={Grafting watermelon (Citrullus lanatus) is a common practice in many parts of the world and has recently received increased interest in the United States. The present study was designed to evaluate early season growth, yield, and fruit quality of watermelon in response to grafting and in the absence of known disease pressure in a fumigated system. Field experiments were conducted using standard and mini watermelons (cv. Exclamation and Extazy, respectively) grafted onto 20 commercially available cucurbit rootstocks representing four species: giant pumpkin (Cucurbita maxima), summer squash (Cucurbita pepo), bottle gourd (Lagenaria siceraria), and interspecific hybrid squash [ISH (C. maxima × Cucurbita moschata)]. Nongrafted ‘Exclamation’ and ‘Extazy’ were included as controls. To determine early season growth, leaf area was measured at 1, 2, and 3 weeks after transplant (WAT). At 1 WAT, nongrafted ‘Exclamation’ produced the smallest leaf area; however, at 3 WAT, nongrafted ‘Exclamation’ produced the largest leaf area in 2015, and no differences were observed in 2016. Leaf area was very similar among rootstocks in the ‘Extazy’ study, with minimal differences observed. Marketable yield included fruit weighing ≥9 and ≥3 lb for ‘Exclamation’ and ‘Extazy’, respectively. In the ‘Exclamation’ study, highest marketable yields were observed in nongrafted ‘Exclamation’, and ‘Exclamation’ grafted to ‘Pelops’, ‘TZ148’, and ‘Coloso’, and lowest marketable yields were observed when using ‘Marvel’ and ‘Kazako’ rootstocks, which produced 47% and 32% of nongrafted ‘Exclamation’ yield, respectively. In the ‘Extazy’ study, the highest marketable yield was observed in nongrafted ‘Extazy’, and ‘Kazako’ produced the lowest yields (48% of nongrafted ‘Extazy’). Fruit quality was determined by measuring fruit acidity (pH), soluble solids concentration (SSC), lycopene content, and flesh firmness from a sample of two fruit from each plot from the initial two harvests of each year. Across both studies, rootstock had no effect on SSC or lycopene content. As reported in previous studies, flesh firmness was increased as a result of grafting, and nongrafted ‘Exclamation’ and ‘Extazy’ had the lowest flesh firmness among standard and mini watermelons, respectively. The present study evaluated two scions with a selection of 20 cucurbit rootstocks and observed no benefits in early season growth, yield, or phytonutrient content. Only three of 20 rootstocks in each study produced marketable yields similar to the nongrafted treatments, and no grafted treatment produced higher yields than nongrafted ‘Exclamation’ or ‘Extazy’. Because grafted seedlings have an associated increase in cost and do not produce increased yields, grafting in these optimized farming systems and using fumigated soils does not offer an advantage in the absence of soilborne pathogens or other stressors that interfere with watermelon production.}, number={4}, journal={HORTTECHNOLOGY}, publisher={American Society for Horticultural Science}, author={Bertucci, Matthew B. and Jennings, Katherine M. and Monks, David W. and Schultheis, Jonathan R. and Perkins-Veazie, Penelope and Louws, Frank J. and Jordan, David L.}, year={2018}, month={Aug}, pages={459–469} } @article{bertucci_jennings_monks_jordan_schultheis_louws_waldschmidt_2018, title={Effect of Bicyclopyrone on Triploid Watermelon in Plasticulture}, volume={32}, ISSN={0890-037X 1550-2740}, url={http://dx.doi.org/10.1017/WET.2018.36}, DOI={10.1017/WET.2018.36}, abstractNote={AbstractField studies were conducted to determine watermelon tolerance and yield response when treated with bicyclopyrone preplant (PREPLANT), POST, and POST-directed (POST-DIR). Treatments consisted of two rates of bicyclopyrone (37.5 and 50 g ai ha–1), fomesafen (175 g ai ha–1), S-metolachlor (802 g ai ha–1), and a nontreated check. Preplant treatments were applied to formed beds 1 d prior to transplanting and included bicyclopyrone (37.5 and 50 g ha–1) and fomesafen (175 g ha–1), and new polyethylene mulch was subsequently laid above treated beds. POST and POST-DIR treatments were applied 14 ± 1 d after watermelon transplanting and included bicyclopyrone (37.5 and 50 g ha–1) POST and POST-DIR, and S-metolachlor (802 g ai ha–1) POST-DIR. POST-DIR treatments were applied to row middles, ensuring that no herbicide contacted watermelon vines or polyethylene mulch. At 2 wk after transplanting (WAT), 15% foliar bleaching was observed in watermelon treated with bicyclopyrone (50 g ha–1) PRE. At 3 WAT, bicyclopyrone (37.5 and 50 g ha–1) POST caused 16% and 17% foliar bleaching and 8% and 9% crop stunting, respectively. At 4 WAT, initial injury had subsided and bicyclopyrone (37.5 and 50 g ha–1) POST caused 4% and 4% foliar bleaching and 4% and 8% crop stunting, respectively. No symptoms of bleaching or stunting were observed at 6- and 8-WAT ratings. Watermelon total yield, marketable yield, total fruit number, marketable fruit number, and average fruit size were unaffected by herbicide treatments. Therefore, registration of bicyclopyrone (37.5 and 50 g ha–1) PREPLANT, POST, and POST-DIR would offer watermelon producers a safe herbicide option and a novel mode of action for weed management.}, number={4}, journal={Weed Technology}, publisher={Cambridge University Press (CUP)}, author={Bertucci, Matthew B. and Jennings, Katherine M. and Monks, David W. and Jordan, David L. and Schultheis, Jonathan R. and Louws, Frank J. and Waldschmidt, Matthew D.}, year={2018}, month={Jun}, pages={439–443} } @article{seth carley_jordan_dharmasri_shew_sutton_brandenburg_2018, title={Examples of Differences in Red Edge Reflectance and Normalized Difference Vegetative Index caused by Stress in Peanut}, volume={4}, ISSN={["2374-3832"]}, DOI={10.2134/cftm2018.06.0042}, abstractNote={Core Ideas Canopy reflectance is a potential tool for peanut management. Lesions caused by disease decreased red edge reflectance and NDVI. Leaves expressing nitrogen deficiency and drought stress decreased red edge reflectance and NDVI. }, number={1}, journal={Crop, Forage & Turfgrass Management}, author={Seth Carley, D. and Jordan, D.L. and Dharmasri, C.L. and Shew, B.B. and Sutton, T.B. and Brandenburg, R.L.}, year={2018}, month={Oct}, pages={1–2} } @article{nigam_jordan_janila_2018, title={Improving cultivation of groundnuts}, volume={36}, ISBN={["978-1-78676-140-8"]}, ISSN={["2059-6944"]}, DOI={10.19103/AS.2017.0023.27}, abstractNote={Groundnut (also known as peanut) (Arachis hypogaea L.), a native of South America, has often been referred to as an unpredictable legume in the past (Gregory and Gregory, 1979; Hammons, 1994). The genus Arachis contains 81 described species, categorized into nine taxonomic sections, and includes both diploids and tetraploids belonging to either annual or perennial type. The classification is based on morphology, geographical distribution and cross-compatibility among the species (Valls and Simpson, 2005). The only cultivated groundnut, Arachis hypogaea L., is further divided into two sub-species ‘hypogaea’ and ‘fastigata’ based on the branching pattern and the distribution of vegetative and reproductive axes. Although it has been known to humankind for many centuries, its commercial cultivation started only in early 1900, when it began receiving research attention...}, journal={ACHIEVING SUSTAINABLE CULTIVATION OF GRAIN LEGUMES, VOL 2: IMPROVING CULTIVATION OF PARTICULAR GRAIN LEGUMES}, author={Nigam, S. N. and Jordan, D. L. and Janila, P.}, year={2018}, pages={155–179} } @article{jordan_johnson_hare_anco_chapin_thomas_monfort_balota_2018, title={Influence of Inoculation with Bradyrhizobia and Nitrogen Rate on Yield and Estimated Economic Return of Virginia Market-Type Peanut}, volume={4}, ISSN={["2374-3832"]}, DOI={10.2134/cftm2018.01.0002}, abstractNote={Core Ideas Bradyrhizobia inoculant increases peanut yield in new peanut fields and in fields with a recent history of peanut. Applied nitrogen is less effective than inoculation with Bradyrhizobia in new peanut fields. Return on investment from Bradyrhizobia inoculant occurs regardless of field history relative to peanut production. Adequate nitrogen (N) fixation by peanut (Arachis hypogaea L.) is essential to optimize yield. In replicated trials in North Carolina, South Carolina, and Virginia from 1998–2017, commercially available in‐furrow liquid or granular inoculant increased yield from 3460 to 4660 lb/acre in new peanut fields (52 trials) and 4280 to 4450 lb/acre in fields with a previous history of peanut plantings within the past 4 years (43 trials). The increase in economic value from inoculation treatment ($8/acre) at a peanut price of $535/ton was $318/acre and $41/acre in fields with these respective histories. In a second experiment, replicated trials were conducted from 2007–2017 in fields without a history of peanut production or fields not rotated to peanut within at least the past 20 years. Economic return based on peanut prices described previously was determined to reflect cost of N applied as ammonium sulfate ($0.28/lb ammonium sulfate) as a single application 45 to 60 days after planting when canopy foliage began to express N deficiency. A linear or quadratic response to rates of 0, 60, 90, 120, and 150 lb N/acre was noted in five trials with no response observed in the remaining four trials. When these experiments were included with five other experiments where non‐inoculated and inoculated controls were compared with one rate only (120 lb N/acre), yield and economic return were greater for inoculated peanut compared with peanut receiving N or the non‐inoculated and non‐fertilized control. Nitrogen increased peanut yield and economic return compared with the non‐fertilized control. Results from these experiments underscore the value of inoculation with Bradyrhizobia at planting regardless of field history and the limitations of applied N to correct N deficiencies in peanut.}, number={1}, journal={CROP FORAGE & TURFGRASS MANAGEMENT}, author={Jordan, David L. and Johnson, P. Dewayne and Hare, Andrew T. and Anco, Dan and Chapin, Jay and Thomas, James and Monfort, Scott and Balota, Maria}, year={2018}, month={Oct} } @article{bertucci_jennings_monks_schultheis_louws_jordan_2018, title={Interference of Palmer amaranth (Amaranthus palmeri) Density in Grafted and Nongrafted Watermelon}, volume={67}, ISSN={1550-2759}, url={http://dx.doi.org/10.1017/WSC.2018.77}, DOI={10.1017/WSC.2018.77}, abstractNote={AbstractWatermelon [Citrullus lanatus(Thunb.) Matsum & Nakai] grafting is commonly used for management of diseases caused by soilborne pathogens; however, little research exists describing the effect of grafting on the weed-competitive ability of watermelon. Field experiments determined the response in yield, fruit number, and fruit quality of grafted and nongrafted watermelon exposed to increasing densities of Palmer amaranth (Amaranthus palmeriS. Watson). Grafting treatments included ‘Exclamation’ triploid (seedless) watermelon grafted on two interspecific hybrid squash rootstocks ‘Carnivor’ and ‘Kazako’, with nongrafted Exclamation as the control. Weed treatments includedA. palmeriat densities of 1, 2, 3, and 4A. palmeriplants per watermelon planting hole (0.76-m row) and a weed-free control. IncreasingA. palmeridensities caused significant reductions (P <0.05) in marketable watermelon yield and marketable fruit number. Watermelon yield reduction was described by a rectangular hyperbola model, and 4A. palmeriplants planting hole−1reduced marketable yield 41%, 38%, and 65% for Exclamation, Carnivor, and Kazako, respectively. Neither grafting treatment norA. palmeridensity had a biologically meaningful effect on soluble solids content or on the incidence of hollow heart in watermelon fruit.Amaranthus palmeriseed and biomass production was similar across weed population densities, but seed number per femaleA. palmeridecreased according to a two-parameter exponential decay equation. Thus, increasing weed population densities resulted in increased intraspecific competition amongA. palmeriplants. While grafting may offer benefits for disease resistance, no benefits regarding weed-competitive ability were observed, and a consistent yield penalty was associated with grafting, even in weed-free treatments.}, number={2}, journal={Weed Science}, publisher={Cambridge University Press (CUP)}, author={Bertucci, Matthew B. and Jennings, Katherine M. and Monks, David W. and Schultheis, Jonathan R. and Louws, Frank J. and Jordan, David L.}, year={2018}, month={Dec}, pages={229–238} } @article{jordan_brandenburg_payne_hoisington_magnan_rhoads_abudulai_adhikari_chen_akromah_et al._2018, title={Preventing mycotoxin contamination in groundnut cultivation}, volume={36}, ISBN={["978-1-78676-140-8"]}, ISSN={["2059-6944"]}, DOI={10.19103/AS.2017.0023.28}, journal={ACHIEVING SUSTAINABLE CULTIVATION OF GRAIN LEGUMES, VOL 2: IMPROVING CULTIVATION OF PARTICULAR GRAIN LEGUMES}, author={Jordan, David and Brandenburg, Rick and Payne, Gary and Hoisington, David and Magnan, Nick and Rhoads, James and Abudulai, Mumuni and Adhikari, Koushik and Chen, Jinru and Akromah, Richard and et al.}, year={2018}, pages={181–211} } @article{jordan_hare_roberson_shew_brandenburg_anco_balota_mehl_taylor_2018, title={Summary of Variables Associated with Application of Plant Protection Products in Peanut}, volume={4}, ISSN={["2374-3832"]}, DOI={10.2134/cftm2018.05.0034}, abstractNote={Core Ideas Peanut acreage was positively correlated with tank size, boom width, and ground speed. Peanut acreage was not correlated with peanut yield, spray volume, and spray pressure. Co‐applying three or more products in the same tank was common among growers. Flat‐fan nozzles were the most commonly used spray nozzles among peanut growers. Growers spend approximately 18% of their time applying crop protection products. }, number={1}, journal={CROP FORAGE & TURFGRASS MANAGEMENT}, author={Jordan, David L. and Hare, Andrew T. and Roberson, Gary T. and Shew, Barbara B. and Brandenburg, Rick L. and Anco, Dan and Balota, Maria and Mehl, Hillary and Taylor, Sally}, year={2018}, month={Oct} } @article{jordan_york_2018, title={Weed Species Richness and Density following Repeated Use of Glyphosate in Four Fields in North Carolina}, volume={4}, ISSN={["2374-3832"]}, DOI={10.2134/cftm2017.12.0089}, abstractNote={Core Ideas Long‐term use of glyphosate can reduce weed species richness. Long‐term use of glyphosate can select for resistant biotypes. Impact of continuous use of glyphosate depends on weed species. }, number={1}, journal={CROP FORAGE & TURFGRASS MANAGEMENT}, author={Jordan, David L. and York, Alan C.}, year={2018}, month={Apr} } @article{chaudhari_jennings_monks_jordan_gunter_louws_2017, title={Absorption, Translocation, and Metabolism of 14C-Halosulfuron in Grafted Eggplant and Tomato}, volume={31}, ISSN={0890-037X 1550-2740}, url={http://dx.doi.org/10.1017/WET.2017.65}, DOI={10.1017/WET.2017.65}, abstractNote={Grafted plants are a combination of two different interspecific or intraspecific scion and rootstock. Determination of herbicidal selectivity of the grafted plant is critical given their increased use in vegetable production. Differential absorption, translocation, and metabolism play an important role in herbicide selectivity of plant species because these processes affect the herbicide amount delivered to the site of action. Therefore, experiments were conducted to determine absorption, translocation, and metabolism of halosulfuron in grafted and non-grafted tomato and eggplant. Transplant type included non-grafted tomato cultivar Amelia, non-grafted eggplant cultivar Santana, Amelia scion grafted onto Maxifort tomato rootstock (A-Maxifort) and Santana scion grafted onto Maxifort rootstock (S-Maxifort). Plants were treated POST with commercially formulated halosulfuron at 39 g ai ha-1followed by14C-halosulfuron under controlled laboratory conditions. Amount of14C-halosufuron was quantified in leaf wash, treated leaf, scion shoot, rootstock shoot, and root at 6, 12, 24, 48, and 96 h after treatment (HAT) using liquid scintillation spectrometry. No differences were observed between transplant types with regard to absorption and translocation of14C-halosulfuron. Absorption of14C-halosulfuron increased with time, reaching 10 and 74% of applied at 6 and 96 HAT, respectively. Translocation of14C-halosulfuron was limited to the treated leaf, which reached maximum (66% of applied) at 96 HAT, whereas minimal (<4% of applied) translocation occurred in scion shoot, rootstock shoot, and root. Tomato plants metabolized halosulfuron faster compared to eggplant regardless of grafting. Of the total amount of14C-halosulfuron absorbed into the plant, 9 to 14% remained in the form of the parent compound in tomato compared with 25 to 26% in eggplant at 48 HAT. These results indicate that grafting did not affect absorption, translocation, and metabolism of POST halosulfuron in tomato and eggplant.}, number={6}, journal={Weed Technology}, publisher={Cambridge University Press (CUP)}, author={Chaudhari, Sushila and Jennings, Katherine M. and Monks, David W. and Jordan, David L. and Gunter, Christopher C. and Louws, Frank J.}, year={2017}, month={Sep}, pages={908–914} } @article{vann_fisher_wells_jordan_heitman_2017, title={Alternative Ridging Practices for Flue-Cured Tobacco Production in North Carolina}, volume={3}, ISSN={2374-3832}, url={http://dx.doi.org/10.2134/cftm2017.02.0016}, DOI={10.2134/cftm2017.02.0016}, abstractNote={Core Ideas Alternative ridging methods could prove beneficial for tobacco producers. Conservation tillage efforts have demonstrated little success. Fine‐textured soils will require special management considerations. Soil resistance is considered to be a limiting production factor. Coarse‐textured soils appear to be better suited than fine‐textured soils. With increasing farm size and the necessity for timely field preparation, flue‐cured tobacco (Nicotiana tabacum L.) producers in North Carolina would benefit from alternatives to current ridging practices. Research was conducted in 2012 and 2013 to evaluate the effects of differing ridging methods on soil physical properties and the growth and development of flue‐cured tobacco. In each environment, two alternative ridging methods were compared with the grower standard of spring ridging (SR): fall ridging (FR) and rotary ridging (RR) in the Piedmont, and FR and no ridging (NR) in the Coastal Plain. In the Piedmont, FR reduced leaf yield and value when compared with RR and SR systems. Reduced yield and value were a result of high soil resistance that inhibited plant growth. In the Coastal Plain, treatments imposed did not affect the soil physical properties or tobacco yield and quality. Results indicate that FR and NR systems are acceptable alternative ridging methods for the production of flue‐cured tobacco in the sandy Coastal Plain growing region. Alternatively, FR should not be used in the Piedmont growing region due to the fine soil texture that is prone to high resistance.}, number={1}, journal={Crop, Forage & Turfgrass Management}, publisher={Wiley}, author={Vann, Matthew C. and Fisher, Loren R. and Wells, Randy and Jordan, David L. and Heitman, Joshua L.}, year={2017}, month={Jun}, pages={cftm2017.02.0016} } @article{chaudhari_jordan_york_jennings_cahoon_chandi_inman_2017, title={Biology and Management of Glyphosate-Resistant and Glyphosate-Susceptible Palmer Amaranth (Amaranthus palmeri) Phenotypes from a Segregating Population}, volume={65}, ISSN={1550-2759}, url={http://dx.doi.org/10.1017/WSC.2017.52}, DOI={10.1017/WSC.2017.52}, abstractNote={Palmer amaranth is the most economically damaging glyphosate-resistant (GR) weed in the southern United States. An understanding of the basic biology, including relative growth and competitiveness of GR and glyphosate-susceptible (GS) Palmer amaranth phenotypes from a segregating population collected from the same geographical location, may yield information helpful in the management of resistant populations. A segregating population of Palmer amaranth collected in North Carolina during 2010 was used as a plant source for both GR and GS traits. Research was conducted in the greenhouse to compare the following: level of resistance and shikimate accumulation in GR and GS phenotypes following glyphosate application; interference from GR and GS phenotypes on early-season vegetative growth of corn, cotton, and peanut; effect of various durations of imposed drought stress on GR and GS phenotypes; and response of GR and GS phenotypes to POST-applied herbicides. The GR50(glyphosate rate providing 50% reduction in shoot dry biomass) was 17 times greater with the GR phenotype compared with the GS phenotype. Shikimate accumulated in both GR and GS phenotypes following glyphosate application, but greater concentrations were found in GS plants. The GR and GS phenotypes responded similarly when subjected to drought stress; grown with corn, cotton, and peanut; or treated with 2,4-D, atrazine, dicamba, fomesafen, glufosinate, paraquat, tembotrione, and thifensulfuron. These results indicate that in the absence of glyphosate selection pressure, resistance to glyphosate does not influence the growth and competitiveness of GR and GS Palmer amaranth phenotypes collected from the same geographical location.}, number={6}, journal={Weed Science}, publisher={Cambridge University Press (CUP)}, author={Chaudhari, Sushila and Jordan, David L. and York, Alan C. and Jennings, Katherine M. and Cahoon, Charles W. and Chandi, Aman and Inman, Matthew D.}, year={2017}, month={Aug}, pages={755–768} } @article{chaudhari_jordan_york_jennings_cahoon_chandi_inman_2017, title={Biology and management of Glyphosate-resistant and Glyphosate-susceptible Palmer Amaranth (&ITAmaranthus&IT &ITpalmeri&IT) phenotypes from a segregating population}, volume={65}, number={6}, journal={Weed Science}, author={Chaudhari, S. and Jordan, D. L. and York, A. C. and Jennings, K. M. and Cahoon, C. W. and Chandi, A. and Inman, M. D.}, year={2017}, pages={755–768} } @article{abudulai_naab_seini_dzomeku_boote_brandenburg_jordan_2018, title={Peanut (Arachis hypogaea) response to weed and disease management in northern Ghana}, volume={64}, ISSN={["1366-5863"]}, DOI={10.1080/09670874.2017.1371806}, abstractNote={ABSTRACT Weeds and diseases can reduce peanut (Arachis hypogaea L.) yield or increase cost of production to maintain acceptable yield. While herbicides and fungicides have limited availability in many areas of Ghana and currently are too expensive for resource-poor farmers, control by these pesticides can have a major positive impact on peanut yield. Field experiments were conducted during the rainy seasons of 2009 and 2010 in northern Ghana to determine the effects of herbicide and hand weeding in combination with fungicides on pest management and peanut yield. Peanut pod yield was often more highly correlated with disease severity and canopy defoliation resulting from early leaf spot (caused by Cercospora arachidicola Hori) and late leaf spot (caused by Cercosporidium personatum (Berk. & M.A. Curtis) Deighton) than weed biomass. In some instances, less disease and canopy defoliation were observed when weeds were not controlled effectively compared with increased weed management through hand weeding or herbicide. Two hand weedings or applying pendimethalin preemergence with one hand weeding in combination with 4 applications of triadimefon and chlorothalonil resulted in the lowest weed density and canopy defoliation and often resulted in the highest peanut yield.}, number={3}, journal={INTERNATIONAL JOURNAL OF PEST MANAGEMENT}, author={Abudulai, Mumuni and Naab, Jesse and Seini, Shaibu Seidu and Dzomeku, Israel and Boote, Kenneth and Brandenburg, Rick and Jordan, David}, year={2018}, pages={204–209} } @article{mulvaney_balkcom_wood_jordan_2017, title={Peanut Residue Carbon and Nitrogen Mineralization under Simulated Conventional and Conservation Tillage}, volume={109}, ISSN={["1435-0645"]}, DOI={10.2134/agronj2016.04.0190}, abstractNote={Core Ideas Recommendations of 22 to 67 kg N ha−1 credit after peanut are not substantiated. Decomposition of peanut residue in North Carolina and Alabama fit double exponential decay equations. Nitrogen credit to wheat was 14 to 24 kg N ha−1, but to cotton was 2 to 10 kg N ha−1. Nitrogen credits differ by location and placement of residue. Nitrogen credits should be specified to which crop they are applied. Residue management is an important aspect of cropping systems. Availability of plant residue N to succeeding crops depends on N mineralization rates. Cooperative Extension currently recommends 22 to 67 kg N ha−1 credit to subsequent crops following peanut (Arachis hypogaea L.), but these recommendations are not supported in the literature, nor do they specify if the credit is applied to a subsequent winter or spring crop. The objective of this study was to assess N release rates from residues of three peanut cultivars (NC V‐11, GA 02‐C, and ANorden) at two placements (surface and 10‐cm deep) and two locations representing northern and southern extremes of U.S. commercial peanut production (North Carolina and Alabama). Litterbags containing the equivalent of 3.5 Mg ha−1 were placed in a completely randomized design at both locations with four replications and retrieved periodically up to 335 d after application. Results were fit to single or double exponential decay models. Based on empirical models, the N credit to a subsequent winter wheat (Triticum aestivum L.) crop was estimated at 14 to 19 kg N ha−1 when peanut residues were buried after harvest, and 19 to 24 kg N ha−1 when on the soil surface. When N credits were applied to a subsequent cotton (Gossypium hirsutum L.) crop, they were reduced to 2 to 9 kg N ha−1 (buried) and 6 to 10 kg N ha−1 (surface). Current recommendations are higher than the results obtained in this study suggest and warrant re‐examination.}, number={2}, journal={AGRONOMY JOURNAL}, author={Mulvaney, Michael J. and Balkcom, Kipling S. and Wood, C. Wes and Jordan, David}, year={2017}, pages={696–705} } @article{chaudhari_jennings_monks_jordan_gunter_louws_2017, title={Response of Drought-Stressed Grafted and Nongrafted Tomato to Postemergence Metribuzin}, volume={31}, ISSN={["1550-2740"]}, DOI={10.1017/wet.2017.12}, abstractNote={Tomato grafting is practiced worldwide as an innovative approach to manage stress from drought, waterlogging, insects, and diseases. Metribuzin is a commonly used herbicide in tomato but has potential to cause injury after application if plants are under stress. The influence of metribuzin on grafted tomato under drought-stress has not been studied. Greenhouse experiments were conducted in Raleigh, NC to determine the tolerance of drought-stressed grafted and non-grafted tomato to metribuzin. The tomato cultivar ‘Amelia’ was used as the scion in grafted tomato, and for the non-grafted control. Two hybrid tomato ‘Beaufort’ and ‘Maxifort’ were used as rootstocks for grafted plants. Drought-stress treatments included: no drought-stress; 3 d of drought-stress before metribuzin application with no drought-stress after application (3 d DSB); and 3 d of drought-stress before metribuzin application with 3 d of drought-stress after application (3 d DSBA). Metribuzin was applied at 550 g ai ha−1. No difference in injury from metribuzin was observed in grafted and non-grafted plants. However, at 7 and 14 d after metribuzin treatment (DMT), less injury was observed on tomato in the 3 d DSBA treatment (5 and 2% injury, respectively) than on plants in the 3 d DSB treatment (15 and 8% injury, respectively) or those that were never drought-stressed (18 and 11% injury, respectively). Photosynthesis and stomatal conductance measured prior to metribuzin application were reduced similarly in grafted and non-grafted tomato subjected to drought-stress. Photosynthesis and stomatal conductance of grafted and non-grafted tomato at 7 DMT was not different among drought-stress treatments or metribuzin treatments. Grafted and non-grafted tomato plants under drought-stress exhibit similar tolerance to metribuzin. The risk of metribuzin injury to grafted tomato under drought-stress is similar to non-grafted tomato.}, number={3}, journal={WEED TECHNOLOGY}, author={Chaudhari, Sushila and Jennings, Katherine M. and Monks, David W. and Jordan, David L. and Gunter, Christopher C. and Louws, Frank J.}, year={2017}, pages={447–454} } @article{akoto_klu_lamptey_asibuo_davis_phillips_jordan_rhoads_hoistington_chen_2017, title={Use of peanut meal as a model matrix to study the effect of composting on aflatoxin decontamination}, volume={10}, ISSN={["1875-0796"]}, DOI={10.3920/wmj2016.2155}, abstractNote={In developing countries, aflatoxin-contaminated peanut wastes are often used as mulching materials or soil amendments, which introduce aflatoxins and aflatoxin-producing mould into subsequent farming seasons. This research evaluated the effectiveness of composting as a means of aflatoxin decontamination using highly-contaminated peanut meal as a model matrix at 40 °C for 6 w. The composting methods caused 72.2-154.9 (41.9-75.1%), 7.4-17.6 (37.9-72.0%), 1.2-6.9 (77.1-100.0%), or 0.0-2.1 (0.0-100.0%) μg/kg reduction in the levels of aflatoxin B1, B2, G1 and G2 in peanut meal, respectively. Aspergillus flavus and Aspergillus parasiticus counts and total mould counts decreased from 103-105 to <10 colony forming units/g. Composting time and the type of starters used significantly influenced aflatoxin content, while the presence of accelerator did not affect aflatoxin levels. The highest level of toxin decontamination occurred in the first week when compost temperature and ammonia concentration were high. Micronutrient contents of resulting composts were within the accepted range for fertilisers, except for calcium. Heavy metal content was below the maximum allowable levels except nickel in one of the samples. Aflatoxin reduction was also observed in an up-scale experiment using contaminated agriculture waste as raw materials. Results suggest that composting could be employed to decontaminate aflatoxin-containing agricultural waste in developing countries.}, number={2}, journal={WORLD MYCOTOXIN JOURNAL}, author={Akoto, E. Y. and Klu, Y. A. K. and Lamptey, M. and Asibuo, J. Y. and Davis, J. and Phillips, R. and Jordan, D. and Rhoads, J. and Hoistington, D. and Chen, J.}, year={2017}, pages={131–141} } @article{chaudhari_jennings_monks_jordan_gunter_mcgowen_louws_2016, title={Critical Period for Weed Control in Grafted and Nongrafted Fresh Market Tomato}, volume={64}, ISSN={["1550-2759"]}, DOI={10.1614/ws-d-15-00049.1}, abstractNote={Field experiments were conducted to determine the critical period for weed control (CPWC) in nongrafted ‘Amelia’ and Amelia grafted onto ‘Maxifort’ tomato rootstock grown in plasticulture. The establishment treatments (EST) consisted of two seedlings each of common purslane, large crabgrass, and yellow nutsedge transplanted at 1, 2, 3, 4, 5, 6, and 12 wk after tomato transplanting (WAT) and remained until tomato harvest to simulate weeds emerging at different times. The removal treatments (REM) consisted of the same weeds transplanted on the day of tomato transplanting and removed at 2, 3, 4, 5, 6, 8, and 12 WAT to simulate weeds controlled at different times. The beginning and end of the CPWC, based on a 5% yield loss of marketable tomato, was determined by fitting log-logistic and Gompertz models to the relative yield data representing REM and EST, respectively. In both grafted and nongrafted tomato, plant aboveground dry biomass increased as establishment of weeds was delayed and tomato plant biomass decreased when removal of weeds was delayed. For a given time of weed removal and establishment, grafted tomato plants produced higher biomass than nongrafted. The delay in establishment and removal of weeds resulted in weed biomass decrease and increase of the same magnitude, respectively, regardless of transplant type. The predicted CPWC was from 2.2 to 4.5 WAT in grafted tomato and from 3.3 to 5.8 WAT in nongrafted tomato. The length (2.3 or 2.5 wk) of the CPWC in fresh market tomato was not affected by grafting; however, the CPWC management began and ended 1 wk earlier in grafted tomato than in nongrafted tomato.}, number={3}, journal={WEED SCIENCE}, author={Chaudhari, Sushila and Jennings, Katherine M. and Monks, David W. and Jordan, David L. and Gunter, Christopher C. and McGowen, Samuel J. and Louws, Frank J.}, year={2016}, pages={523–530} } @article{riar_carley_zhang_schroeder-moreno_jordan_webster_rufty_2016, title={Environmental Influences on Growth and Reproduction of Invasive Commelina benghalensis}, volume={2016}, ISSN={1687-8159 1687-8167}, url={http://dx.doi.org/10.1155/2016/5679249}, DOI={10.1155/2016/5679249}, abstractNote={Commelina benghalensis(Benghal dayflower) is a noxious weed that is invading agricultural systems in the southeastern United States. We investigated the influences of nutrition, light, and photoperiod on growth and reproductive output ofC. benghalensis. In the first experimental series, plants were grown under high or low soil nutrition combined with either full light or simulated shade. Lowered nutrition strongly inhibited vegetative growth and aboveground spathe production. Similar but smaller effects were exerted by a 50% reduction in light, simulating conditions within a developing canopy. In the second series of experiments,C. benghalensisplants were exposed to different photoperiod conditions that produced short- and long-day plants growing in similar photosynthetic periods. A short-day photoperiod decreased time to flowering by several days and led to a 40 to 60% reduction in vegetative growth, but reproduction above and below ground was unchanged. Collectively, the results indicate that (1) fertility management in highly weathered soils may strongly constrain competitiveness ofC. benghalensis; (2) shorter photoperiods will limit vegetative competitiveness later in the growing seasons of most crops; and (3) the high degree of reproductive plasticity and output possessed byC. benghalensiswill likely cause continual persistence problems in agricultural fields.}, journal={International Journal of Agronomy}, publisher={Hindawi Limited}, author={Riar, Mandeep K. and Carley, Danesha S. and Zhang, Chenxi and Schroeder-Moreno, Michelle S. and Jordan, David L. and Webster, Theodore M. and Rufty, Thomas W.}, year={2016}, pages={1–9} } @article{foote_edmisten_wells_collins_roberson_jordan_fisher_2016, title={Influence of nitrogen and mepiquat chloride on cotton canopy reflectance measurements}, volume={20}, number={1}, journal={Journal of Cotton Science}, author={Foote, W. and Edmisten, K. and Wells, R. and Collins, G. and Roberson, G. and Jordan, D. and Fisher, L.}, year={2016}, pages={1–7} } @article{braswell_cahoon_seagroves_jordan_york_2016, title={Integrating fluridone into a glufosinate-based program for Palmer amaranth control in cotton}, volume={20}, number={4}, journal={Journal of Cotton Science}, author={Braswell, L. R. and Cahoon, C. W. and Seagroves, R. W. and Jordan, D. L. and York, A. C.}, year={2016}, pages={394–402} } @article{inman_jordan_york_jennings_monks_everman_bollman_fowler_cole_soteres_et al._2016, title={Long-Term Management of Palmer Amaranth (Amaranthus palmeri) in Dicamba-Tolerant Cotton}, volume={64}, ISSN={["1550-2759"]}, DOI={10.1614/ws-d-15-00058.1}, abstractNote={Research was conducted from 2011 to 2014 to determine weed population dynamics and frequency of glyphosate-resistant (GR) Palmer amaranth with herbicide programs consisting of glyphosate, dicamba, and residual herbicides in dicamba-tolerant cotton. Five treatments were maintained in the same plots over the duration of the experiment: three sequential POST applications of glyphosate with or without pendimethalin plus diuron PRE; three sequential POST applications of glyphosate plus dicamba with and without the PRE herbicides; and a POST application of glyphosate plus dicamba plus acetochlor followed by one or two POST applications of glyphosate plus dicamba without PRE herbicides. Additional treatments included alternating years with three sequential POST applications of glyphosate only and glyphosate plus dicamba POST with and without PRE herbicides. The greatest population of Palmer amaranth was observed when glyphosate was the only POST herbicide throughout the experiment. Although diuron plus pendimethalin PRE in a program with only glyphosate POST improved control during the first 2 yr, these herbicides were ineffective by the final 2 yr on the basis of weed counts from soil cores. The lowest population of Palmer amaranth was observed when glyphosate plus dicamba were applied regardless of PRE herbicides or inclusion of acetochlor POST. Frequency of GR Palmer amaranth was 8% or less when the experiment was initiated. Frequency of GR Palmer amaranth varied by herbicide program during 2012 but was similar among all herbicide programs in 2013 and 2014. Similar frequency of GR Palmer amaranth across all treatments at the end of the experiment most likely resulted from pollen movement from Palmer amaranth treated with glyphosate only to any surviving female plants regardless of PRE or POST treatment. These data suggest that GR Palmer amaranth can be controlled by dicamba and that dicamba is an effective alternative mode of action to glyphosate in fields where GR Palmer amaranth exists.}, number={1}, journal={WEED SCIENCE}, author={Inman, M. D. and Jordan, D. L. and York, A. C. and Jennings, Katherine and Monks, D. W. and Everman, W. J. and Bollman, S. L. and Fowler, J. T. and Cole, R. M. and Soteres, J. K. and et al.}, year={2016}, pages={161–169} } @article{soltani_dille_burke_everman_vangessel_davis_sikkema_2016, title={Potential Corn Yield Losses from Weeds in North America}, volume={30}, ISSN={["1550-2740"]}, DOI={10.1614/wt-d-16-00046.1}, abstractNote={Crop losses from weed interference have a significant effect on net returns for producers. Herein, potential corn yield loss because of weed interference across the primary corn-producing regions of the United States and Canada are documented. Yield-loss estimates were determined from comparative, quantitative observations of corn yields between nontreated and treatments providing greater than 95% weed control in studies conducted from 2007 to 2013. Researchers from each state and province provided data from replicated, small-plot studies from at least 3 and up to 10 individual comparisons per year, which were then averaged within a year, and then averaged over the seven years. The resulting percent yield-loss values were used to determine potential total corn yield loss in t ha−1 and bu acre−1 based on average corn yield for each state or province, as well as corn commodity price for each year as summarized by USDA-NASS (2014) and Statistics Canada (2015). Averaged across the seven years, weed interference in corn in the United States and Canada caused an average of 50% yield loss, which equates to a loss of 148 million tonnes of corn valued at over U.S.$26.7 billion annually.}, number={4}, journal={WEED TECHNOLOGY}, author={Soltani, Nader and Dille, J. Anita and Burke, Ian C. and Everman, Wesley J. and VanGessel, Mark J. and Davis, Vince M. and Sikkema, Peter H.}, year={2016}, pages={979–984} } @article{chaudhari_jennings_monks_jordan_gunter_basinger_louws_2016, title={Response of Eggplant (Solanum melongena) Grafted onto Tomato (Solanum lycopersicum) Rootstock to Herbicides}, volume={30}, ISSN={["1550-2740"]}, DOI={10.1614/wt-d-15-00079.1}, abstractNote={Tomato rootstocks have been successfully used for eggplant production. However, the safety of herbicides registered in tomato has not been tested on grafted eggplant, which is a combination of tomato rootstock and eggplant scion. Greenhouse and field experiments were conducted to determine response of grafted eggplant on tomato rootstock to napropamide, metribuzin, halosulfuron, trifluralin,S-metolachlor, and fomesafen herbicides. In greenhouse experiments, herbicide treatments included pretransplantS-metolachlor (400 and 800 g ai ha−1), pre- or posttransplant metribuzin (140 and 280 g ai ha−1), and posttransplant halosulfuron (18 and 36 g ai ha−1). In field experiments, herbicide treatments included pretransplant fomesafen (280 and 420 g ai ha−1), halosulfuron (39 and 52 g ha−1), metribuzin (280 and 550 g ha−1), napropamide (1,120 and 2,240 g ai ha−1),S-metolachlor (800 and 1,060 g ha−1), and trifluralin (560 and 840 g ai ha−1). The eggplant cultivar ‘Santana' was used as the scion and nongrafted control, and two hybrid tomatoes ‘RST-04−106-T' and ‘Maxifort' were used as rootstocks for grafted plants. In both greenhouse and field experiments, there was no difference between grafted and nongrafted eggplant in terms of injury caused by herbicides. Metribuzin posttransplant at 140 and 280 g ha−1caused 94 and 100% injury to grafted and nongrafted eggplant 4 wk after treatment. In field experiments, pretransplant fomesafen, napropamide,S-metolachlor, and trifluralin caused less than 10% injury and no yield reduction in grafted and nongrafted eggplant. However, metribuzin caused injury and yield reduction in both grafted and nongrafted eggplant. Metribuzin at 550 g ha−1caused 60 and 81% plant stand loss in 2013 and 2014, respectively. Halosulfuron reduced yield 24% in both grafted and nongrafted eggplant compared to nontreated control in 2013 but did not reduce yield in 2014. The pretransplantS-metolachlor, napropamide, fomesafen, and trifluralin are safe to use on eggplant grafted onto tomato rootstock, and will be a valuable addition to the toolkit of eggplant growers.}, number={1}, journal={WEED TECHNOLOGY}, author={Chaudhari, Sushila and Jennings, Katherine M. and Monks, David W. and Jordan, David L. and Gunter, Christopher C. and Basinger, Nicholas T. and Louws, Frank J.}, year={2016}, pages={207–216} } @article{gibson_young_owen_gage_matthews_jordan_shaw_weller_wilson_2016, title={Benchmark study on glyphosate-resistant cropping systems in the United States. Part 7: Effects of weed management strategy (grower practices versus academic recommendations) on the weed soil seedbank over 6 years}, volume={72}, ISSN={["1526-4998"]}, DOI={10.1002/ps.4039}, abstractNote={AbstractBACKGROUNDShifts in weed species composition and richness resulting from near‐exclusive reliance on herbicides in glyphosate‐resistant (GR) cropping systems has necessitated the implementation of alternative weed management tactics to reduce selection pressures of herbicides. We contrasted the response of the weed soil seedbank to effects of weed management strategy, comparing grower practices with academic recommendations for best management practices (BMPs) over 6 years and across five weed hardiness zones in the US Midwest at sites subject to GR cropping systems.RESULTSTotal weed population density and species richness varied according to cropping system, location and prior year's crop, but less so to weed management strategy. The seedbank population density for 11 of the 14 most frequent weed species was affected by weed management strategy either alone or in an interaction with hardiness zone or year, or both. In only 29% of comparisons was weed population density lower following academic recommendations, and this depended upon prior crop and cropping system. The population density of high‐risk weed species was reduced by academic recommendations, but only in two of six years and under continuous GR maize. Overall, the weed population density was decreasing in field halves subject to the BMPs in the academic recommendations relative to grower practices.CONCLUSIONThe soil seedbank is slow to respond to academic recommendations to mitigate glyphosate‐resistant weeds, but represents a biological legacy that growers need to keep in mind even when management practices reduce emerged field weed population densities. © 2015 Society of Chemical Industry}, number={4}, journal={PEST MANAGEMENT SCIENCE}, author={Gibson, David J. and Young, Bryan G. and Owen, Micheal D. K. and Gage, Karla L. and Matthews, Joseph L. and Jordan, David L. and Shaw, David R. and Weller, Stephen C. and Wilson, Robert G.}, year={2016}, month={Apr}, pages={692–700} } @article{cahoon_york_jordan_seagroves_2015, title={Cotton response and Palmer amaranth control with mixtures of glufosinate and residual herbicides}, volume={19}, number={3}, journal={Journal of Cotton Science}, author={Cahoon, C. W. and York, A. C. and Jordan, D. L. and Seagroves, R. W.}, year={2015}, pages={622–630} } @article{cahoon_york_jordan_seagroves_everman_jennings_2015, title={Cotton response and Palmer amaranth control with pyroxasulfone applied preemergence and postemergence}, volume={19}, number={1}, journal={Journal of Cotton Science}, author={Cahoon, C. W. and York, A. C. and Jordan, D. L. and Seagroves, R. W. and Everman, W. J. and Jennings, K. M.}, year={2015}, pages={212–223} } @misc{foote_edmisten_wells_jordan_2015, title={Defoliant effects on cover crop germination, cover crop growth, and subsequent cotton (Gossypium hirsutum) development}, volume={19}, number={2}, journal={Journal of Cotton Science}, author={Foote, W. and Edmisten, K. and Wells, R. and Jordan, D.}, year={2015}, pages={258–267} } @article{braswell_york_jordan_seagroves_2015, title={Effect of diuron and fluometuron on grain sorghum and soybean as replacement crops following a cotton stand failure}, volume={19}, number={3}, journal={Journal of Cotton Science}, author={Braswell, L. R. and York, A. C. and Jordan, D. L. and Seagroves, R. W.}, year={2015}, pages={613–621} } @article{cahoon_york_jordan_seagroves_everman_jennings_2015, title={Fluridone carryover to rotational crops following application to cotton}, volume={19}, number={3}, journal={Journal of Cotton Science}, author={Cahoon, C. W. and York, A. C. and Jordan, D. L. and Seagroves, R. W. and Everman, W. J. and Jennings, K. M.}, year={2015}, pages={631–640} } @article{cardoza_drake_jordan_schroeder-moreno_arellano_brandenburg_2015, title={Impact of Location, Cropping History, Tillage, and Chlorpyrifos on Soil Arthropods in Peanut}, volume={44}, ISSN={["1938-2936"]}, DOI={10.1093/ee/nvv074}, abstractNote={ABSTRACT Demand for agricultural production systems that are both economically viable and environmentally conscious continues to increase. In recent years, reduced tillage systems, and grass and pasture rotations have been investigated to help maintain or improve soil quality, increase crop yield, and decrease labor requirements for production. However, documentation of the effects of reduced tillage, fescue rotation systems as well as other management practices, including pesticides, on pest damage and soil arthropod activity in peanut production for the Mid-Atlantic US region is still limited. Therefore, this project was implemented to assess impacts of fescue-based rotation systems on pests and other soil organisms when compared with cash crop rotation systems over four locations in eastern North Carolina. In addition, the effects of tillage (strip vs. conventional) and soil chlorpyrifos application on pod damage and soil-dwelling organisms were also evaluated. Soil arthropod populations were assessed by deploying pitfall traps containing 50% ethanol in each of the sampled plots. Results from the present study provide evidence that location significantly impacts pest damage and soil arthropod diversity in peanut fields. Cropping history also influenced arthropod diversity, with higher diversity in fescue compared with cash crop fields. Corn rootworm damage to pods was higher at one of our locations (Rocky Mount) compared with all others. Cropping history (fescue vs. cash crop) did not have an effect on rootworm damage, but increased numbers of hymenopterans, acarina, heteropterans, and collembolans in fescue compared with cash crop fields. Interestingly, there was an overall tendency for higher number of soil arthropods in traps placed in chlorpyrifos-treated plots compared with nontreated controls.}, number={4}, journal={ENVIRONMENTAL ENTOMOLOGY}, author={Cardoza, Yasmin J. and Drake, Wendy L. and Jordan, David L. and Schroeder-Moreno, Michelle S. and Arellano, Consuelo and Brandenburg, Rick L.}, year={2015}, month={Aug}, pages={951–959} } @article{worthington_reberg-horton_brown-guedira_jordan_weisz_murphy_2015, title={Morphological Traits Associated with Weed-Suppressive Ability of Winter Wheat against Italian Ryegrass}, volume={55}, ISSN={["1435-0653"]}, DOI={10.2135/cropsci2014.02.0149}, abstractNote={ABSTRACTWeed‐suppressive wheat (Triticum aestivum L.) cultivars have been suggested as a complement to chemical and cultural methods of weed control. The objectives of this study were to assess the range of weed‐suppressive ability against Italian ryegrass [Lolium perenne L. ssp. multiflorum (Lam.) Husnot] existing in winter wheat lines adapted to North Carolina and to identify wheat morphological traits that could facilitate indirect selection for weed suppression in the southeastern United States. Fifty‐three commercially available cultivars and advanced experimental lines were overseeded with a uniform, high rate of Italian ryegrass, evaluated for various morphological traits throughout the growing season, and investigated for weed‐suppressive ability at a total of four field sites. Genotypic differences in Italian ryegrass seed head density (P ≤ 0.05) were detected among the wheat lines. Reduced Italian ryegrass seed head density was correlated (P ≤ 0.05) with high vigor during tillering and heading (Zadoks growth stage [GS] 25, 29, 55), erect growth habit (GS 29), low normalized difference vegetation index (NDVI) (GS 29), high leaf area index (LAI) at stem extension (GS 31), early heading date, and tall height throughout the growing season (GS 29, 31, 55, 70 to 80) in three of four sites. Multiple regression models show that 71% of variation in weed‐suppressive ability was accounted for by final height (GS 70 to 80) and either height or plant vigor at late tillering (GS 29). Thus, breeders could improve weed‐suppressive ability using weighted index selection for genotypes that are tall or vigorous during tillering with tall final height.}, number={1}, journal={CROP SCIENCE}, publisher={Crop Science Society of America}, author={Worthington, Margaret and Reberg-Horton, S. Chris and Brown-Guedira, Gina and Jordan, David and Weisz, Randy and Murphy, J. Paul}, year={2015}, pages={50–56} } @article{cahoon_york_jordan_everman_seagroves_culpepper_eure_2015, title={Palmer Amaranth (Amaranthus palmeri) Management in Dicamba-Resistant Cotton}, volume={29}, ISSN={["1550-2740"]}, DOI={10.1614/wt-d-15-00041.1}, abstractNote={Cotton growers rely heavily upon glufosinate and various residual herbicides applied preplant, PRE, and POST to control Palmer amaranth resistant to glyphosate and acetolactate synthase-inhibiting herbicides. Recently deregulated in the United States, cotton resistant to dicamba, glufosinate, and glyphosate (B2XF cotton) offers a new platform for controlling herbicide-resistant Palmer amaranth. A field experiment was conducted in North Carolina and Georgia to determine B2XF cotton tolerance to dicamba, glufosinate, and glyphosate and to compare Palmer amaranth control by dicamba to a currently used, nondicamba program in both glufosinate- and glyphosate-based systems. Treatments consisted of glyphosate or glufosinate applied early POST (EPOST) and mid-POST (MPOST) in a factorial arrangement of treatments with seven dicamba options (no dicamba, PRE, EPOST, MPOST, PRE followed by [fb] EPOST, PRE fb MPOST, and EPOST fb MPOST) and a nondicamba standard. The nondicamba standard consisted of fomesafen PRE, pyrithiobac EPOST, and acetochlor MPOST. Dicamba caused no injury when applied PRE and only minor, transient injury when applied POST. At time of EPOST application, Palmer amaranth control by dicamba or fomesafen applied PRE, in combination with acetochlor, was similar and 13 to 17% greater than acetochlor alone. Dicamba was generally more effective on Palmer amaranth applied POST rather than PRE, and two applications were usually more effective than one. In glyphosate-based systems, greater Palmer amaranth control and cotton yield were obtained with dicamba applied EPOST, MPOST, or EPOST fb MPOST compared with the standard herbicides in North Carolina. In contrast, dicamba was no more effective than the standard herbicides in the glufosinate-based systems. In Georgia, dicamba was as effective as the standard herbicides in a glyphosate-based system only when dicamba was applied EPOST fb MPOST. In glufosinate-based systems in Georgia, dicamba was as effective as standard herbicides only when dicamba was applied twice.}, number={4}, journal={WEED TECHNOLOGY}, author={Cahoon, Charles W. and York, Alan C. and Jordan, David L. and Everman, Wesley J. and Seagroves, Richard W. and Culpepper, A. Stanley and Eure, Peter M.}, year={2015}, pages={758–770} } @article{worthington_reberg-horton_brown-guedira_jordan_weisz_murphy_2015, title={Relative Contributions of Allelopathy and Competitive Traits to the Weed Suppressive Ability of Winter Wheat Lines Against Italian Ryegrass}, volume={55}, ISSN={["1435-0653"]}, DOI={10.2135/cropsci2014.02.0150}, abstractNote={ABSTRACTAllelopathy and competitive ability have been identified as independent factors contributing to the weed suppressive ability of crop cultivars; however, it is not clear whether these factors have equal influence on weed suppression outcomes of winter wheat (Triticum aestivum L.) lines in the field. Fifty‐eight winter wheat lines adapted to the southeastern United States were screened for allelopathic activity against Italian ryegrass (Lolium perenne L. ssp. multiflorum [Lam.] Husnot) in an agar‐based seedling bioassay. Eight strongly and weakly allelopathic lines were identified and evaluated for weed suppressive ability and grain yield tolerance in a replicated field experiment conducted in North Carolina. Significant genotypic differences in weed suppressive ability were found in three of four study environments, while genotypic differences in yield tolerance were identified in all environments. Although the allelopathic activity of genotypes varied in the seedling bioassay, no correlations between allelopathy and weed suppressive ability or grain yield tolerance were observed. Weed suppressive ability was correlated with competitive traits, including vigor and erect growth habit during tillering (Zadoks GS 29), high leaf area index (LAI) at stem extension (GS 31), plant height at tillering and stem extension (GS 29, 31), grain yield in weedy conditions, and grain yield tolerance. Therefore, breeders in the southeastern United States should focus their efforts on improving competitive traits within adapted germplasm rather than selecting for cultivars with high allelopathic activity to achieve maximum gains in weed suppressive ability against Italian ryegrass.}, number={1}, journal={CROP SCIENCE}, publisher={Crop Science Society of America}, author={Worthington, Margaret and Reberg-Horton, S. Chris and Brown-Guedira, Gina and Jordan, David and Weisz, Randy and Murphy, J. Paul}, year={2015}, pages={57–64} } @article{chaudhari_jennings_monks_jordan_gunter_louws_2015, title={Response of Grafted Tomato (Solanum lycopersicum) to Herbicides}, volume={29}, ISSN={["1550-2740"]}, DOI={10.1614/wt-d-15-00037.1}, abstractNote={Tomato grafting has gained increased attention in the United States as an alternative to methyl bromide to control soilborne pests and diseases. Although several herbicides are registered in tomato production, a lack of information exists on the effect of herbicides on grafted tomato. Greenhouse and field experiments were conducted to determine herbicide tolerance of grafted tomato. In greenhouse experiments, halosulfuron (27, 54, and 108 g ai ha−1), metribuzin (280, 560, and 1,120 g ai ha−1), andS-metolachlor (1,070, 2,140, and 3,200 g ai ha−1) were applied posttransplant to nongrafted ‘Amelia' and Amelia scion grafted onto ‘Maxifort' or ‘RST-04-106-T' tomato rootstocks. Although herbicide injury was observed, no differences were observed in grafted and nongrafted tomato response including visible injury assessments, plant height, and fresh weight. Tomato injury at 3 wk after herbicide application increased from 3 to 12, 1 to 87, and 0 to 37% as rate of halosulfuron, metribuzin, andS-metolachlor increased, respectively. In field experiments under plasticulture, herbicides applied pretransplant included fomesafen (280 and 420 g ai ha−1), halosulfuron (39 and 54 g ha−1), metribuzin (280 and 560 g ha−1), napropamide (1,120 and 2,240 g ha−1),S-metolachlor (800 and 1,070 g ha−1), and trifluralin (560 and 840 g ai ha−1). Amelia was used as the scion and the nongrafted control. ‘Anchor-T', ‘Beaufort', or Maxifort tomato were used as rootstocks for grafted plants. Fomesafen, halosulfuron, napropamide, and trifluralin initially caused greater injury to grafted tomato than to nongrafted tomato regardless of rootstock (Anchor-T, Beaufort, or Maxifort). However, by 4 wk after treatment, all grafted and nongrafted plants had recovered from herbicide injury. A transplant type-by-herbicide interaction was not observed for yield, but grafted A-Maxifort tomato produced greater total and marketable yield than nongrafted Amelia tomato. Grafted tomato exhibited similar tolerance as nongrafted tomato for all herbicides applied post- and pretransplant.}, number={4}, journal={WEED TECHNOLOGY}, publisher={Cambridge University Press (CUP)}, author={Chaudhari, Sushila and Jennings, Katherine M. and Monks, David W. and Jordan, David L. and Gunter, Christopher C. and Louws, Frank J.}, year={2015}, pages={800–809} } @article{schwartz_gibson_gage_matthews_jordan_owen_shaw_weller_wilson_young_2015, title={Seedbank and Field Emergence of Weeds in Glyphosate-Resistant Cropping Systems in the United States}, volume={63}, ISSN={["1550-2759"]}, DOI={10.1614/ws-d-14-00089.1}, abstractNote={A segment of the debate surrounding the commercialization and use of glyphosate-resistant (GR) crops focuses on the theory that the implementation of these traits is an extension of the intensification of agriculture that will further erode the biodiversity of agricultural landscapes. A large field-scale study was initiated in 2006 in the United States on 156 different field sites with a minimum 3-yr history of GR-corn, -cotton or -soybean in the cropping system. The impact of cropping system, crop rotation, frequency of using the GR crop trait, and several categorical variables on seedbank weed population density and diversity was analyzed. The parameters of total weed population density of all species in the seedbank, species richness, Shannon's H′ and evenness were not affected by any management treatment. The similarity between the seedbank and aboveground weed community was more strongly related to location than management; previous year's crops and cropping systems were also important while GR trait rotation was not. The composition of the weed flora was more strongly related to location (geography) than any other parameter. The diversity of weed flora in agricultural sites with a history of GR crop production can be influenced by several factors relating to the specific method in which the GR trait is integrated (cropping system, crop rotation, GR trait rotation), the specific weed species, and the geographical location. Continuous GR crop, compared to fields with other cropping systems, only had greater species diversity (species richness) of some life forms, i.e., biennials, winter annuals, and prostrate weeds. Overall diversity was related to geography and not cropping system. These results justify further research to clarify the complexities of crops grown with herbicide-resistance traits to provide a more complete characterization of their culture and local adaptation to the weed seedbank.}, number={2}, journal={WEED SCIENCE}, author={Schwartz, Lauren M. and Gibson, David J. and Gage, Karla L. and Matthews, Joseph L. and Jordan, David L. and Owen, Micheal D. K. and Shaw, David R. and Weller, Stephen C. and Wilson, Robert G. and Young, Bryan G.}, year={2015}, pages={425–439} } @misc{cahoon_york_jordan_seagroves_everman_jennings_2015, title={Sequential and co-application of glyphosate and glufosinate in cotton}, volume={19}, number={2}, journal={Journal of Cotton Science}, author={Cahoon, C. W. and York, A. C. and Jordan, D. L. and Seagroves, R. W. and Everman, W. J. and Jennings, K. M.}, year={2015}, pages={337–350} } @article{cahoon_york_jordan_everman_seagroves_braswell_jennings_2015, title={Weed Control in Cotton by Combinations of Microencapsulated Acetochlor and Various Residual Herbicides Applied Preemergence}, volume={29}, ISSN={["1550-2740"]}, DOI={10.1614/wt-d-15-00061.1}, abstractNote={Residual herbicides are routinely recommended to aid in control of glyphosate-resistant (GR) Palmer amaranth in cotton. Acetochlor, a chloroacetamide herbicide, applied PRE, controls Palmer amaranth. A microencapsulated (ME) formulation of acetochlor is now registered for PRE application in cotton. Field research was conducted in North Carolina to evaluate cotton tolerance and Palmer amaranth control by acetochlor ME alone and in various combinations. Treatments, applied PRE, consisted of acetochlor ME, pendimethalin, or no herbicide arranged factorially with diuron, fluometuron, fomesafen, diuron plus fomesafen, and no herbicide. The PRE herbicides were followed by glufosinate applied twice POST and diuron plus MSMA directed at layby. Acetochlor ME was less injurious to cotton than pendimethalin. Acetochlor ME alone or in combination with other herbicides reduced early season cotton growth 5 to 8%, whereas pendimethalin alone or in combinations injured cotton 11 to 13%. Early season injury was transitory, and by 65 to 84 d after PRE treatment, injury was no longer noticeable. Before the first POST application of glufosinate, acetochlor ME and pendimethalin controlled Palmer amaranth 84 and 64%, respectively. Control by acetochlor ME was similar to control by diuron plus fomesafen and greater than control by diuron, fluometuron, or fomesafen alone. Greater than 90% control was obtained with acetochlor ME mixed with diuron or fomesafen. Palmer amaranth control was similar with acetochlor ME plus a full or reduced rate of fomesafen. Acetochlor ME controlled large crabgrass and goosegrass at 91 and 100% compared with control at 83 and 91%, respectively, by pendimethalin. Following glufosinate, applied twice POST, and diuron plus MSMA, at layby, 96 to 99% control was obtained late in the season by all treatments, and no differences among herbicide treatments were noted for cotton yield. This research demonstrated that acetochlor ME can be safely and effectively used in cotton weed management programs.}, number={4}, journal={WEED TECHNOLOGY}, author={Cahoon, Charles W. and York, Alan C. and Jordan, David L. and Everman, Wesley J. and Seagroves, Richard W. and Braswell, Lewis R. and Jennings, Katherine M.}, year={2015}, pages={740–750} } @article{meyers_jennings_monks_ballington_jordan_2016, title={Weed Control in Southern Highbush Blueberry with S-metolachlor, Flumioxazin, and Hexazinone}, volume={16}, ISSN={["1553-8362"]}, DOI={10.1080/15538362.2015.1072490}, abstractNote={Abstract Field studies were conducted in 2010, 2011, and 2012 at a commercial blueberry farm near Burgaw, NC to determine weed control and crop tolerance to S-metolachlor and flumioxazin alone or mixed with hexazinone. Herbicides were applied pre-budbreak and postharvest. Pre-budbreak applications consisted of hexazinone at 1.1 or 2.2 kg ai ha−1, S-metolachlor at 1.4 or 2.8 kg ai ha–1, and flumioxazin at 215 g ai ha–1 alone and tank mixes of hexazinone or flumioxazin plus S-metolachlor. Additional treatments consisted of flumioxazin (215 g ha–1), flumioxazin plus S-metolachlor (1.4 and 2.8 kg ha–1), or hexazinone (1.1 kg ha–1) plus S-metolachlor (1.4 and 2.8 kg ha–1) applied pre-budbreak and followed by (fb) a postharvest application of flumioxazin (215 g ha–1). Herbicide programs containing flumioxazin resulted in greater Maryland meadowbeauty control (73%) 5 to 6 weeks after treatment (WAT) than herbicide programs containing hexazinone at 1.1 or 2.2 kg ha–1 (37% and 39%, respectively). Needleleaf rosette grass control remained ≥94% for all herbicide programs through 2 WAT. Hexazinone at 1.1 kg ha–1 provided greater needleleaf rosette grass control (87%) than flumioxazin (71%) 5 to 6 WAT. Meadowbeauty and needleleaf rosette grass control by all herbicide programs was poor (≤39% and ≤57%, respectively) 16 to 18 WAT. Two weeks after post-harvest applications, herbicide programs receiving a post-harvest flumioxazin application had greater meadowbeauty and needleleaf rosette grass control (78% and 84%, respectively) than those programs without a post-harvest flumioxazin application (43% and 71%, respectively).}, number={2}, journal={INTERNATIONAL JOURNAL OF FRUIT SCIENCE}, author={Meyers, Stephen L. and Jennings, Katherine M. and Monks, David W. and Ballington, James R. and Jordan, David L.}, year={2016}, pages={150–158} } @article{cahoon_york_jordan_everman_seagroves_2014, title={An Alternative to Multiple Protoporphyrinogen Oxidase Inhibitor Applications in No-Till Cotton}, volume={28}, ISSN={["1550-2740"]}, DOI={10.1614/wt-d-13-00078.1}, abstractNote={Glyphosate-resistant (GR) Palmer amaranth is a widespread problem in southeastern cotton production areas. Herbicide programs to control this weed in no-till cotton commonly include flumioxazin applied with preplant burndown herbicides approximately 3 wk before planting followed by fomesafen applied PRE and then glufosinate or glyphosate applied POST. Flumioxazin and fomesafen are both protoporphyrinogen oxidase (PPO) inhibitors. Multiple yearly applications of PPO inhibitors in cotton, along with widespread use of PPO inhibitors in rotational crops, raise concerns over possible selection for PPO resistance in Palmer amaranth. An experiment was conducted to determine the potential to substitute diuron for one of the PPO inhibitors in no-till cotton. Palmer amaranth control by diuron and fomesafen applied PRE varied by location, but fomesafen was generally more effective. Control by both herbicides was inadequate when timely rainfall was not received for activation. Palmer amaranth control was more consistent when programs included a preplant residual herbicide. Applied preplant, flumioxazin was more effective than diuron. Programs with diuron preplant followed by fomesafen PRE were as effective as flumioxazin preplant followed by fomesafen only if fomesafen was activated in a timely manner. Programs with flumioxazin preplant followed by diuron PRE were as effective as flumioxazin preplant followed by fomesafen PRE at all locations, regardless of timely activation of the PRE herbicide. As opposed to flumioxazin preplant followed by fomesafen PRE, which exposes Palmer amaranth to two PPO-inhibiting herbicides, one could reduce selection pressure by using flumioxazin preplant followed by diuron PRE without sacrificing Palmer amaranth control or cotton yield.}, number={1}, journal={WEED TECHNOLOGY}, author={Cahoon, Charles W. and York, Alan C. and Jordan, David L. and Everman, Wesley J. and Seagroves, Richard W.}, year={2014}, pages={58–71} } @article{edwards_jordan_owen_dixon_young_wilson_weller_shaw_2014, title={Benchmark study on glyphosate-resistant crop systems in the United States. Economics of herbicide resistance management practices in a 5 year field-scale study}, volume={70}, ISSN={["1526-4998"]}, DOI={10.1002/ps.3759}, abstractNote={AbstractBACKGROUNDSince the introduction of glyphosate‐resistant (GR) crops, growers have often relied on glyphosate‐only weed control programs. As a result, multiple weeds have evolved resistance to glyphosate. A 5 year study including 156 growers from Illinois, Iowa, Indiana, Nebraska, North Carolina and Mississippi in the United States was conducted to compare crop yields and net returns between grower standard weed management programs (SPs) and programs containing best management practices (BMPs) recommended by university weed scientists. The BMPs were designed to prevent or mitigate/manage evolved herbicide resistance.RESULTSWeed management costs were greater for the BMP approach in most situations, but crop yields often increased sufficiently for net returns similar to those of the less expensive SPs. This response was similar across all years, geographical regions, states, crops and tillage systems.CONCLUSIONSHerbicide use strategies that include a diversity of herbicide mechanisms of action will increase the long‐term sustainability of glyphosate‐based weed management strategies. Growers can adopt herbicide resistance BMPs with confidence that net returns will not be negatively affected in the short term and contribute to resistance management in the long term. © 2014 Society of Chemical Industry}, number={12}, journal={PEST MANAGEMENT SCIENCE}, author={Edwards, C. Blake and Jordan, David L. and Owen, Michael D. K. and Dixon, Philip M. and Young, Bryan G. and Wilson, Robert G. and Weller, Steven C. and Shaw, David R.}, year={2014}, month={Dec}, pages={1924–1929} } @article{jordan_johnson_grabow_corbett_2014, title={Corn, cotton, and peanut response to tillage and subsurface drip irrigation in north carolina}, volume={106}, DOI={10.2134/agronj13.0486}, abstractNote={Determining response of agronomic crops to subsurface drip irrigation (SDI) in conventional and reduced tillage systems is important in defining utility of SDI. Therefore, the objectives of this research were to define interactions of SDI and tillage with respect to yield and economic return of corn (Zea mays L.), cotton (Gossypium hirsutum L.), and peanut (Arachis hypogaea L.) planted in rotation. Research was conducted in two 4‐yr periods (2007–2010 and 2008–2011) in North Carolina using continuous strip tillage vs. continuous conventional tillage without irrigation or with SDI using a crop sequence of 1 yr of cotton, 2 yr of corn, followed by 1 yr of peanut. Corn, cotton, and peanut yields increased with SDI compared with no irrigation regardless of tillage system. Cotton and peanut yields were not affected by tillage system or the interaction of tillage and irrigation; corn yield was affected by this interaction. In the second year of corn, yield and economic return were higher in conventional tillage with SDI than strip tillage with SDI. Economic return for the sum of crops in the rotation was affected by the interaction of irrigation and tillage. Economic return was higher in both periods during each year corn was grown under SDI compared with non‐irrigated corn while higher economic returns for cotton and peanut under SDI were noted in one of two periods. When pooled over periods, crops, and tillage, economic return for SDI was US$1,552 ha−1 higher than non‐irrigated production over 4 yr.}, number={3}, journal={Agronomy Journal}, author={Jordan, D. L. and Johnson, P. D. and Grabow, G. L. and Corbett, T.}, year={2014}, pages={962–967} } @article{drake_jordan_johnson_shew_brandenburg_corbett_2014, title={Peanut Response to Planting Date, Tillage, and Cultivar in North Carolina}, volume={106}, ISSN={["1435-0645"]}, DOI={10.2134/agronj2013.0340}, abstractNote={Production of peanut (Arachis hypogaea L.) in reduced tillage is an effective alternative to conventional tillage in the southeastern United States under some conditions. Research was conducted to determine interactions of planting date, tillage system, and cultivar with respect to disease reaction and pod yield of peanut. The cultivars Bailey, CHAMPS, Gregory, Perry, and Phillips were planted in early or late May in reduced or conventional tillage systems from 2008 through 2011 at one location in North Carolina. The interaction of year, tillage system, and cultivar was significant for plant condition rating (PCR), a visible estimate of disease, within 3 d before digging from late September through mid‐October. Pod yield was correlated with PCR in mid‐September (P = 0.0001, R2 = –0.22) and PCR just before digging (P ≤ 0.0001, R2 = –0.31). Disease was less prevalent for the cultivar Bailey and most prevalent for the cultivar Phillips, with disease for the other cultivars intermediate between Bailey and Phillips. Pod yield was influenced independently by cultivar, planting date, and tillage system although each of these factors was affected by year of the experiment. Pod yield was similar in strip tillage and conventional tillage in 3 of 4 yr with yield in strip tillage exceeding conventional tillage in 1 yr. Peanut planted in early May yielded more than peanut planted in late May in 2 of 4 yr. Results indicate that while some differences in disease reaction will occur when comparing cultivars, planting dates, and tillage systems, pod yield will be affected independently by these cultural practices.}, number={2}, journal={AGRONOMY JOURNAL}, author={Drake, W. L. and Jordan, D. L. and Johnson, P. D. and Shew, B. B. and Brandenburg, R. L. and Corbett, T.}, year={2014}, pages={486–490} } @article{riar_spears_burns_jordan_zhang_rufty_2014, title={Persistence of Benghal dayflower (Commelina benghalensis) in sustainable agronomic systems: Potential impacts of hay bale storage, animal digestion, and cultivation}, volume={38}, DOI={10.1080/21683565.2013.839486}, abstractNote={Experiments were conducted to evaluate factors affecting persistence of the invasive, federal noxious weed Benghal dayflower in sustainable agronomic systems. Seeds were exposed to a range of temperatures simulating those found in hay bales in the field and periodically tested for viability over 21 days. Seeds were nonviable after one day at 65 °C and after 14 days at 50 or 45 °C. A second series of experiments examined the effects of simulated rumen digestion on germination and viability of Benghal dayflower seeds and the response was compared to that with seeds of five other common weed species. Time courses revealed that seeds from the other weeds were acutely damaged by digestion and viability depressed after 48 and 96 h, but germination of Benghal dayflower seeds was increased at 48 h, and only a slight decrease occurred after 96 h. In the third experimental series, stem fragments of Benghal dayflower were buried in soil at 2 and 6 cm depths and exposed to aerial temperatures of 20, 25, 30, and 35 °C for 30 days. Root development occurred at both depths, but leaf development was restricted at 6 cm and subterranean spathe development was not found at 2 cm. Temperatures higher than 25 °C favor regeneration at both depths. The results, collectively, show the difficulty encountered when trying to control or eradicate Benghal dayflower in sustainable farming systems. Farms must avoid using fresh hay as animal feed when Benghal dayflower is present in hay fields, as little restraint on seed viability will be exerted during digestion and generation of manure. Cultivation is unlikely to be an effective control strategy during summer months when Benghal dayflower is growing most aggressively, because soil temperatures are optimal for vegetative regeneration.}, number={3}, journal={Agroecology and Sustainable Food Systems}, author={Riar, M. K. and Spears, J. F. and Burns, J. C. and Jordan, D. L. and Zhang, C. X. and Rufty, T. W.}, year={2014}, pages={283–298} } @article{roberson_jordan_2014, title={RTK GPS and automatic steering for peanut digging}, volume={30}, DOI={10.13031/aea.30.10432}, abstractNote={Abstract. Peanut harvesting is a two-stage process. In the first stage, a digger-shaker-inverter implement is used to plow peanut from the ground. In the second stage, a combine is used to thresh peanut pods from the vines. Yield loss can be significant, especially during the digging stage where the implement may not be properly aligned over the rows of peanut. In this study, RTK-based automatic steering was compared to manual steering to determine the potential for reduced yield losses. In addition, peanut response to the plant growth regulator prohexadione calcium was compared to a non-treated peanut to determine if reduced yield losses were obtainable. Prohexadione calcium regulator did not improve yield significantly. However, use of RTK based automatic steering was significant, increasing harvested yield by 510 kg/ha or 11%.}, number={3}, journal={Applied Engineering in Agriculture}, author={Roberson, Gary and Jordan, D. L.}, year={2014}, pages={405–409} } @article{narh_boote_naab_abudulai_bertin_sankara_burow_tillman_brandenburg_jordan_2014, title={Yield Improvement and Genotype x Environment Analyses of Peanut Cultivars in Multilocation Trials in West Africa}, volume={54}, ISSN={["1435-0653"]}, DOI={10.2135/cropsci2013.10.0657}, abstractNote={ABSTRACTYield trials are used in plant breeding programs to evaluate the yield potential and stability of selected lines. The objectives of this study were to evaluate yield potential, genotype × environment interactions, and stability of peanut genotypes for the savannah region of West Africa. Twenty peanut (Arachis hypogaea L.) genotypes were tested at two sites in Ghana and two sites in Burkina Faso in 2010 and 2011. The experimental design was a randomized complete block design with three replicates. Genotype, location, and genotype × environment interactions were highly significant, indicating genetic variability among genotypes across changing environments. Stability analyses showed that genotypes ICGV‐IS 96814, ICGV (FDRS)‐20 × F‐MIX 39, Gusie Balin (92099), ICGV‐IS 92093, and ICGV‐IS 92101 had broad adaptability, with above‐average yield across sites and a regression coefficient close to 1.0. Genotype ICGV‐IS 96814 produced the highest pod yield (1760 kg ha−1) across all environments and had a regression coefficient close to unity (b = 1.06). Therefore, genotype ICGV‐IS 96814 is less responsive to varied environmental and soil conditions. However, the released cultivar Nkatesari was considered equivalent in some respects because it had pod yield equal to ICGV‐IS 96814 but with a higher regression coefficient. High‐yielding cultivars, mostly from ICRISAT‐derived crosses, yielded nearly 80% more than the three farmer check cultivars TS 32–1, Doumbala, and Chinese, which had pod yields from 890 to 980 kg ha−1. The higher‐yielding cultivars had longer life cycle, greater leaf spot resistance, and higher partitioning than the farmer check cultivars.}, number={6}, journal={CROP SCIENCE}, author={Narh, Stephen and Boote, Kenneth J. and Naab, Jesse B. and Abudulai, Mumuni and Bertin, Zagre M'Bi and Sankara, Philippe and Burow, Mark D. and Tillman, Barry L. and Brandenburg, Rick L. and Jordan, David L.}, year={2014}, pages={2413–2422} } @article{worthington_reberg-horton_jordan_murphy_2013, title={A Comparison of Methods for Evaluating the Suppressive Ability of Winter Wheat Cultivars against Italian Ryegrass (Lolium perenne)}, volume={61}, ISSN={["1550-2759"]}, DOI={10.1614/ws-d-12-00167.1}, abstractNote={Infestations of Italian ryegrass are problematic in both conventional and organic wheat production systems. The development of wheat cultivars with superior competitive ability against Italian ryegrass could play a role in maintaining acceptable yields and suppressing weed populations. Research was conducted in North Carolina to identify indirect methods of selection for Italian ryegrass suppressive ability (hereafter referred to as weed suppressive ability) of winter wheat cultivars that correlate well with Italian ryegrass-to-wheat biomass ratios. Two winter wheat cultivars (Dyna-Gro Baldwin and Dyna-Gro Dominion) and one experimental wheat line (NC05-19684) with differing morphological traits were overseeded with varying densities of Italian ryegrass. Wheat height measured throughout the growing season in weed-free plots was strongly associated with weed suppressive ability, but high wheat tillering capacity had no significant effect on weed suppressive ability in the lines tested in this study. Italian ryegrass seed head density during grain fill was strongly correlated (r= 0.94) with Italian ryegrass-to-wheat biomass ratio, the generally accepted measure of weed suppressive ability. Visual estimates of percent Italian ryegrass biomass relative to the plot with the highest level of Italian ryegrass infestation in each replicate were also strongly correlated with weed suppressive ability at all growth stages, especially during heading (r= 0.87) (Zadoks growth stage [GS] 55). Measurements from nonimaging spectrophotometers and overhead photographs taken from tillering (Zadoks 23 to 25) to early dough development (Zadoks 80) were unreliable estimates of end-of-season Italian ryegrass-to-wheat biomass ratios because they failed to account for wheat cultivar differences in biomass, color, and growth habit. Italian ryegrass seed head density and visual estimates of Italian ryegrass biomass during grain fill are appropriate indirect methods of selection for weed suppressive ability in breeding programs.}, number={3}, journal={WEED SCIENCE}, publisher={Cambridge University Press (CUP)}, author={Worthington, Margaret L. and Reberg-Horton, S. Chris and Jordan, David and Murphy, J. Paul}, year={2013}, pages={491–499} } @article{young_gibson_gage_matthews_jordan_owen_shaw_weller_wilson_2013, title={Agricultural Weeds in Glyphosate-Resistant Cropping Systems in the United States}, volume={61}, ISSN={["1550-2759"]}, DOI={10.1614/ws-d-12-00001.1}, abstractNote={A segment of the debate surrounding the commercialization of genetically engineered (GE) crops, such as glyphosate-resistant (GR) crops, focuses on the theory that implementation of these traits is an extension of the intensification of agriculture that will further erode the biodiversity of agricultural landscapes. A large field-scale study was conducted in 2006 in the United States on 156 different field sites with a minimum 3-yr history of GR corn, cotton, or soybean in the cropping system. The impact of cropping system, crop rotation, frequency of using the GR crop trait, and several categorical variables on emerged weed density and diversity was analyzed. Species richness, evenness, Shannon's H′, proportion of forbs, erect growth habit, and C3species diversity were all greater in agricultural sites that lacked crop rotation or were in a continuous GR crop system. Rotating between two GR crops (e.g., corn and soybean) or rotating to a non-GR crop resulted in less weed diversity than a continuous GR crop. The composition of the weed flora was more strongly related to location (geography) than any other parameter. The diversity of weed flora in agricultural sites with a history of GR crop production can be influenced by several factors relating to the specific method in which the GR trait is integrated (cropping system, crop rotation, GR trait rotation), the specific weed species, and the geographical location. The finding that fields with continuous GR crops demonstrated greater weed diversity is contrary to arguments opposing the use of GE crops. These results justify further research to clarify the complexities of crops grown with herbicide-resistance traits, or more broadly, GE crops, to provide a more complete characterization of their culture and local adaptation.}, number={1}, journal={WEED SCIENCE}, author={Young, Bryan G. and Gibson, David J. and Gage, Karla L. and Matthews, Joseph L. and Jordan, David L. and Owen, Micheal D. K. and Shaw, David R. and Weller, Stephen C. and Wilson, Robert G.}, year={2013}, pages={85–97} } @article{riar_wells_edmisten_jordan_bacheler_2013, title={Cotton Yield and Canopy Closure in North Carolina as Influenced by Row Width, Plant Population, and Leaf Morphology}, volume={53}, ISSN={["0011-183X"]}, DOI={10.2135/cropsci2012.08.0490}, abstractNote={ABSTRACTCotton (Gossypium hirsutum L.) yield is partly determined by crop geometry, which is a function of row width and plant population. Field experiments were conducted in North Carolina during 2007 and 2008 to test the hypothesis that row width will be the determining factor in attaining canopy closure and hence greater fiber yield in North Carolina. The influences of both plant population and leaf morphology on the row width effects were also examined. Okra‐leaf (FiberMax 800 BR) and normal‐leaf (FiberMax 960 BR) cultivars were planted at 38‐ and 97‐cm row widths at populations of 7, 12, and 18 plants m−2. Cotton grown at 38‐cm row width yielded more than cotton grown at 97‐cm rows in some but not all environments. The percentage of canopy closure and the percentage of photosynthetically active radiation interception showed a close relationship over row width, leaf morphology, plant population, and environment (r2 = 0.84, P < 0.001). Higher plant population increased light interception and canopy closure early in the season. However, with time, these differences were reduced and were absent by the last observations. Row width was an important cause of greater canopy closure but this did not consistently translate into yield differences and yields were more closely affected by cumulative rainfall. Economic analysis found no loss of profit in the lowest plant population in either row width indicating that seed costs could be reduced without decreasing yield.}, number={4}, journal={CROP SCIENCE}, author={Riar, Ranjit and Wells, Randy and Edmisten, Keith and Jordan, David and Bacheler, Jack}, year={2013}, pages={1704–1711} } @article{meyers_jennings_monks_jordan_ballington_2013, title={Effect of PRE and POST Herbicides on Carolina Redroot (Lachnanthes caroliniana) Growth}, volume={27}, ISSN={["0890-037X"]}, DOI={10.1614/wt-d-13-00029.1}, abstractNote={Greenhouse studies were conducted in Raleigh, NC to determine Carolina redroot control by selected PRE and POST herbicides labeled for blueberries. Paraquat, glufosinate, glyphosate, and flumioxazin provided some Carolina redroot shoot control 7 d after POST application (DAPOST) ranging from 48 to 74%. Control 25 DAPOST was greatest for hexazinone at 2.2 kg ai ha−1(90%) followed by glufosinate with 56% control and paraquat and terbacil each with 53% control. Control for most treatments declined between 25 and 63 DAPOST with the exception of glyphosate, which increased to 64%. Carolina redroot shoots per pot were reduced by terbacil, hexazinone at 2.2 kg ha−1, and glyphosate compared with the nontreated check 63 DAPOST. Control of Carolina redroot roots and rhizomes 63 DAPOST ranged from 7 to 68%, with the greatest control provided by terbacil (68%) and hexazinone at 2.2 kg ha−1(64%). Terbacil and hexazinone at 2.2 kg ha−1were the only treatments that reduced both shoot and root/rhizome dry weight compared with the nontreated check.}, number={4}, journal={WEED TECHNOLOGY}, author={Meyers, Stephen L. and Jennings, Katherine M. and Monks, David W. and Jordan, David L. and Ballington, James R.}, year={2013}, pages={747–751} } @article{abudulai_salifu_opare-atakora_haruna_baba_dzomeku_brandenburg_jordan_2013, title={Field Efficacy of Neem (Azadirachta indica A. Juss) for Managing Soil Arthropods and Cercospora Leaf Spots Damage for Increased Yield in Peanut}, volume={49}, ISSN={["1805-9341"]}, DOI={10.17221/48/2012-pps}, abstractNote={Field efficacy of neem (Azadirachta indica A. Juss) for managing soil arthropods and Cercospora leaf spots damage to peanut was studied in Ghana from 2008 to 2010. Treatments consisted of neem kernel water extract (NKWE) and neem kernel powder (NKP) applied separately as soil drench at the rates of 10.5 and 21.0 kg/ha at either planting or pegging. Untreated control and chlorpyrifos treatment at pegging were included as checks. Results showed generally that the neem products at the concentrations tested were efficacious and comparable to chlorpyrifos in lowering populations of soil arthropods and severity of leaf spot diseases, leaf defoliation, and scarified and bored pod damage, resulting in increased pod yield in 2008 and 2009}, number={2}, journal={PLANT PROTECTION SCIENCE}, author={Abudulai, Mumuni and Salifu, Abdulai B. and Opare-Atakora, Danial and Haruna, Mohammed and Baba, Inusah I. Y. and Dzomeku, Israel K. and Brandenburg, Rick L. and Jordan, David L.}, year={2013}, month={Jun}, pages={65–72} } @article{chandi_jordan_york_milla-lewis_burton_culpepper_whitaker_2013, title={Interference and control of glyphosate-resistant and –susceptible Palmer amaranth (Amaranthus palmeri) populations under greenhouse conditions}, volume={61}, ISSN={["1550-2759"]}, DOI={10.1614/ws-d-12-00063.1}, abstractNote={Interference for 40 d after emergence (DAE) of corn, cotton, peanut, and snap bean by four glyphosate-resistant (GR) and four glyphosate-susceptible (GS) Palmer amaranth populations from Georgia and North Carolina was compared in the greenhouse. Greater interference from Palmer amaranth, measured as crop height and fresh weight reduction, was noted in cotton and peanut compared with corn or snap bean. Crop height 15 to 40 DAE was reduced similarly by GR and GS populations. Crop fresh weight, however, was reduced 25 and 19% in the presence of GS and GR populations, respectively. Measured as percent reduction in fresh weight, GR and GS populations of Palmer amaranth were controlled similarly by glufosinate, lactofen, paraquat, and trifloxysulfuron applied POST. Atrazine and dicamba controlled GR populations more effectively than GS populations.}, number={2}, journal={Weed Science}, publisher={Weed Science Society}, author={Chandi, A. and Jordan, D.L. and York, A.C. and Milla-Lewis, S.R. and Burton, J.D. and Culpepper, A.S. and Whitaker, J.R.}, year={2013}, pages={259–266} } @article{meyers_jennings_monks_ballington_jordan_2013, title={POST Control of Carolina Redroot (Lachnanthes caroliniana)}, volume={27}, ISSN={["0890-037X"]}, DOI={10.1614/wt-d-12-00164.1}, abstractNote={Greenhouse studies were conducted in 2012 in Raleigh, NC to determine Carolina redroot control by ten POST herbicides. Paraquat and glufosinate provided the greatest control 14 (73 and 64%, respectively) and 25 d (82 and 68%, respectively) after treatment (DAT), but control declined between 25 and 63 DAT (72 and 59%, respectively). Glyphosate provided minimal control 14 DAT (18%), and control increased from 14 to 25 DAT (46%) and 25 to 63 DAT (69%). Control of Carolina redroot roots and rhizomes (roots/rhizomes) was greatest in plants treated with paraquat (91%), glyphosate (88%), glufosinate (73%), hexazinone (62%), diuron (60%). Nontreated Carolina redroot shoot and root/rhizome dry weight were 8.3 and 7.6 g, respectively. Paraquat, glufosinate, glyphosate, and diuron reduced both shoot and root/rhizome dry weight (3.1 and 0.7 g, 5.1 and 2.7 g, 5.4 and 1.0, 5.7 and 1.6 g, respectively). Hexazinone reduced root/rhizome dry weight (2.7 g). Fomesafen reduced shoot dry weight (6.1 g), but did not reduce root/rhizome dry weight. Paraquat, glufosinate, glyphosate, hexazinone, diuron, and clopyralid treatments resulted in reduced incidence of Carolina redroot flowering and anthesis.}, number={3}, journal={WEED TECHNOLOGY}, author={Meyers, Stephen L. and Jennings, Katherine M. and Monks, David W. and Ballington, James R. and Jordan, David L.}, year={2013}, pages={534–537} } @article{vann_fisher_jordan_smith_hardy_stewart_2013, title={Potassium Rate and Application Effect on Flue-Cured Tobacco}, volume={105}, ISSN={["0002-1962"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84875203584&partnerID=MN8TOARS}, DOI={10.2134/agronj2012.0259}, abstractNote={Research was conducted at two locations in 2009 and 2010 to evaluate the effect of various K rates and application methods on the yield and quality of flue‐cured tobacco (Nicotiana tabacum L.). Treatments included five rates of K from sulfate of potash magnesia (0–0–22): 0, 84, 140, 196, and 252 kg K2O ha−1 that were applied: broadcast 1 mo before transplanting, broadcast 1 wk before transplanting, banded at transplanting, and a split application with one‐half rate banded at transplanting followed by one‐half rate banded at layby. Tissue samples were collected throughout the season at three separate growth stages: layby, topping, and after curing. Tissue samples were analyzed for total alkaloid and reducing sugars, N, P, K, and Mg content. Soil samples were collected the same day as K fertilizer application from plots not receiving supplemental K. Data were subjected to ANOVA using the PROC GLM procedure in SAS. Treatment means were separated using Fisher’s Protected LSD test at p ≤ 0.05. Application method and timing had no effect on any measured parameters; furthermore, crop yield and quality was not affected by K rates >0 kg K2O ha−1 at three of four locations. It is likely that early broadcast applications of K2O with current rate recommendations would only be of concern with combinations of conditions that included coarse soil textures, low K indices, and/or excessive leaching rainfall.}, number={2}, journal={AGRONOMY JOURNAL}, author={Vann, Matthew C. and Fisher, Loren R. and Jordan, David L. and Smith, W. David and Hardy, David H. and Stewart, Alexander M.}, year={2013}, pages={304–310} } @article{gibson_gage_matthews_young_owen_wilson_weller_shaw_jordan_2013, title={The effect of weed management systems and location on arable weed species communities in glyphosate-resistant cropping systems}, volume={16}, ISSN={["1654-109X"]}, DOI={10.1111/avsc.12039}, abstractNote={AbstractQuestionHow do different weed management systems based on glyphosate‐resistant (GR) crops affect weed community structure and composition?LocationA total of 156 agricultural fields across six US states.MethodsFields were selected and categorized into three weed management systems based on a 3‐yr history: (1) a single continuous GR crop; (2) a rotation of two GR crops; and (3) a GR crop rotated with a non‐GR crop. Weed species population density was surveyed in 20 0.5‐m2 plots per field four times each season from 2006 to 2010. Weed population density, species richness and diversity were analysed using repeated measures mixed models to test the effect of year, geographic location (based on plant hardiness zone) and weed management system (as described above). Weed community composition was analysed using NMDS ordination. The importance of geographic location, planted crop and weed management system were analysed using analysis of similarity and permutational ANOVA based on the Bray–Curtis similarity among sites calculated from the maximum weed species population density per site per year.ResultsA total of 329 weed species were identified across the six states and all time periods. Weed communities were most strongly correlated with geographic location and secondarily to the crop planted. Weed management system affected similarity among weed communities through an interaction with site location but not every year. The weed management systems of crop rotation and GR trait rotation generally reduced weed population density and species diversity, but the effect of crop rotation varied by geographic location.ConclusionsThe overall effects of weed management systems in fields including the GR trait on arable weed communities reinforce the need for locally adapted weed management programmes to steward the GR crop trait to manage for high weed diversity while reducing crop–weed competition and maximizing yield.}, number={4}, journal={APPLIED VEGETATION SCIENCE}, author={Gibson, David J. and Gage, Karla L. and Matthews, Joseph L. and Young, Bryan G. and Owen, Micheal D. K. and Wilson, Robert G. and Weller, Stephen C. and Shaw, David R. and Jordan, David L.}, year={2013}, month={Oct} } @article{mochiah_owusu-akyaw_bolfrey-arku_osei_lamptey_adama_amoabeng_brandenburg_jordan_2013, title={The use of sugar baits for the integrated management of soil arthropod pests in peanut (Arachis hypogaea L.) in Ghana, West Africa}, volume={21}, DOI={10.4001/003.021.0210}, abstractNote={Soil arthropods cause kernel and pod damage and can lower yields of peanut (Arachis hypogaea L.) in Ghana, West Africa. On-station and on-farm experiments were conducted during 2007 and 2008 at Kwadaso and Hiawoannwu, respectively, using an improved peanut cultivar/line RRR-ICGU 88709 in a soil arthropod pests management trial. The trial included four treatments, i.e. chlorpyrifos (Dursban™) insecticide as a standard, three levels of granulated sugar as baits, and an untreated control. Soil arthropod pests observed in peanut plots during both years from the two locations were white grubs, millipedes, symphilids, termites, earwigs, and red ants while predators included centipedes and black ants. Termites and red ants were the predominant arthropod pests and predatory black ants (Hymenoptera: Formicidae) exceeded that of centipedes (Myriapoda: Chilopoda) in the two trial locations. The proportion of unfilled pods was high in the two locations during both years. Generally, the population of centipedes was lower than that of black ants. Damage caused by arthropods to pods or kernels in the sugar-baited plots across the two locations were low and differed significantly from the non-baited plots. Chlorpyrifos-treated plots recorded the highest yield followed by the high rate of sugar baits and the lowest yield being the low rate of sugar among the treatment plots. Data generated in this study have shown that sugar-baits may be effective in suppressing pest populations of peanut and may provide a better refuge for the natural enemies and could be recommended as an option for pest management in peanut production.}, number={2}, journal={African Entomology}, author={Mochiah, M. B. and Owusu-Akyaw, M. and Bolfrey-Arku, G. and Osei, K. and Lamptey, J. N. L. and Adama, I. and Amoabeng, B. W. and Brandenburg, R. L. and Jordan, D. L.}, year={2013}, pages={267–272} } @article{chandi_milla-lewis_jordan_york_burton_zuleta_whitaker_culpepper_2013, title={Use of AFLP Markers to Assess Genetic Diversity in Palmer Amaranth (Amaranthus palmeri) Populations from North Carolina and Georgia}, volume={61}, ISSN={["1550-2759"]}, DOI={10.1614/ws-d-12-00053.1}, abstractNote={Glyphosate-resistant Palmer amaranth is a serious problem in southern cropping systems. Much phenotypic variation is observed in Palmer amaranth populations with respect to plant growth and development and susceptibility to herbicides. This may be related to levels of genetic diversity existing in populations. Knowledge of genetic diversity in populations of Palmer amaranth may be useful in understanding distribution and development of herbicide resistance. Research was conducted to assess genetic diversity among and within eight Palmer amaranth populations collected from North Carolina and Georgia using amplified fragment length polymorphism (AFLP) markers. Pair-wise genetic similarity (GS) values were found to be relatively low, averaging 0.34. The highest and the lowest GS between populations were 0.49 and 0.24, respectively, while the highest and the lowest GS within populations were 0.56 and 0.36, respectively. Cluster and principal coordinate (PCO) analyses grouped individuals mostly by population (localized geographic region) irrespective of response to glyphosate or gender of individuals. Analysis of molecular variance (AMOVA) results when populations were nested within states revealed significant variation among and within populations within states while variation among states was not significant. Variation among and within populations within state accounted for 19 and 77% of the total variation, respectively, while variation among states accounted for only 3% of the total variation. The within population contribution towards total variation was always higher than among states and among populations within states irrespective of response to glyphosate or gender of individuals. These results are significant in terms of efficacy of similar management approaches both in terms of chemical and biological control in different areas infested with Palmer amaranth.}, number={1}, journal={WEED SCIENCE}, publisher={Weed Science Society}, author={Chandi, Aman and Milla-Lewis, Susana R. and Jordan, David L. and York, Alan C. and Burton, James D. and Zuleta, M. Carolina and Whitaker, Jared R. and Culpepper, A. Stanley}, year={2013}, pages={136–145} } @article{prince_shaw_givens_owen_weller_young_wilson_jordan_2012, title={Benchmark Study: I. Introduction, Weed Population, and Management Trends from the Benchmark Survey 2010}, volume={26}, ISSN={["1550-2740"]}, DOI={10.1614/wt-d-11-00157.1}, abstractNote={Almost 1,650 corn, cotton, and soybean growers in 22 states participated in a 2010 telephone survey to determine their attitudes with regard to which weed species were most problematic in glyphosate-resistant (GR) crop production systems for corn, cotton, and soybean. The survey is a follow-up to a previous 2005 to 2006 survey that utilized a smaller set of growers from fewer states. In general, growers continued to estimate weed populations as low and few challenges have been created following adoption of GR cropping systems. Pigweed and foxtail species were dominant overall, whereas other species were more commodity and state specific. Corn, cotton, and soybean growers cited velvetleaf, annual morningglory, and waterhemp, respectively, as predominant weeds. Growers in the South region were more likely to report pigweed and waterhemp (Amaranthus spp.), whereas growers in the East and West reported horseweed. When growers were asked with which GR weeds they had experienced personally, horseweed was reported in all regions, but growers in the South more frequently reported pigweed, whereas growers in the East and West regions more frequently reported waterhemp. Comparisons with the previous 2005 survey indicated that more growers believed they were experiencing GR weeds and were more aware of specific examples in their state. In particular, the Amaranthus complex was of greatest concern in continuously cropped soybean and cotton.}, number={3}, journal={WEED TECHNOLOGY}, author={Prince, Joby M. and Shaw, David R. and Givens, Wade A. and Owen, Micheal D. K. and Weller, Stephen C. and Young, Bryan G. and Wilson, Robert G. and Jordan, David L.}, year={2012}, pages={525–530} } @article{prince_shaw_givens_newman_owen_weller_young_wilson_jordan_2012, title={Benchmark Study: II. A 2010 Survey to Assess Grower Awareness of and Attitudes toward Glyphosate Resistance}, volume={26}, ISSN={["0890-037X"]}, DOI={10.1614/wt-d-11-00091.1}, abstractNote={A 2010 survey of 1,299 corn, cotton, and soybean growers was conducted to determine their attitudes and awareness regarding glyphosate-resistant (GR) weeds and resultant implications on weed management practices. An additional 350 growers included in the current study participated in a 2005 survey, and these answers were compared across time so that cross-sectional and longitudinal comparisons of responses could be made. Most growers surveyed in 2010 were aware of the potential for weeds to evolve resistance to glyphosate; however, many growers were not aware of glyphosate resistance in specific weeds in their county or state. Growers in the South were different from growers in other geographic regions and were significantly more aware of local cases of GR weeds. Awareness of GR weeds did not increase appreciably from 2005 to 2010, but the percentage who reported GR weeds as problematic was significantly higher. Grower reports of GR weeds on-farm in 2010 were up considerably from 2005, with growers in the South reporting significantly more instances than growers in other regions. Growers in the South were also more likely to consider glyphosate resistance a serious problem. Overall, 30% of growers did not consider GR weeds to be a problem. It appears that most growers received information about glyphosate resistance from farm publications, although in the South this percentage was less than for other geographic regions. Growers in the South received more information from universities and extension sources.}, number={3}, journal={WEED TECHNOLOGY}, author={Prince, Joby M. and Shaw, David R. and Givens, Wade A. and Newman, Michael E. and Owen, Micheal D. K. and Weller, Stephen C. and Young, Bryan G. and Wilson, Robert G. and Jordan, David L.}, year={2012}, pages={531–535} } @article{prince_shaw_givens_newman_owen_weller_young_wilson_jordan_2012, title={Benchmark Study: III. Survey on Changing Herbicide Use Patterns in Glyphosate-Resistant Cropping Systems}, volume={26}, ISSN={["0890-037X"]}, DOI={10.1614/wt-d-11-00093.1}, abstractNote={Approximately 1,300 growers from 22 states were surveyed during 2010 to determine herbicide use. Cropping systems included continuous glyphosate-resistant corn, cotton, and soybean, and various combinations of these crops and rotations with non–glyphosate-resistant crops. The most commonly used herbicide for both fall and spring applications was glyphosate followed by synthetic auxin herbicides. Herbicide application in spring was favored over application in the fall. The percentage of growers in a glyphosate-only system was as high as 69% for some cropping systems. Excluding glyphosate, the most frequently used herbicides included photosystem II, mitotic, and protoporphyrinogen oxidase inhibitors. A higher percentage of growers integrated herbicides other than glyphosate during 2010 compared with 2005. Extensive educational efforts have promoted resistance management by increasing the diversity of herbicides in glyphosate-resistant cropping systems. However, a considerable percentage of growers continued use of only glyphosate from the period of 2005 to 2010, and this practice most likely will continue to exert a high level of selection for evolved glyphosate-resistant weed species.}, number={3}, journal={WEED TECHNOLOGY}, author={Prince, Joby M. and Shaw, David R. and Givens, Wade A. and Newman, Michael E. and Owen, Micheal D. K. and Weller, Stephen C. and Young, Bryan G. and Wilson, Robert G. and Jordan, David L.}, year={2012}, pages={536–542} } @article{prince_shaw_givens_owen_weller_young_wilson_jordan_2012, title={Benchmark Study: IV. Survey of Grower Practices for Managing Glyphosate-Resistant Weed Populations}, volume={26}, ISSN={["0890-037X"]}, DOI={10.1614/wt-d-11-00094.1}, abstractNote={In 2010, a grower survey was administered to 1,299 growers in 22 states to determine changes in weed management in the United States from 2006 to 2009. The majority of growers had not changed weed management practices in the previous 3 yr; however, 75% reported using weed management practices targeted at glyphosate-resistant (GR) weeds. Growers were asked to rate their efforts at controlling GR weeds and rate the effectiveness of various practices for controlling/preventing GR weeds regardless of whether they were personally using them. Using the herbicide labeled rate, scouting fields, and rotating crops were among the practices considered by growers as most effective in managing GR weeds. Sixty-seven percent of growers reported effective management of GR weeds. Between the 2005 and 2010 Benchmark surveys, the frequency of growers using specific actions to manage GR weeds increased markedly. Although the relative effectiveness of practices, as perceived by growers, remained the same, the effectiveness rating of tillage and the use of residual and POST herbicides increased.}, number={3}, journal={WEED TECHNOLOGY}, author={Prince, Joby M. and Shaw, David R. and Givens, Wade A. and Owen, Micheal D. K. and Weller, Stephen C. and Young, Bryan G. and Wilson, Robert G. and Jordan, David L.}, year={2012}, pages={543–548} } @article{riar_webster_brecke_jordan_burton_telenko_rufty_2012, title={Benghal Dayflower (Commelina benghalensis) Seed Viability in Soil}, volume={60}, ISSN={["0043-1745"]}, DOI={10.1614/ws-d-12-00047.1}, abstractNote={Benghal dayflower is an exotic weed species in the United States that is a challenge to manage in agricultural fields. Research was conducted in North Carolina, Georgia, and Florida to evaluate the longevity of buried Benghal dayflower seeds. Seeds were buried in the field for 2 to 60 mo at a depth of 20 cm in mesh bags containing soil native to each area. In North Carolina, decline of Benghal dayflower seed viability was described by a sigmoidal regression model, with seed size having no effect on viability. Seed viability at the initiation of the study was 81%. After burial, viability declined to 51% after 24 mo, 27% after 36 mo, and < 1% after 42 mo. In Georgia, initial seed viability averaged 86% and declined to 63 and 33% at 12 and 24 mo, respectively. Burial of 36 mo or longer reduced seed viability to < 2%. The relationship between Benghal dayflower seed viability and burial time was described by a sigmoidal regression model. In Florida, there was greater variability in Benghal dayflower seed viability than there was at the other locations. Seed viability at the first sampling date after 2 mo of burial was 63%. Although there were fluctuations during the first 24 mo, the regression model indicated approximately 60% of seed remained viable. After 34 mo of burial, seed viability was reduced to 46% and then rapidly fell to 7% at 39 mo, which was consistent with the decrease in seed viability at the other locations. Although there is a physical dormancy imposed by the seed coat of Benghal dayflower, which has been detected in previous studies, it appears that a decline in buried seed viability to minimal levels occurs within 39 to 48 mo in the southeastern United States, suggesting that management programs must prevent seed production for at least four growing seasons to severely reduce the Benghal dayflower soil seedbank.}, number={4}, journal={WEED SCIENCE}, author={Riar, Mandeep K. and Webster, Theodore M. and Brecke, Barry J. and Jordan, David L. and Burton, Michael G. and Telenko, Darcy P. and Rufty, Thomas W.}, year={2012}, pages={589–592} } @article{chahal_jordan_shew_brandenburg_york_burton_danehower_2012, title={Interactions of agrochemicals applied to peanut; part 1: Effects on herbicides}, volume={41}, ISSN={0261-2194}, url={http://dx.doi.org/10.1016/j.cropro.2012.05.014}, DOI={10.1016/j.cropro.2012.05.014}, abstractNote={Numerous agrochemicals are applied in peanut production systems. Field and laboratory experiments were conducted in North Carolina to characterize biological and physicochemical interactions when the herbicides clethodim, imazapic, imazethapyr, lactofen, sethoxydim, and 2,4-DB were applied in combination with adjuvants, fungicides, insecticides, and micronutrients. A wide range of interactions was noted when comparing across herbicides, weed species, and agrochemical combinations. There was little consistency across weed species for a herbicide or across herbicides for a weed species when comparing significant main effects and interactions. In most instances, when compared with the standard herbicide treatment and adjuvant applied alone, herbicide efficacy was not affected in the presence of other agrochemicals. Changes in solution pH and formation of precipitates varied according to the herbicide combinations used. Boron, manganese, and 2,4-DB often caused dramatic changes in solution pH.}, journal={Crop Protection}, publisher={Elsevier BV}, author={Chahal, Gurinderbir S. and Jordan, David L. and Shew, Barbara B. and Brandenburg, Rick L. and York, Alan C. and Burton, James D. and Danehower, David}, year={2012}, month={Nov}, pages={134–142} } @article{chahal_jordan_shew_brandenburg_burton_danehower_york_2012, title={Interactions of agrochemicals applied to peanut; part 2: Effects on fungicides}, volume={41}, ISSN={0261-2194}, url={http://dx.doi.org/10.1016/j.cropro.2012.05.008}, DOI={10.1016/j.cropro.2012.05.008}, abstractNote={Field and laboratory experiments were conducted during 2008 and 2009 to study biological and physicochemical compatibility when fungicides were applied in combination with herbicides, insecticides, and micronutrients for the control of leaf spot disease and Sclerotinia blight. In both years, the program with three fungicide sprays was more effective in preventing canopy defoliation caused by early and late leaf spot disease than single fungicide spray irrespective of agrochemical combinations. Although several interactions were noted among agrochemical combinations, most combinations did not affect fungicide efficacy against canopy defoliation or Sclerotinia blight. In some instances, fungicide combinations protected peanut more effectively from canopy defoliation or Sclerotinia blight than standard fungicide treatment. Regardless of the other agrochemicals applied, boscalid was more effective than fluazinam in controlling Sclerotinia blight. Boscalid, boron, clethodim plus crop oil concentrate, chlorothalonil plus tebuconazole, manganese, and 2,4-DB had large effects on solution pH, whereas fluazinam, lambda-cyhalothrin, and pyraclostrobin had little effect on solution pH. Precipitates formed with all fungicide combinations and in most cases permanent precipitates were formed.}, journal={Crop Protection}, publisher={Elsevier BV}, author={Chahal, Gurinderbir S. and Jordan, David L. and Shew, Barbara B. and Brandenburg, Rick L. and Burton, James D. and Danehower, David and York, Alan C.}, year={2012}, month={Nov}, pages={143–149} } @article{chahal_jordan_brandenburg_shew_burton_danehower_york_2012, title={Interactions of agrochemicals applied to peanut; part 3: Effects on insecticides and prohexadione calcium}, volume={41}, ISSN={0261-2194}, url={http://dx.doi.org/10.1016/j.cropro.2012.05.006}, DOI={10.1016/j.cropro.2012.05.006}, abstractNote={A wide range of agrochemicals can be applied in a peanut production system to control various stresses and manage crop growth and development. Field and laboratory experiments were conducted in North Carolina to define biological and physicochemical interactions when insecticides (fenpropathrin and lambda-cyhalothrin) or plant growth regulator (prohexadione calcium) were applied in combination with other agrochemicals including fungicides, herbicides, and micronutrients. Fenpropathrin or lambda-cyhalothrin combinations did not injure peanut in 2008 and 2009. Two sprays of prohexadione calcium improved row visibility and reduced main stem height compared with one prohexadione calcium spray irrespective of agrochemical combinations. In many instances, applying prohexadione calcium with other agrochemicals resulted in lower main stem height compared to prohexadione calcium alone. In one of the experiments, prohexadione calcium with prothioconazole plus tebuconazole lowered fall army worm population compared with prohexadione calcium alone. Addition of boron, manganese, and 2,4-DB to fenpropathrin, lambda-cyhalothrin, and prohexadione calcium combinations changed solution pH dramatically. Prohexadione calcium had the least effect on pH of the carrier.}, journal={Crop Protection}, publisher={Elsevier BV}, author={Chahal, Gurinderbir S. and Jordan, David L. and Brandenburg, Rick L. and Shew, Barbara B. and Burton, James D. and Danehower, David and York, Alan C.}, year={2012}, month={Nov}, pages={150–157} } @article{vann_fisher_jordan_hardy_smith_stewart_2012, title={THE EFFECT OF POTASSIUM RATE ON THE YIELD AND QUALITY OF FLUE-CURED TOBACCO (NICOTIANA TABACUM L.)}, volume={49}, DOI={10.3381/12-019r.1}, abstractNote={Research was conducted at 2 locations in 2009 and 2010 to determine the effect of potassium rate on the yield and quality of flue-cured tobacco. Treatments included 8 rates of potassium from sulfate of potash magnesia (K-Mag, 0–0–22): 0, 84, 112, 140, 168, 196, 224, and 252 kg K2O ha−1. A complete (N–P–K) fertilizer that supplied 134 kg K2O ha−1 was also included as a control treatment. All fertilizer was applied in a single band application within 10 days after transplanting. Yield was measured and samples were assigned an official U.S. Department of Agriculture (USDA) grade. Crop value was determined based on yield and grade. Tissue samples were collected throughout the season at 3 separate times: at layby, at topping, and after curing. Tissue samples were analyzed for total alkaloid and reducing sugar content as well as N, P, K, and Mg content at North Carolina State University. Soil samples were also collected at transplanting, which corresponded with potassium fertilizer application, and were analyze...}, journal={Tobacco Science}, publisher={Tobacco Science}, author={Vann, M. C. and Fisher, L. R. and Jordan, D. L. and Hardy, D. H. and Smith, W. D. and Stewart, A. M.}, year={2012}, month={Jan}, pages={14–20} } @article{grichar_jordan_prostko_2012, title={Weed control and peanut (Arachis hypogaea L.) response to formulations of imazapic}, volume={36}, ISSN={["0261-2194"]}, DOI={10.1016/j.cropro.2012.01.017}, abstractNote={Field studies were conducted from 2006 to 2008 in the peanut (Arachis hypogaea) growing regions of Georgia, North Carolina, and Texas to ascertain two formulations of imazapic marketed as formulation-1 (Cadre®) and formulation-2 (Impose®). Both formulations controlled Acanthospermum hispidum, Eclipta prostrate, Richardia scabra, Verbesina encelioides, Amaranthus palmeri, Ipomoea lacunosa, Sida spinosa, Cucumis melo, Urochloa texana, Cyperus rotundus, and Cyperus esculentus at least 70% in most instances. Ambrosia artemisiifolia and Trianthema portulacastrum control was poor (>70%). Neither formulation of imazapic alone injured peanut in south Texas; however, in Georgia peanut injury ranged from 3 to 8% and in North Carolina injury was 8–20% when rated up to 27 d after herbicide application. Imazapic, regardless of formulation, applied with bentazon injured peanut 5–20% in Georgia and North Carolina but not in Texas. Either formulation of imazapic plus paraquat injured peanut 15–30% in Georgia, 8–17% in Texas, and 28–48% in North Carolina. Imazapic, regardless of formulation, in combination with paraquat reduced yield compared with imazapic alone at one of four locations.}, journal={CROP PROTECTION}, author={Grichar, W. J. and Jordan, D. L. and Prostko, E. P.}, year={2012}, month={Jun}, pages={31–36} } @article{owen_young_shaw_wilson_jordan_dixon_weller_2011, title={Benchmark study on glyphosate-resistant crop systems in the United States. Part 2: Perspectives}, volume={67}, ISSN={["1526-4998"]}, DOI={10.1002/ps.2159}, abstractNote={AbstractA six‐state, 5 year field project was initiated in 2006 to study weed management methods that foster the sustainability of genetically engineered (GE) glyphosate‐resistant (GR) crop systems. The benchmark study field‐scale experiments were initiated following a survey, conducted in the winter of 2005–2006, of farmer opinions on weed management practices and their views on GR weeds and management tactics. The main survey findings supported the premise that growers were generally less aware of the significance of evolved herbicide resistance and did not have a high recognition of the strong selection pressure from herbicides on the evolution of herbicide‐resistant (HR) weeds. The results of the benchmark study survey indicated that there are educational challenges to implement sustainable GR‐based crop systems and helped guide the development of the field‐scale benchmark study. Paramount is the need to develop consistent and clearly articulated science‐based management recommendations that enable farmers to reduce the potential for HR weeds. This paper provides background perspectives about the use of GR crops, the impact of these crops and an overview of different opinions about the use of GR crops on agriculture and society, as well as defining how the benchmark study will address these issues. Copyright © 2011 Society of Chemical Industry}, number={7}, journal={PEST MANAGEMENT SCIENCE}, author={Owen, Micheal D. K. and Young, Bryan G. and Shaw, David R. and Wilson, Robert G. and Jordan, David L. and Dixon, Philip M. and Weller, Stephen C.}, year={2011}, month={Jul}, pages={747–757} } @article{shaw_owen_dixon_weller_young_wilson_jordan_2011, title={Benchmark study on glyphosate-resistant cropping systems in the United States. Part 1: Introduction to 2006-2008}, volume={67}, ISSN={["1526-498X"]}, DOI={10.1002/ps.2160}, abstractNote={AbstractGlyphosate‐resistant (GR) crop technology has dramatically impacted agriculture. The adoption of GR systems in canola, maize, cotton, soybean and sugar beets has been widespread in the United States. However, weed scientists are concerned that growers' current herbicide programs and weed management tactics will affect their sustainability and effectiveness. Without proper management, the potential for weed populations to express a high degree of resistance to glyphosate will adversely impact the utility of glyphosate. In 2005, weed scientists from six universities initiated a long‐term research study to assess the sustainability of GR technology. This paper introduces five other articles in this series. Over 150 fields of at least 10 ha were selected to participate in a long‐term field‐scale study, and each field was split in half. On one‐half the grower continued using the current weed management program; on the other half the grower used academic‐recommended herbicide resistance best management practices. Field data were collected in 2006–2008 to determine the impact of the two weed management programs on weed populations, diversity, seedbank, crop yields and economic returns. This long‐term study will provide invaluable data for determining the sustainability and profitability of diversified weed management programs designed to lower the risk of evolving weed resistance to glyphosate. Copyright © 2011 Society of Chemical Industry}, number={7}, journal={PEST MANAGEMENT SCIENCE}, author={Shaw, David R. and Owen, Micheal D. K. and Dixon, Philip M. and Weller, Stephen C. and Young, Bryan G. and Wilson, Robert G. and Jordan, David L.}, year={2011}, month={Jul}, pages={741–746} } @article{givens_shaw_newman_weller_young_wilson_owen_jordan_2011, title={Benchmark study on glyphosate-resistant cropping systems in the United States. Part 3: Grower awareness, information sources, experiences and management practices regarding glyphosate-resistant weeds}, volume={67}, ISSN={["1526-4998"]}, DOI={10.1002/ps.2178}, abstractNote={AbstractBACKGROUND: A survey was conducted with nearly 1200 growers in US states (Illinois, Indiana, Iowa, Mississippi, Nebraska and North Carolina) in 2005 with the objective in part of determining the awareness of the potential for development of glyphosate resistance, the experience with glyphosate‐resistant (GR) weeds and the sources of information that growers had utilized for information on glyphosate resistance. Growers were asked a series of questions to determine the level of glyphosate resistance awareness and to list the sources of information used to learn about glyphosate resistance issues.RESULTS: The majority of the growers (88%) were aware of a weed's potential to evolve resistance to herbicide, while 44% were aware of state‐specific documented cases of GR weeds, and 15% reported having had personal experience with GR weeds. Among sources of information concerning glyphosate resistance issues, farm publications, dealers/retailers and university/extension were the most frequent responses (41, 17 and 14% respectively). Based on a 1‐10 effectiveness scale, growers ranked tillage the least effective practice (5.5) and using the correct label rates of herbicides at the proper timing for the size and type of weeds present the most effective practice (8.6) with respect to how effectively the practices mitigated the evolution of GR weeds.CONCLUSION: Results from this survey can be used by researchers, extension specialists and crop advisors further to bridge the information gap between growers and themselves and better to disseminate information concerning glyphosate resistance and glyphosate resistance management practices through more targeted information and information delivery methods. Copyright © 2011 Society of Chemical Industry}, number={7}, journal={PEST MANAGEMENT SCIENCE}, author={Givens, Wade A. and Shaw, David R. and Newman, Michael E. and Weller, Stephen C. and Young, Bryan G. and Wilson, Robert G. and Owen, Micheal D. K. and Jordan, David L.}, year={2011}, month={Jul}, pages={758–770} } @article{wilson_young_matthews_weller_johnson_jordan_owen_dixon_shaw_2011, title={Benchmark study on glyphosate-resistant cropping systems in the United States. Part 4: Weed management practices and effects on weed populations and soil seedbanks}, volume={67}, ISSN={["1526-4998"]}, DOI={10.1002/ps.2176}, abstractNote={AbstractBACKGROUND: Weed management in glyphosate‐resistant (GR) maize, cotton and soybean in the United States relies almost exclusively on glyphosate, which raises criticism for facilitating shifts in weed populations. In 2006, the benchmark study, a field‐scale investigation, was initiated in three different GR cropping systems to characterize academic recommendations for weed management and to determine the level to which these recommendations would reduce weed population shifts.RESULTS: A majority of growers used glyphosate as the only herbicide for weed management, as opposed to 98% of the academic recommendations implementing at least two herbicide active ingredients and modes of action. The additional herbicides were applied with glyphosate and as soil residual treatments. The greater herbicide diversity with academic recommendations reduced weed population densities before and after post‐emergence herbicide applications in 2006 and 2007, particularly in continuous GR crops.CONCLUSION: Diversifying herbicides reduces weed population densities and lowers the risk of weed population shifts and the associated potential for the evolution of glyphosate‐resistant weeds in continuous GR crops. Altered weed management practices (e.g. herbicides or tillage) enabled by rotating crops, whether GR or non‐GR, improves weed management and thus minimizes the effectiveness of only using chemical tactics to mitigate weed population shifts. Copyright © 2011 Society of Chemical Industry}, number={7}, journal={PEST MANAGEMENT SCIENCE}, author={Wilson, Robert G. and Young, Bryan G. and Matthews, Joseph L. and Weller, Stephen C. and Johnson, William G. and Jordan, David L. and Owen, Micheal D. K. and Dixon, Philip M. and Shaw, David R.}, year={2011}, month={Jul}, pages={771–780} } @article{weirich_shaw_owen_dixon_weller_young_wilson_jordan_2011, title={Benchmark study on glyphosate-resistant cropping systems in the United States. Part 5: Effects of glyphosate-based weed management programs on farm-level profitability}, volume={67}, ISSN={["1526-498X"]}, DOI={10.1002/ps.2177}, abstractNote={AbstractBACKGROUND: Glyphosate‐resistant (GR) crops have changed the way growers manage weeds and implement control strategies. Since the introduction of GR crops, growers in many instances have relied on glyphosate almost exclusively to control a broad spectrum of weeds. This overreliance on glyphosate has resulted in the evolution of glyphosate resistance in some weed species. Growers and scientists are concerned about the sustainability of GR crops and glyphosate. When a grower is making decisions about weed control strategies, economic costs and benefits of the program are primary criteria for selection and implementation. Studies across six states were initiated in 2006 to compare the economics of using a weed resistance best management practice (BMP) system with a grower's standard production system.RESULTS: Resistance BMP systems recommended by university scientists were more costly but provided similar yields and economic returns. Rotation of GR crops resulted in a higher net return (maize and soybean) compared with continuous GR crop (cotton or soybean) or rotating a GR crop with a non‐GR crop (maize).CONCLUSION: Growers can implement weed resistance BMP systems with the confidence that their net returns will be equivalent in the short run, and, in the long term, resistance BMP systems will prevent or delay the evolution of GR weeds in their fields, resulting in substantial savings. Copyright © 2011 Society of Chemical Industry}, number={7}, journal={PEST MANAGEMENT SCIENCE}, author={Weirich, Jason W. and Shaw, David R. and Owen, Micheal D. K. and Dixon, Philip M. and Weller, Stephen C. and Young, Bryan G. and Wilson, Robert G. and Jordan, David L.}, year={2011}, month={Jul}, pages={781–784} } @article{weirich_shaw_coble_owen_dixon_weller_young_wilson_jordan_2011, title={Benchmark study on glyphosate-resistant cropping systems in the United States. Part 6: Timeliness of economic decision-making in implementing weed resistance management strategies}, volume={67}, ISSN={["1526-498X"]}, DOI={10.1002/ps.2175}, abstractNote={AbstractBACKGROUND:The introduction of glyphosate‐resistant (GR) crops in the late 1990s made weed control in maize, cotton and soybean simple. With the rapid adoption of GR crops, many growers began to rely solely on glyphosate for weed control. This eventually led to the evolution of GR weeds. Growers are often reluctant to adopt a weed resistance best management practice (BMP) because of the added cost of additional herbicides to weed control programs which would reduce short‐term revenue. This study was designed to evaluate when a grower that is risk neutral (profit maximizing) or risk averse should adopt a weed resistance BMP.RESULTS:Whether a grower is risk neutral or risk averse, the optimal decision would be to adopt a weed resistance BMP when the expected loss in revenue is greater than 30% and the probability of resistance evolution is 0.1 or greater. However, if the probability of developing resistance increases to 0.3, then the best decision would be to adopt a weed resistance BMP when the expected loss is 10% or greater.CONCLUSION:Given the scenarios analyzed, risk‐neutral or risk‐averse growers should implement a weed resistance BMP with confidence that they have made the right decision economically and avoided the risk of lost revenue from resistance. If the grower wants to continue to see the same level of return, adoption of BMP is required. Copyright © 2011 Society of Chemical Industry}, number={7}, journal={PEST MANAGEMENT SCIENCE}, author={Weirich, Jason W. and Shaw, David R. and Coble, Keith H. and Owen, Micheal D. K. and Dixon, Philip M. and Weller, Stephen C. and Young, Bryan G. and Wilson, Robert G. and Jordan, David L.}, year={2011}, month={Jul}, pages={785–789} } @article{lassiter_jordan_wilkerson_shew_brandenburg_2011, title={Influence of Cover Crops on Weed Management in Strip Tillage Peanut}, volume={25}, ISSN={["0890-037X"]}, DOI={10.1614/wt-d-11-00064.1}, abstractNote={Experiments were conducted in North Carolina during 2005, 2006, and 2007 to determine peanut and weed response when peanut was planted in strip tillage after desiccation of cereal rye, Italian ryegrass, oats, triticale, wheat, and native vegetation by glyphosate and paraquat before planting with three in-season herbicide programs. Control of common ragweed and yellow nutsedge did not differ among cover crop treatments when compared within a specific herbicide program. Applying dimethenamid orS-metolachlor plus diclosulam PRE followed by imazapic POST was more effective than a chloroacetamide herbicide PRE followed by acifluorfen, bentazon, and paraquat POST. Incidence of spotted wilt in peanut (caused by aTospovirus) did not differ when comparing cover crop treatments, regardless of herbicide program. Peanut yield increased in all 3 yr when herbicides were applied POST, compared with clethodim only. Peanut yield was not affected by cover crop treatment. Response to cover crop treatments was comparable, suggesting that growers can select cereal rye, Italian ryegrass, oats, or triticale as an alternative to wheat as a cover crop in peanut systems without experiencing differences associated with in-season weed management.}, number={4}, journal={WEED TECHNOLOGY}, author={Lassiter, Bridget R. and Jordan, David L. and Wilkerson, Gail G. and Shew, Barbara B. and Brandenburg, Rick L.}, year={2011}, pages={568–573} } @article{chandi_york_jordan_beam_2011, title={Resistance to Acetolactate Synthase and Acetyl Co-A Carboxylase Inhibitors in North Carolina Italian Ryegrass (Lolium perenne)}, volume={25}, ISSN={["1550-2740"]}, DOI={10.1614/wt-d-11-00050.1}, abstractNote={Diclofop-resistant Italian ryegrass is widespread in southwestern North Carolina, and growers have resorted to using acetolactate synthase (ALS) inhibitors such as mesosulfuron and pyroxsulam to control this weed in wheat. In the spring of 2007, mesosulfuron failed to control Italian ryegrass in several wheat fields. Seed were collected from six fields in two counties and greenhouse studies were conducted to determine response to mesosulfuron and the acetyl-CoA carboxylase (ACCase) inhibitors diclofop and pinoxaden. All populations were resistant to diclofop and cross-resistant to pinoxaden. Five of the six populations were resistant to diclofop, pinoxaden, and mesosulfuron. An additional study with two biotypes confirmed cross-resistance to the ALS inhibitors imazamox, mesosulfuron, and pyroxsulam. Resistance to mesosulfuron was heritable.}, number={4}, journal={WEED TECHNOLOGY}, author={Chandi, Aman and York, Alan C. and Jordan, David L. and Beam, Josh B.}, year={2011}, pages={659–666} } @article{whitaker_york_jordan_culpepper_2011, title={Weed Management with Glyphosate- and Glufosinate-Based Systems in PHY 485 WRF Cotton}, volume={25}, ISSN={["1550-2740"]}, DOI={10.1614/wt-d-10-00008.1}, abstractNote={Glyphosate-resistant (GR) Palmer amaranth has become a serious pest in parts of the Cotton Belt. Some GR cotton cultivars also contain the WideStrike™ insect resistance trait, which confers tolerance to glufosinate. Use of glufosinate-based management systems in such cultivars could be an option for managing GR Palmer amaranth. The objective of this study was to evaluate crop tolerance and weed control with glyphosate-based and glufosinate-based systems in PHY 485 WRF cotton. The North Carolina field experiment compared glyphosate and glufosinate alone and in mixtures applied twice before four- to six-leaf cotton. Additional treatments included glyphosate and glufosinate mixed withS-metolachlor or pyrithiobac applied to one- to two-leaf cotton followed by glyphosate or glufosinate alone on four- to six-leaf cotton. All treatments received a residual lay-by application. Excellent weed control was observed from all treatments on most weed species. Glyphosate was more effective than glufosinate on glyphosate-susceptible (GS) Palmer amaranth and annual grasses, while glufosinate was more effective on GR Palmer amaranth. Annual grass and GS Palmer amaranth control by glyphosate plus glufosinate was often less than control by glyphosate alone but similar to or greater than control by glufosinate alone, while mixtures were more effective than either herbicide alone on GR Palmer amaranth. Glufosinate caused minor and transient injury to the crop, but no differences in cotton yield or fiber quality were noted. This research demonstrates glufosinate can be applied early in the season to PHY 485 WRF cotton without concern for significant adverse effects on the crop. Although glufosinate is often less effective than glyphosate on GS Palmer amaranth, GR Palmer amaranth can be controlled with well-timed applications of glufosinate. Use of glufosinate in cultivars with the WideStrike trait could fill a significant void in current weed management programs for GR Palmer amaranth in cotton.}, number={2}, journal={WEED TECHNOLOGY}, author={Whitaker, Jared R. and York, Alan C. and Jordan, David L. and Culpepper, A. Stanley}, year={2011}, pages={183–191} } @article{drake_jordan_schroeder-moreno_johnson_heitman_cardoza_brandenburg_shew_corbett_bogle_et al._2010, title={Crop Response following Tall Fescue Sod and Agronomic Crops}, volume={102}, ISSN={0002-1962}, url={http://dx.doi.org/10.2134/agronj2010.0236}, DOI={10.2134/agronj2010.0236}, abstractNote={Sod‐based production systems have been successful in the southeastern and mid‐Atlantic regions of the United States as an alternative to conventional tillage systems. However, research comparing these systems in North Carolina is limited. Therefore, research was conducted at four locations in North Carolina to compare corn (Zea mays L.), cotton (Gossypium hirsutum L.), peanut (Arachis hypogaea L.), and soybean [Glycine max (L.) Merr.] yield when these crops were strip tilled following 4 yr of continuous tall fescue (Shedonorus phoenix Scop.) vs. 4 yr of either corn or cotton grown in no tillage or strip tillage. Cotton yield was higher following tall fescue compared with yield following agronomic crops. In contrast, yield of corn was lower following tall fescue compared with agronomic crops while peanut and soybean yields were not affected by previous cropping history. Additional treatments in peanut included conventional tillage following both cropping systems, and pod yield was lower when peanut was strip tilled into either tall fescue or residue from corn or cotton compared with conventional tillage systems. No major differences in soil bulk density at depths of 0 to 8 cm or 8 to 16 cm were noted when comparing tall fescue or agronomic crops either in strip tillage or nontilled zones. Populations of soil parasitic nematodes were often lower in peanut following tall fescue than when following agronomic crops. These experiments indicate that sod‐based systems may be an effective alternative to reduced tillage systems, especially for cotton. However, yield benefits were not observed for peanut or soybean and corn was negatively affected by tall fescue.}, number={6}, journal={Agronomy Journal}, publisher={Wiley}, author={Drake, W. L. and Jordan, D. L. and Schroeder-Moreno, M. and Johnson, P. D. and Heitman, J. L. and Cardoza, Y. J. and Brandenburg, R. L. and Shew, B. B. and Corbett, T. and Bogle, C. R. and et al.}, year={2010}, month={Nov}, pages={1692–1699} } @article{place_reberg-horton_jordan_2010, title={Interaction of Cultivar, Planting Pattern, and Weed Management Tactics in Peanut}, volume={58}, ISSN={["1550-2759"]}, DOI={10.1614/ws-d-10-00012.1}, abstractNote={Planting peanut in narrow rows for weed control has not been investigated in recently released Virginia market peanut cultivars. Research was conducted in North Carolina from 2007 to 2009 to determine the effect of cultivar, planting pattern, and level of weed management inputs on weed control, peanut yield, and estimated economic return. Experiments consisted of three levels of weed management (clethodim applied POST, cultivation and hand-removal of weeds, and clethodim and appropriate broadleaf herbicides applied POST), three levels of planting pattern (single rows spaced 91 cm apart, standard twin rows spaced 20 cm apart on 91-cm centers, and narrow twin rows consisting of twin rows spaced 20 cm apart on 46-cm centers), and two Virginia cultivars (‘NC 12C’ and ‘VA 98R’). Weed management affected common lambsquarters, common ragweed, eclipta, nodding spurge, pitted morningglory, Texas millet, and yellow nutsedge control, irrespective of cultivar or planting pattern. Cultivar and planting pattern had only minor effects on weed control and interactions of these treatment factors seldom occurred. Weed control achieved with cultivation plus hand-removal was similar to weed management observed with grass and broadleaf herbicide programs. Pod yield did not differ among treatments when broadleaf weeds were the dominant species but did differ when Texas millet was the most prevalent weed. The highest yield with conventional herbicide weed management was in standard twin and narrow twin row planting patterns, although no differences among planting patterns were noted when cultivation and hand-removal were the primary weed management tactics. Differences in estimated economic return were associated with weed species, and interactions of treatment factors varied by year for that parameter.}, number={4}, journal={WEED SCIENCE}, publisher={Cambridge University Press (CUP)}, author={Place, G. T. and Reberg-Horton, S. C. and Jordan, D. L.}, year={2010}, pages={442–448} } @article{whitaker_york_jordan_culpepper_2010, title={Palmer Amaranth (Amaranthus palmeri) Control in Soybean with Glyphosate and Conventional Herbicide Systems}, volume={24}, ISSN={["1550-2740"]}, DOI={10.1614/wt-d-09-00043.1}, abstractNote={Glyphosate typically controls Palmer amaranth very well. However, glyphosate-resistant (GR) biotypes of this weed are present in several southern states, requiring the development of effective alternatives to glyphosate-only management strategies. Field experiments were conducted in seven North Carolina environments to evaluate control of glyphosate-susceptible (GS) and GR Palmer amaranth in narrow-row soybean by glyphosate and conventional herbicide systems. Conventional systems included either pendimethalin orS-metolachlor applied PRE alone or mixed with flumioxazin, fomesafen, or metribuzin plus chlorimuron followed by fomesafen or no herbicide POST.S-metolachlor was more effective at controlling GR and GS Palmer amaranth than pendimethalin; flumioxazin and fomesafen were generally more effective than metribuzin plus chlorimuron. Fomesafen applied POST following PRE herbicides increased Palmer amaranth control and soybean yield compared with PRE-only herbicide systems. Glyphosate alone applied once POST controlled GS Palmer amaranth 97% late in the season. Glyphosate was more effective than fomesafen plus clethodim applied POST. Control of GS Palmer amaranth when treated with pendimethalin orS-metolachlor plus flumioxazin, fomesafen, or metribuzin plus chlorimuron applied PRE followed by fomesafen POST was equivalent to control achieved by glyphosate applied once POST. In fields with GR Palmer amaranth, greater than 80% late-season control was obtained only with systems of pendimethalin orS-metolachlor plus flumioxazin, fomesafen, or metribuzin plus chlorimuron applied PRE followed by fomesafen POST. Systems of pendimethalin orS-metolachlor plus flumioxazin, fomesafen, or metribuzin plus chlorimuron applied PRE without fomesafen POST controlled GR Palmer amaranth less than 30% late in the season. Systems of pendimethalin orS-metolachlor PRE followed by fomesafen POST controlled GR Palmer amaranth less than 60% late in the season.}, number={4}, journal={WEED TECHNOLOGY}, author={Whitaker, Jared R. and York, Alan C. and Jordan, David L. and Culpepper, Stanley}, year={2010}, pages={403–410} } @article{osei_gowen_pembroke_brandenburg_jordan_2010, title={Potential of leguminous cover crops in management of a mixed population of root-knot nematodes (Meloidogyne spp.)}, volume={42}, number={3}, journal={Journal of Nematology}, author={Osei, K. and Gowen, S. R. and Pembroke, B. and Brandenburg, R. L. and Jordan, D. L.}, year={2010}, pages={173–178} } @article{givens_shaw_johnson_weller_young_wilson_owen_jordan_2009, title={A Grower Survey of Herbicide Use Patterns in Glyphosate-Resistant Cropping Systems}, volume={23}, ISSN={["1550-2740"]}, DOI={10.1614/WT-08-039.1}, abstractNote={A telephone survey was conducted with growers in Iowa, Illinois, Indiana, Nebraska, Mississippi, and North Carolina to discern the utilization of the glyphosate-resistant (GR) trait in crop rotations, weed pressure, tillage practices, herbicide use, and perception of GR weeds. This paper focuses on survey results regarding herbicide decisions made during the 2005 cropping season. Less than 20% of the respondents made fall herbicide applications. The most frequently used herbicides for fall applications were 2,4-D and glyphosate, and these herbicides were also the most frequently used for preplant burndown weed control in the spring. Atrazine and acetochlor were frequently used in rotations containing GR corn. As expected, crop rotations using a GR crop had a high percentage of respondents that made one to three POST applications of glyphosate per year. GR corn, GR cotton, and non-GR crops had the highest percentage of growers applying non-glyphosate herbicides during the 2005 growing season. A crop rotation containing GR soybean had the greatest negative impact on non-glyphosate use. Overall, glyphosate use has continued to increase, with concomitant decreases in utilization of other herbicides.}, number={1}, journal={WEED TECHNOLOGY}, author={Givens, Wade A. and Shaw, David R. and Johnson, William G. and Weller, Stephen C. and Young, Bryan G. and Wilson, Robert G. and Owen, Micheal D. K. and Jordan, David}, year={2009}, pages={156–161} } @article{drake_jordan_lassiter_johnson_brandenburg_royals_2009, title={Peanut Cultivar Response to Damage from Tobacco Thrips and Paraquat}, volume={101}, ISSN={["1435-0645"]}, DOI={10.2134/agronj2009.0185}, abstractNote={Virginia market‐type peanut cultivars in North Carolina vary in the number of days following emergence required to reach optimum maturity, and concern over cultivar response to interactions of tobacco thrips (Frankliniella fusca Hinds) damage in absence of in‐furrow insecticide and injury from paraquat exist with respect to cultivar selection. Experiments were conducted during 2007 and 2008 to determine if cultivars vary in response to interactions of the insecticide aldicarb (no aldicarb or aldicarb applied in the seed furrow at planting) and the herbicide paraquat (no paraquat or paraquat applied 24 to 28 d after peanut emergence, DAE). The cultivar VA 98R expressed more damage from tobacco thrips than the cultivars Gregory, Perry, or Phillips. Although vegetative growth parameters varied among cultivar, aldicarb, and paraquat treatments, pod yield and market grade characteristics were not affected by the interaction of experiment, cultivar, aldicarb, and paraquat or the interaction of cultivar, aldicarb, and paraquat. Damage from tobacco thrips in absence of aldicarb affected pod yield more than injury from paraquat. The combination of tobacco thrips damage in absence of aldicarb and injury from paraquat lowered pod yield compared with aldicarb‐treated peanut either with or without paraquat regardless of cultivar. These data suggest that recommendations on use of aldicarb for tobacco thrips control or paraquat for early season weed control should not vary based on cultivar selection when considering pod yield and market grade characteristics.}, number={6}, journal={AGRONOMY JOURNAL}, author={Drake, Wendy L. and Jordan, David L. and Lassiter, Bridget R. and Johnson, P. Dewayne and Brandenburg, Rick L. and Royals, Brian M.}, year={2009}, pages={1388–1393} } @article{jordan_lancaster_lanier_lassiter_johnson_2009, title={Peanut and Eclipta (Eclipta prostrata) Response to Flumioxazin}, volume={23}, ISSN={["0890-037X"]}, DOI={10.1614/WT-08-050.1}, abstractNote={Research was conducted in North Carolina to determine peanut response to flumioxazin as influenced by rate and timing of application and cultivar. Delaying application of flumioxazin from 1 d after planting until peanut emergence increased injury regardless of rate. The Virginia market-type cultivar ‘NC-V 11’ was injured more by flumioxazin than the cultivars ‘Gregory’ or ‘Perry’. However, pod yield was not affected by flumioxazin even though significant injury was observed early in the season regardless of flumioxazin rate, application timing, or cultivar. Diclosulam was more effective than flumioxazin in controlling eclipta when these herbicides were applied PRE with metolachlor or following pendimethalin PPI. However, control by flumioxazin prevented yield loss when compared with metolachlor alone.}, number={2}, journal={WEED TECHNOLOGY}, author={Jordan, David L. and Lancaster, Sarah H. and Lanier, James E. and Lassiter, Bridget R. and Johnson, P. Dewayne}, year={2009}, pages={231–235} } @article{givens_shaw_kruger_johnson_weller_young_wilson_owen_jordan_2009, title={Survey of Tillage Trends Following the Adoption of Glyphosate-Resistant Crops}, volume={23}, ISSN={["1550-2740"]}, DOI={10.1614/WT-08-038.1}, abstractNote={A phone survey was administered to 1,195 growers in six states (Illinois, Indiana, Iowa, Mississippi, Nebraska, and North Carolina). The survey measured producers' crop history, perception of glyphosate-resistant (GR) weeds, past and present weed pressure, tillage practices, and herbicide use as affected by the adoption of GR crops. This article describes the changes in tillage practice reported in the survey. The adoption of a GR cropping system resulted in a large increase in the percentage of growers using no-till and reduced-till systems. Tillage intensity declined more in continuous GR cotton and GR soybean (45 and 23%, respectively) than in rotations that included GR corn or non-GR crops. Tillage intensity declined more in the states of Mississippi and North Carolina than in the other states, with 33% of the growers in these states shifting to more conservative tillage practices after the adoption of a GR crop. This was primarily due to the lower amount of conservation tillage adoption in these states before GR crop availability. Adoption rates of no-till and reduced-till systems increased as farm size decreased. Overall, producers in a crop rotation that included a GR crop shifted from a relatively more tillage-intense system to reduced-till or no-till systems after implementing a GR crop into their production system.}, number={1}, journal={WEED TECHNOLOGY}, author={Givens, Wade A. and Shaw, David R. and Kruger, Greg R. and Johnson, William G. and Weller, Stephen C. and Young, Bryan G. and Wilson, Robert G. and Owen, Micheal D. K. and Jordan, David}, year={2009}, pages={150–155} } @article{johnson_owen_kruger_young_shaw_wilson_wilcut_jordan_weller_2009, title={US Farmer Awareness of Glyphosate-Resistant Weeds and Resistance Management Strategies}, volume={23}, ISSN={["1550-2740"]}, DOI={10.1614/WT-08-181.1}, abstractNote={A survey of farmers from six U.S. states (Indiana, Illinois, Iowa, Nebraska, Mississippi, and North Carolina) was conducted to assess the farmers' views on glyphosate-resistant (GR) weeds and tactics used to prevent or manage GR weed populations in genetically engineered (GE) GR crops. Only 30% of farmers thought GR weeds were a serious issue. Few farmers thought field tillage and/or using a non-GR crop in rotation with GR crops would be an effective strategy. Most farmers did not recognize the role that the recurrent use of an herbicide plays in evolution of resistance. A substantial number of farmers underestimated the potential for GR weed populations to evolve in an agroecosystem dominated by glyphosate as the weed control tactic. These results indicate there are major challenges that the agriculture and weed science communities must face to implement long-term sustainable GE GR-based cropping systems within the agroecosystem.}, number={2}, journal={WEED TECHNOLOGY}, author={Johnson, William G. and Owen, Micheal D. K. and Kruger, Greg R. and Young, Bryan G. and Shaw, David R. and Wilson, Robert G. and Wilcut, John W. and Jordan, David L. and Weller, Stephen C.}, year={2009}, pages={308–312} } @article{kruger_johnson_weller_owen_shaw_wilcut_jordan_wilson_bernards_young_2009, title={US Grower Views on Problematic Weeds and Changes in Weed Pressure in Glyphosate-Resistant Corn, Cotton, and Soybean Cropping Systems}, volume={23}, ISSN={["1550-2740"]}, DOI={10.1614/WT-08-040.1}, abstractNote={Corn and soybean growers in Illinois, Indiana, Iowa, Mississippi, Nebraska, and North Carolina, as well as cotton growers in Mississippi and North Carolina, were surveyed about their views on changes in problematic weeds and weed pressure in cropping systems based on a glyphosate-resistant (GR) crop. No growers using a GR cropping system for more than 5 yr reported heavy weed pressure. Over all cropping systems investigated (continuous GR soybean, continuous GR cotton, GR corn/GR soybean, GR soybean/non-GR crop, and GR corn/non-GR crop), 0 to 7% of survey respondents reported greater weed pressure after implementing rotations using GR crops, whereas 31 to 57% felt weed pressure was similar and 36 to 70% indicated that weed pressure was less. Pigweed, morningglory, johnsongrass, ragweed, foxtail, and velvetleaf were mentioned as their most problematic weeds, depending on the state and cropping system. Systems using GR crops improved weed management compared with the technologies used before the adoption of GR crops. However, the long-term success of managing problematic weeds in GR cropping systems will require the development of multifaceted integrated weed management programs that include glyphosate as well as other weed management tactics.}, number={1}, journal={WEED TECHNOLOGY}, author={Kruger, Greg R. and Johnson, William G. and Weller, Stephen C. and Owen, Micheal D. K. and Shaw, David R. and Wilcut, John W. and Jordan, David L. and Wilson, Robert G. and Bernards, Mark L. and Young, Bryan G.}, year={2009}, pages={162–166} } @article{shaw_givens_farno_gerard_jordan_johnson_weller_young_wilson_owen_2009, title={Using a Grower Survey to Assess the Benefits and Challenges of Glyphosate-Resistant Cropping Systems for Weed Management in US Corn, Cotton, and Soybean}, volume={23}, ISSN={["1550-2740"]}, DOI={10.1614/WT-08-042.1}, abstractNote={Over 175 growers in each of six states (Illinois, Indiana, Iowa, Mississippi, Nebraska, and North Carolina) were surveyed by telephone to assess their perceptions of the benefits of utilizing the glyphosate-resistant (GR) crop trait in corn, cotton, and soybean. The survey was also used to determine the weed management challenges growers were facing after using this trait for a minimum of 4 yr. This survey allowed the development of baseline information on how weed management and crop production practices have changed since the introduction of the trait. It provided useful information on common weed management issues that should be addressed through applied research and extension efforts. The survey also allowed an assessment of the perceived levels of concern among growers about glyphosate resistance in weeds and whether they believed they had experienced glyphosate resistance on their farms. Across the six states surveyed, producers reported 38, 97, and 96% of their corn, cotton, and soybean hectarage planted in a GR cultivar. The most widely adopted GR cropping system was a GR soybean/non-GR crop rotation system; second most common was a GR soybean/GR corn crop rotation system. The non-GR crop component varied widely, with the most common crops being non-GR corn or rice. A large range in farm size for the respondents was observed, with North Carolina having the smallest farms in all three crops. A large majority of corn and soybean growers reported using some type of crop rotation system, whereas very few cotton growers rotated out of cotton. Overall, rotations were much more common in Midwestern states than in Southern states. This is important information as weed scientists assist growers in developing and using best management practices to minimize the development of glyphosate resistance.}, number={1}, journal={WEED TECHNOLOGY}, author={Shaw, David R. and Givens, Wade A. and Farno, Luke A. and Gerard, Patrick D. and Jordan, David and Johnson, William G. and Weller, Stephen C. and Young, Bryan G. and Wilson, Robert G. and Owen, Michael D. K.}, year={2009}, pages={134–149} } @article{ducar_clewis_wilcut_jordan_brecke_grichar_johnson_wehtje_2009, title={Weed Management Using Reduced Rate Combinations of Diclosulam, Flumioxazin, and Imazapic in Peanut}, volume={23}, ISSN={["1550-2740"]}, DOI={10.1614/WT-07-180.1}, abstractNote={Experiments were conducted during 2000 and 2001 at a total of 13 locations throughout Alabama, Georgia, Florida, North Carolina, and Texas to evaluate efficacy of herbicides at or below the manufacturer's suggested use rate. Herbicide applications included diclosulam and flumioxazin applied PRE alone or followed by imazapic applied early postemergence (EPOST). All possible combinations of diclosulam at 0, 13.5, or 27 g ai/ha and flumioxazin at 0, 53, or 105 g ai/ha applied PRE were included. Imazapic was applied at 35 g ai/ha. Ivyleaf morningglory was controlled more than 87% when imazapic was applied EPOST regardless of PRE herbicide. Pitted morningglory control > 67% was observed with applications of diclosulam (27 g/ha) followed by imazapic, diclosulam (13.5 g/ha) plus flumioxazin (53 g/ha), diclosulam (13.5 g/ha) plus flumioxazin (105 g/ha), and diclosulam (27 g/ha) plus flumioxazin (105 g/ha). Sicklepod was controlled more than 74% with flumioxazin (53 g/ha) followed by imazapic and diclosulam (27 g/ha) plus flumioxazin (105 g/ha) followed by imazapic. Florida beggarweed was controlled more than 84% by all PRE herbicide combinations except flumioxazin (53 g/ha) alone or diclosulam (27 g/ha) alone or with imazapic. Yellow nutsedge was controlled at least 90% with diclosulam at either rate followed by imazapic and by diclosulam plus flumioxazin followed by imazapic regardless of rate. Pod yield was generally higher when herbicides were applied regardless of herbicide combination or rate. Peanut yield was maximized with the lowest rates of flumioxazin or diclosulam PRE followed by imazapic EPOST.}, number={2}, journal={WEED TECHNOLOGY}, author={Ducar, J. Tredaway and Clewis, S. B. and Wilcut, J. W. and Jordan, D. L. and Brecke, B. J. and Grichar, W. J. and Johnson, W. C., III and Wehtje, G. R.}, year={2009}, pages={236–242} } @article{jordan_lancaster_lanier_lassiter_johnson_2009, title={Weed Management in Peanut with Herbicide Combinations Containing Imazapic and Other Pesticides}, volume={23}, ISSN={["1550-2740"]}, DOI={10.1614/WT-08-041.1}, abstractNote={Research was conducted in North Carolina to compare weed control by various rates of imazapic POST alone or following diclosulam PRE. In a second experiment, weed control by imazapic applied POST alone or with acifluoren, diclosulam, or 2,4-DB was compared. In a final experiment, yellow nutsedge control by imazapic alone and with the fungicides azoxystrobin, chlorothalonil, pyraclostrobin, and tebuconazole was compared. Large crabgrass was controlled more effectively by imazapic POST than diclosulam PRE. Common lambsquarters, common ragweed, and eclipta were controlled more effectively by diclosulam PRE than imazapic POST. Nodding spurge was controlled similarly by both herbicides. Few differences in control were noted when comparing imazapic rates after diclosulam PRE. Applying either diclosulam PRE or imazapic POST alone or in combination increased peanut yield over nontreated peanut in five of six experiments. Few differences in pod yield were noted when comparing imazapic rates. Acifluorfen, diclosulam, and 2,4-DB did not affect entireleaf morningglory, large crabgrass, nodding spurge, pitted morningglory, and yellow nutsedge control by imazapic. Eclipta control by coapplication of imazapic and diclosulam exceeded control by imazapic alone. The fungicides azoxystrobin, chlorothalonil, pyraclostrobin, and tebuconazole did not affect yellow nutsedge control by imazapic.}, number={1}, journal={WEED TECHNOLOGY}, author={Jordan, David L. and Lancaster, Sarah H. and Lanier, James E. and Lassiter, Bridget R. and Johnson, P. Dewayne}, year={2009}, pages={6–10} } @article{jordan_barnes_corbett_bogle_johnson_shew_koenning_ye_brandenburg_2008, title={Crop Response to Rotation and Tillage in Peanut-Based Cropping Systems}, volume={100}, ISSN={["1435-0645"]}, DOI={10.2134/agronj2008.0075}, abstractNote={Production of peanut (Arachis hypogaea L.) in reduced tillage systems has increased in the United States during the past decade. However, interactions of tillage system and crop rotation have not been thoroughly investigated for large‐seeded, Virginia market type peanut. Research was conducted at two locations in North Carolina during 1999 to 2006 to compare yield of corn (Zea mays L.), cotton (Gossypium hirsutum L.), and peanut in different rotations planted in conventional and reduced tillage. Crop rotation affected peanut yield but did not affect corn or cotton yield. Increasing the number of times corn, cotton, or a combination of these crops were planted between peanut increased peanut yields. Tillage affected cotton and peanut yield but not in every year or at both locations. Yield was similar in conventional and reduced tillage in 8 of 10 comparisons (cotton) and 6 of 8 comparisons (peanut). Crop rotation and tillage did not interact for visual estimates of plant condition of peanut as a result of disease, soil parasitic nematode populations when peanut was planted during the final year of the experiment, crop yield, cumulative net return over the duration of the experiment, or bulk density in the pegging zone during the final year of the experiment. These data suggest that variation in response to rotation and tillage should be expected based on the crop and edaphic and environmental conditions. However, response to rotation and tillage most likely will be independent.}, number={6}, journal={AGRONOMY JOURNAL}, author={Jordan, David L. and Barnes, J. Steven and Corbett, Tommy and Bogle, Clyde R. and Johnson, P. Dewayne and Shew, Barbara B. and Koenning, Stephen R. and Ye, Weimin and Brandenburg, Rick L.}, year={2008}, pages={1580–1586} } @article{lancaster_jordan_johnson_2008, title={Influence of Graminicide Formulation on Compatibility with Other Pesticides}, volume={22}, ISSN={["1550-2740"]}, DOI={10.1614/WT-07-067.1}, abstractNote={Experiments were conducted from 2003 through 2006 to compare annual grass control by graminicides applied alone or with other pesticides and to determine whether graminicide formulation affected annual grass control and interactions with co-applied pesticides. Formulation and rate had no affect on broadleaf signalgrass or large crabgrass control by clethodim. The efficacy of clethodim in tank mixtures with acifluorfen plus bentazon, bentazon, chlorothalonil, imazapic, pyraclostrobin, or tebuconazole were not affected by clethodim formulation. Broadleaf signalgrass and large crabgrass control by clethodim was slightly reduced by acifluorfen plus bentazon, chlorothalonil, imazapic, and pyraclostrobin, but not by tebuconazole. Chlorothalonil and pyraclostrobin reduced broadleaf signalgrass control with quizalofop-P but did not reduce fall panicum control. Azoxystrobin, propiconazole, and tebuconazole did not affect efficacy of quizalofop-P.}, number={4}, journal={WEED TECHNOLOGY}, author={Lancaster, Sarah H. and Jordan, David L. and Johnson, P. Dewayne}, year={2008}, pages={580–583} } @article{carley_jordan_dharmasri_sutton_brandenburg_burton_2008, title={Peanut response to planting date and potential of canopy reflectance as an indicator of pod maturation}, volume={100}, ISSN={["1435-0645"]}, DOI={10.2134/agronj2006.0352}, abstractNote={Determining when to dig peanut (Arachis hypogea L.) is complicated because of its indeterminate growth habit. Pod mesocarp color is often used an indicator of pod maturation. However, this process is time consuming and is usually based on a relatively small subsample of pods from peanut fields. Research was conducted during 2003–2005 to determine if reflectance of the peanut canopy, using multispectral imaging (350–2500 nm), could be used as an indicator of pod maturation. The cultivars VA 98R and NC‐V 11 were planted beginning in early May through early June during each year with reflectance and the percentage of pods at optimum maturity (percentage of pods with brown or black mesocarp color) determined in mid‐September. The highest yield observed for VA 98R across the 3 yr of the experiment was noted when peanut was planted in mid‐May rather than early or late May or when planted in early June when peanut was dug based on optimum pod maturity using pod mesocarp color. Pod yield for the cultivar NC‐V 11 did not differ when comparing planting dates. For cultivar VA 98R, Pearson's correlations were significant for all bandwidth categories except the normalized difference vegetation index (NDVI) when reflectance was compared with percentage of mature pods. Reflectance for NC‐V 11 was not significant for any of the correlations even though significant differences in the percentage of mature pods were noted in mid September when comparing planting dates. These data suggest that canopy reflectance could potentially aid in predicting pod maturation, but more research is needed to determine feasibility of this approach.}, number={2}, journal={AGRONOMY JOURNAL}, author={Carley, Danesha S. and Jordan, David L. and Dharmasri, L. Cecil and Sutton, Turner B. and Brandenburg, Rick L. and Burton, Michael G.}, year={2008}, pages={376–380} } @article{lancaster_beam_lanier_jordan_johnson_2007, title={Compatibility of diclosulam with postemergence herbicides and fungicides}, volume={21}, ISSN={["0890-037X"]}, DOI={10.1614/WT-07-028.1}, abstractNote={Diclosulam is registered for residual and postemergence control of several broadleaf weeds and suppression of annual sedges in peanut in the southeastern United States. Many producers apply herbicides and other pesticides simultaneously to increase the spectrum of pest control or to increase efficiency of operations. However, compatibility of coapplication of pesticides is a concern. Field trials were conducted to evaluate the compatibility of diclosulam with other herbicides and fungicides. Horseweed control by diclosulam in combination with glyphosate, sulfosate, or paraquat was compared to combinations of these herbicides with flumioxazin, tribenuron plus thifensulfuron, or 2,4-D. All treatments that contained diclosulam controlled horseweed at least 86%. Broadleaf signalgrass control by clethodim and sethoxydim was not affected by diclosulam; however, large crabgrass control was reduced when graminicides were coapplied with diclosulam. Common ragweed control was reduced when diclosulam was applied with chlorothalonil and pyraclostrobin but not by azoxystrobin or tebuconazole.}, number={4}, journal={WEED TECHNOLOGY}, author={Lancaster, Sarah H. and Beam, Joshua B. and Lanier, James E. and Jordan, David L. and Johnson, P. Dewayne}, year={2007}, pages={869–872} } @article{robinson_moffitt_wilkerson_jordan_2007, title={Economics and effectiveness of alternative weed scouting methods in peanut}, volume={21}, ISSN={["1550-2740"]}, DOI={10.1614/WT-05-190.1}, abstractNote={On-farm trials were conducted in 16 North Carolina peanut fields to obtain estimates of scouting times and quality of herbicide recommendations for different weed scouting methods. The fields were monitored for weed species and population density using four scouting methods: windshield (estimate made from the edge of the field), whole-field (estimate based on walk through the field), range (weed densities rated on 1–5 scale at six locations in the field), and counts (weeds estimated by counting at six locations in the field). The herbicide application decision support system (HADSS) was used to determine theoretical net return over herbicide investment and yield loss ($ and %) for each treatment in each field. Three scouts estimated average weed population densities using each scouting method. These values were entered into HADSS to obtain treatment recommendations. Independently collected count data from all three scouts were combined to determine the optimal treatment in each field and the relative ranking of each available treatment. When using the whole-field method, scouts observed a greater number of weed species than when using the other methods. The windshield, whole-field, and range scouting methods tended to overestimate density slightly at low densities and underestimate density substantially at high densities, compared to the count method. The windshield method required the least amount of time to complete (6 min per field), but also resulted in the greatest average loss. Even for this method, recommendations had theoretical net returns within 10% of the return for the optimal treatment 80% of the time. The count method appears to have less economic risk than the windshield, whole-field, and range scouting methods.}, number={1}, journal={WEED TECHNOLOGY}, author={Robinson, Bridget L. and Moffitt, Jodie M. and Wilkerson, Gail G. and Jordan, David L.}, year={2007}, pages={88–96} } @article{wilson_york_jordan_2007, title={Effect of row spacing on weed management in glufosinate-resistant cotton}, volume={21}, ISSN={["0890-037X"]}, DOI={10.1614/WT-06-089.1}, abstractNote={Transgenic, herbicide-resistant cultivars and equipment to spindle-pick 38-cm rows has renewed interest in narrow-row cotton production. Field experiments were conducted at four locations in North Carolina during 2004 and 2005 to evaluate weed management systems in glufosinate-resistant cotton planted in 38- and 97-cm rows. Weeds included broadleaf signalgrass, goosegrass, fall panicum, large crabgrass, Palmer amaranth, smooth pigweed, pitted morningglory, and tall morningglory. Greater than 90% control of annual grasses and Amaranthus spp. in 2004 and Ipomoea spp. in both years was obtained in narrow-row cotton with glufosinate applied early POST (EPOST) and mid-POST (MPOST) to two- and six-leaf cotton, respectively. With good early-season control by glufosinate and rapid canopy closure, there was little benefit from pendimethalin, fluometuron, or pyrithiobac applied PRE, S-metolachlor or pyrithiobac mixed with glufosinate applied MPOST, or trifloxysulfuron applied late POST (LPOST) to 11-leaf cotton in 2004. In 2005, with larger weeds at initial application, glufosinate EPOST and MPOST did not adequately control annual grasses and Amaranthus spp. Pendimethalin PRE increased control to greater than 90% and increased yields 59 to 75%. Pendimethalin PRE followed by S-metolachlor or pyrithiobac mixed with glufosinate at MPOST was no more effective than pendimethalin alone. Without PRE herbicides, trifloxysulfuron applied LPOST increased Amaranthus but not annual grass control. Cotton row spacing had no effect on cotton yield and little effect on weed control. Nomenclature: Fluometuron; S-metolachlor; MSMA; pendimethalin; prometryn; pyrithiobac; trifloxysulfuron; broadleaf signalgrass, Brachiaria platyphylla (Griseb.) Nash BRAPP; fall panicum, Panicum dichotomiflorum Michx. PANDI; goosegrass, Eleusine indica (L.) Gaertn. ELEIN; large crabgrass, Digitaria sanguinalis (L.) Scop. DIGSA; Palmer amaranth, Amaranthus palmeri (S.) Wats. AMAPA; pitted morningglory, Ipomoea lacunosa L. IPOLA; smooth pigweed, Amaranthus hybridus L. AMACH; tall morningglory, Ipomoea purpurea (L.) Roth PHBPU; cotton, Gossypium hirsutum L. ‘FM 958LL’.}, number={2}, journal={WEED TECHNOLOGY}, author={Wilson, David G., Jr. and York, Alan C. and Jordan, David L.}, year={2007}, pages={489–495} } @article{clewis_jordan_spears_wilcut_2007, title={Influence of environmental factors on cutleaf eveningprimrose (Oenothera laciniata) germination, emergence, development, vegetative growth, and control}, volume={55}, ISSN={["1550-2759"]}, DOI={10.1614/WS-06-089}, abstractNote={Abstract Laboratory and greenhouse studies were conducted to determine the effect of temperature, solution pH, water stress, and planting depth on cutleaf eveningprimrose germination and emergence. Field studies were conducted to measure growth parameters of cutleaf eveningprimrose throughout the fall season. When treated with constant temperature, cutleaf eveningprimrose germinated over a range of 15 to 32 C, with the optimum germination occurring at 24 C. Onset, rate, and total germination were greatest in an alternating 20/35 C temperature regime. Germination decreased as solution pH increased, with greatest germination occurring at solution pH of 4. Germination decreased when cutleaf eveningprimrose seed was subjected to increased water stress. Emergence was optimum when seed were buried at depths of 0.5 cm. Germination decreased with increasing burial depth, and no seed emerged from a depth of 10 cm. Cutleaf eveningprimrose control was maximized when 2,4-D was applied in mixture with glyphosate or paraquat. These data suggest that cutleaf eveningprimrose can germinate and gain biomass from early March to late October. These attributes could contribute to poor control before cotton planting if preplant control applications are delayed after early March. Nomenclature: Cutleaf eveningprimrose, Oenothera laciniata Hill OEOLA, cotton, Gossypium hirsutum L}, number={3}, journal={WEED SCIENCE}, author={Clewis, S. B. and Jordan, D. L. and Spears, J. F. and Wilcut, J. W.}, year={2007}, pages={264–272} } @article{herbert_malone_aref_brandenburg_jordan_royals_johnson_2007, title={Role of insecticides in reducing thrips injury to plants and incidence of tomato spotted wilt virus in virginia market-type peanut}, volume={100}, ISSN={["0022-0493"]}, DOI={10.1603/0022-0493(2007)100[1241:ROIIRT]2.0.CO;2}, abstractNote={Abstract Tomato spotted wilt virus (family Bunyaviridae, genus Tospovirus, TSWV), transmitted by many thrips species, is a devastating pathogen of peanut, Arachis hypogaea L. TSWV has become a serious problem in the Virginia/Carolina peanut-growing region of the United States. During 2002, TSWV was present in 47% of the North Carolina hectarage and caused a 5% yield reduction in Virginia. Factors influencing levels of TSWV in runner market-type peanut cultivars, which are primarily grown in Alabama, Flordia, Georgia, and Texas, have been integrated into an advisory to help those peanut growers reduce losses. An advisory based on the southeast runner market-type version is currently under development for virginia market-type peanut cultivars that are grown primarily in the Virginia/Carolina region. A version based on preliminary field experiments was released in 2003. One factor used in both advisories relates to insecticide use to reduce the vector populations and disease incidence. This research elucidated the influence of insecticides on thrips populations, thrips plant injury, incidence of TSWV, and pod yield in virginia market-type peanut. Eight field trials from 2003 to 2005 were conducted at two locations. In-furrow application of aldicarb and phorate resulted in significant levels of thrips control, significant reductions in thrips injury to seedlings, reduced incidence of TSWV, and significant increases in pod yield. Foliar application of acephate after aldicarb or phorate applied in the seed furrow further reduced thrips plant injury and incidence of TSWV and improved yield. These findings will be used to improve the current virginia market-type TSWV advisory.}, number={4}, journal={JOURNAL OF ECONOMIC ENTOMOLOGY}, author={Herbert, D. Ames, Jr. and Malone, S. and Aref, S. and Brandenburg, R. L. and Jordan, D. L. and Royals, B. M. and Johnson, P. D.}, year={2007}, month={Aug}, pages={1241–1247} } @article{lancaster_beam_lanier_jordan_johnson_2007, title={Weed and peanut (Arachis hypogaea) response to diclosularn applied POST}, volume={21}, ISSN={["0890-037X"]}, DOI={10.1614/WT-06-151.1}, abstractNote={Diclosulam is generally applied either PPI or PRE to peanut to control certain broadleaf weeds and suppress sedges. Research was conducted to determine efficacy and peanut response to POST applications of diclosulam at 9, 13, 18, and 27 g ai/ha. Efficacy of diclosulam was affected by application rate and environment. Common ragweed control ranged from 60 to 100%, entireleaf morningglory control from 56 to 100%, marestail control from 78 to 85%, and nodding spurge from 50 to 97%. Smooth pigweed and common lambsquarters were both controlled less than 35%. Diclosulam controlled yellow nutsedge and eclipta less than 70 and 80%, respectively. In separate experiments, diclosulam and imazapic controlled dogfennel more effectively than acifluorfen, bentazon, imazethapyr, lactofen, paraquat, or 2,4-DB. Visual estimates of peanut injury were 15% or less for all rates during both years. Peanut yield ranged from 3,340 to 3,730 kg/ha in 2002 and 5,230 to 5,820 kg/ha in 2003. Foliar injury and peanut pod yield were influenced by diclosulam rate, although no clear relation was evident. Cultivar and diclosulam rate did not interact with respect to visual injury or pod yield. Nomenclature: Acifluorfen, bentazon, diclosulam, imazapic, imazethapyr, lactofen, paraquat, 2,4-DB, common lambsquarters, Chenopodium album L. CHEAL, common ragweed, Ambrosia artemisiifolia L. AMBEL, dogfennel, Eupatorium capillifolium (Lam.) Small EUPCP, eclipta, Eclipta prostrata L. ECLAL, entireleaf morningglory, Ipomoea hederaceae var integriscula Gray IPOHG, marestail, Conyza canadensis (L.) Cronq. ERICA, nodding spurge, Chamaesyce nutans (Lag.) Small EPHNU, smooth pigweed, Amaranthus hybridus L. AMACH, yellow nutsedge, Cyperus esculentus L. #CYPES, peanut, Arachis hypogaea L. ‘NC-V 11’ ‘Perry’}, number={3}, journal={WEED TECHNOLOGY}, author={Lancaster, Sarah H. and Beam, Joshua B. and Lanier, James E. and Jordan, David L. and Johnson, P. Dewayne}, year={2007}, pages={618–622} } @article{clewis_everman_jordan_wilcut_2007, title={Weed management in north Carolina peanuts (Arachis hypogaea) with s-metolachlor, diclosulam, flumioxazin, and sulfentrazone systems}, volume={21}, ISSN={["1550-2740"]}, DOI={10.1614/WT-06-139.1}, abstractNote={Experiments were conducted at the Upper Coastal Plain Research Station near Rocky Mount and at the Peanut Belt Research Station near Lewiston-Woodville in 2002 and 2003. Peanut injury was minimal (< 5%) with all soil-applied programs. S-Metolachlor PRE alone or in mixture with sulfentrazone, diclosulam, or flumioxazin controlled annual grasses similarly (66 to 87%). The addition of imazapic plus 2,4-DB POST increased annual grass control (> 93%). Sulfentrazone or diclosulam in mixture with S-metolachlor were the best PRE options, with 94% and 92% control of yellow and purple nutsedge, respectively, with flumioxazin being least effective at 70%. Diclosulam and flumioxazin in mixture with S-metolachlor were the best PRE options, with 99% and 93%, respectively for common ragweed control, whereas sulfentrazone was the least effective at 65%. S-Metolachlor in mixture with sulfentrazone, diclosulam, or flumioxazin PRE were similar (87 to 90%) for common lambsquarters control. S-Metolachlor in mixture with sulfentrazone, diclosulam, or flumioxazin provided similar levels of entireleaf, ivyleaf, pitted, and tall morningglory control (87, 86, and 87%, respectively) and better than S-metolachlor alone at 64%. Flumioxazin in mixture with S-metolachlor was the best PRE option for control of Palmer amaranth at 96%, whereas diclosulam with S-metolachlor was the best PRE option for control of eclipta at 100%. The prepackaged mixture of acifluorfen and bentazon plus 2,4-DB POST and imazapic plus 2,4-DB POST were similar for all morningglory species (> 96%) and Palmer amaranth control (93 and 97%, respectively). Peanut treated with S-metolachlor plus diclosulam PRE numerically yielded the highest at 3,210 kg/ha, but were statistically equivalent to S-metolachlor plus flumioxazin PRE at 3,040 kg/ha. Peanut treated with imazapic plus 2,4-DB POST yielded the most at 3,400 kg/ha, while peanut treated with a prepackaged mixture of acifluorfen and bentazon plus 2,4-DB POST yielded less (3,070 kg/ha). Nomenclature: 2,4-DB, acifluorfen, bentazon, diclosulam, flumioxazin, imazapic, S-metolachlor, sulfentrazone, common lambsquarters, Chenopodium album L. CHEAL, common ragweed, Ambrosia artemisiifolia L. AMBEL, eclipta, Eclipta prostrata L. ECLAL, entireleaf morningglory, Ipomoea hederacea var. integriuscula Gray IPOHG, ivyleaf morningglory, Ipomoea hederacea (L.) Jacq. IPOHE, Palmer amaranth, Amaranthus palmeri S. Wats. AMAPA, pitted morningglory, Ipomoea lacunosa L. IPOLA, purple nutsedge, Cyperus rotundus L. CYPRO, tall morningglory, Ipomoea purpurea (L.) Roth PHBPU, yellow nutsedge, Cyperus esculentus L. CYPES, peanut, Arachis hypogaea L., ‘NCV-11’, ‘VA-98R’}, number={3}, journal={WEED TECHNOLOGY}, author={Clewis, Scott B. and Everman, Wesley J. and Jordan, David L. and Wilcut, John W.}, year={2007}, pages={629–635} } @article{lassiter_burke_thomas_pline-srnic_jordan_wilcut_wilkerson_2007, title={Yield and physiological response of peanut to glyphosate drift}, volume={21}, ISSN={["0890-037X"]}, DOI={10.1614/WT-07-045.1}, abstractNote={Five experiments were conducted during 2001 and 2002 in North Carolina to evaluate peanut injury and pod yield when glyphosate was applied to 10 to 15 cm diameter peanut plants at rates ranging from 9 to 1,120 g ai/ha. Shikimic acid accumulation was determined in three of the five experiments. Visual foliar injury (necrosis and chlorosis) was noted 7 d after treatment (DAT) when glyphosate was applied at 18 g/ha or higher. Glyphosate at 280 g/ha or higher significantly injured the peanut plant and reduced pod yield. Shikimic acid accumulation was negatively correlated with visual injury and pod yield. The presence of shikimic acid can be detected using a leaf tissue assay, which is an effective diagnostic tool for determining exposure of peanut to glyphosate 7 DAT.}, number={4}, journal={WEED TECHNOLOGY}, author={Lassiter, Bridget R. and Burke, Ian C. and Thomas, Walter E. and Pline-Srnic, Wendy A. and Jordan, David L. and Wilcut, John W. and Wilkerson, Gall G.}, year={2007}, pages={954–960} } @article{partridge_sutton_jordan_2006, title={Effect of environmental factors and pesticides on mycoparasitism of Sclerotinia minor by Coniothyrium minitans}, volume={90}, ISSN={["1943-7692"]}, DOI={10.1094/PD-90-1407}, abstractNote={ The effects of soil temperature and moisture, and nine pesticides commonly used in peanut production, on the mycoparasitic activity of Coniothyrium minitans on sclerotia of Sclerotinia minor were evaluated. In vitro mycelial growth and conidia germination of C. minitans were sensitive to azoxystrobin, chlorothalonil, fluazinam, pyraclostrobin, tebuconazole, and diclosulam. C. minitans survived and infected sclerotia of S. minor in the presence of azoxystrobin, chlorothalonil, diclosulam, fluazinam, flumioxazin, S-metolachlor, pendimethalin, pyraclostrobin, and tebuconazole. Mycoparasitic activity was reduced by all pesticides except S-metolachlor compared with the nontreated control. Optimum conditions for infection of sclerotia were temperatures from 14 to 22°C and soil moisture from -0.33 to -1 kPa × 102. Mycoparasitic activity of C. minitans remained high (98% sclerotia infected) at temperatures ranging from 14 to 22°C, but decreased at temperatures above 28°C. Viability of sclerotia was inversely related to the proportion infected by C. minitans (r = -0.9963, P = 0.001). Mycoparasitic activity also declined when soil moisture was greater than -1 kPa × 102 or less than -0.10 kPa × 102. These results indicate that C. minitans should not be applied when temperatures exceed 28°C, during extremes in soil moisture, or when there is a high risk of contact with pesticides before it becomes established in the soil. }, number={11}, journal={PLANT DISEASE}, author={Partridge, D. E. and Sutton, T. B. and Jordan, D. L.}, year={2006}, month={Nov}, pages={1407–1412} } @article{gardner_york_jordan_monks_2006, title={Glufosinate antagonizes postemergence graminicides applied to annual grasses and johnsongrass}, volume={10}, ISBN={1524-3303}, number={4}, journal={Journal of Cotton Science (Online)}, author={Gardner, A. P. and York, A. C. and Jordan, D. L. and Monks, D. W.}, year={2006}, pages={319} } @article{partridge_sutton_jordan_curtis_2006, title={Management of Sclerotinia blight of peanut with the biological control agent Coniothyrium minitans}, volume={90}, DOI={10.1094/PD-90-0957}, abstractNote={ Sclerotinia blight, caused by Sclerotinia minor, is an important disease of peanut in North Carolina. The effectiveness of Coniothyrium minitans, a mycoparasite of sclerotia of Sclerotinia spp., was studied in a 5-year field experiment and in eight short-term experiments in northeastern North Carolina. The 5-year experiment was initiated in November 1999 to evaluate the effectiveness of repeated soil applications of C. minitans (commercial formulation, Contans WG) at 2 and 4 kg ha-1 in reducing Sclerotinia blight. In addition, individual commercial peanut fields were selected in 2001 and 2002 to evaluate a single application of C. minitans at 4 kg ha-1. No differences were found between the 2 and 4 kg ha-1 rates of C. minitans in reducing Sclerotinia blight. In 2002, there was less disease in plots receiving applications of C. minitans for either 1 or 3 years compared with the nontreated control; whereas, in 2003, C. minitans applications for 1, 2, or 3 years reduced disease and the number of sclerotia isolated from soil. A single application of C. minitans reduced sclerotia in only two of the eight short-term experiments. The integration of consecutive years of soil applications of C. minitans at 2 kg ha-1 with moderately resistant cultivars and fungicide applications may aid in the management of Sclerotinia blight in peanut. }, number={7}, journal={Plant Disease}, author={Partridge, D. E. and Sutton, T. B. and Jordan, D. L. and Curtis, V. L.}, year={2006}, pages={957–963} } @article{gardner_york_jordan_monks_2006, title={Management of annual grasses and Amaranthus spp. in glufosinate-resistant cotton}, volume={10}, ISBN={1524-3303}, number={4}, journal={Journal of Cotton Science (Online)}, author={Gardner, A. P. and York, A. C. and Jordan, D. L. and Monks, D. W.}, year={2006}, pages={328} } @article{grabow_huffman_evans_jordan_nuti_2006, title={Water distribution from a subsurface drip irrigation system and dripline spacing effect on cotton yield and water use efficiency in a coastal plain soil}, volume={49}, DOI={10.13031/2013.22303}, abstractNote={A subsurface drip irrigation (SDI) system was installed in 2001 in the Coastal Plain of North Carolina. Initially, four zones were installed, each with 0.91 m dripline spacing. In 2002, a fifth zone with 1.82 m dripline spacing was added. This system irrigated a cotton (Gossypium hirsutum L.) and peanut (Arachis hypogea L.) rotation on a Norfolk sandy loam soil. Seed cotton yield data was collected from 2001 to 2004. In addition to SDI, overhead sprinkler irrigation was applied to cotton plots from 2001 to 2003. This study was concurrent with another study that evaluated the effect of irrigation system type, cotton growth regulator (mepiquat chloride), herbicide (glyphosate) treatment, and planting date on lint yield and quality. Although the soil is classified as a sandy loam, water moved laterally to the midpoint of the 1.82 m spaced dripline; this was likely due to the pan layer found at about 0.3 m just below the dripline depth of 0.23 m. There was no difference in lateral water movement between the two dripline spacings. Seed cotton yield and irrigation water use efficiency was not statistically different between irrigation system type or dripline spacing over all years in the study. Seed cotton yield averaged 3.44 Mg ha-1 for the 0.91 m dripline spacing and 3.22 Mg ha-1 for the 1.82 m spacing for the three-year period 2002-2004 compared to an unirrigated average of 2.58 Mg ha-1 for the same period. Average irrigation water use efficiency was greater for the 0.91 m dripline spacing but not statistically different from the 1.82 m spacing. For 2001-2003, when sprinkler-irrigated plots existed, seed cotton yield averaged 3.55 Mg ha-1 for the 0.91 m dripline spacing, 3.35 Mg ha-1 for the sprinkler-irrigated plots, and 2.56 Mg ha-1 for the unirrigated plots. Drought conditions existed in 2002, when 258 mm of rain occurred between planting and final irrigation. The other growing seasons received relatively high amounts of rainfall: 524, 555, and 643 mm in 2001, 2003, and 2004, respectively.}, number={6}, journal={Transactions of the ASABE}, author={Grabow, G. L. and Huffman, R. L. and Evans, R. O. and Jordan, D. L. and Nuti, R. C.}, year={2006}, pages={1823–1835} } @article{parker_york_jordan_2006, title={Weed control in glyphosate-resistant corn as affected by preemergence herbicide and timing of postemergence herbicide application}, volume={20}, ISSN={["0890-037X"]}, DOI={10.1614/WT-04-288R.1}, abstractNote={Field studies were conducted at three locations during both 2002 and 2003 to evaluate weed control and response of glyphosate-resistant (GR) corn to glyphosate or nicosulfuron plus atrazine applied POST at three application timings with and without alachlor plus atrazine applied PRE. The POST herbicides were applied timely (5- to 9-cm weeds) or applications were delayed 1 or 2 wk. All treatments, except the weedy check, were followed by glyphosate postemergence-directed (PDIR) 4 wk after the timely POST application. Common lambsquarters, common ragweed, Palmer amaranth, prickly sida, and smooth pigweed were controlled at least 94% regardless of PRE or POST treatments. Large crabgrass and fall panicum were controlled at least 96% by glyphosate regardless of PRE herbicide or POST application timing. In contrast, control by nicosulfuron plus atrazine POST in the absence of PRE herbicide decreased as application was delayed. Sicklepod was controlled at least 94% when POST herbicides were applied timely, but control by both POST herbicide treatments decreased with delayed application regardless of PRE herbicide. Tall morningglory was controlled 93% or greater by POST herbicides applied timely. Control by both POST herbicide treatments decreased as application was delayed, with glyphosate being affected more by timing than nicosulfuron plus atrazine. Corn grain yield was similar with glyphosate and nicosulfuron plus atrazine. Yield was unaffected by POST application timing when PRE herbicides were included. Without PRE herbicide, grain yield decreased as POST herbicide application was delayed.}, number={3}, journal={WEED TECHNOLOGY}, author={Parker, Robert G. and York, Alan C. and Jordan, David L.}, year={2006}, pages={564–570} } @article{parker_york_jordan_2005, title={Comparison of glyphosate products in glyphosate-resistant cotton (Gossypium hirsutum) and corn (Zea mays)}, volume={19}, ISSN={["1550-2740"]}, DOI={10.1614/WT-040271R2.1}, abstractNote={Wide-spread planting of glyphosate-resistant (GR) crops in the United States and glyphosate patent expiration has led to a proliferation of glyphosate products. Growers have questioned their advisors on efficacy and crop tolerance of the many products available. Field experiments were conducted to evaluate eight glyphosate products in 2002 and ten in 2003, representing isopropylamine, diammonium, and potassium salts, applied POST and postemergence-directed (PDIR) at 630 and 1,680 g ae/ha for GR corn and GR cotton tolerance and weed control. There were no differences among products for control of six annual grass and 10 annual broadleaf weed species. No injury to corn from any glyphosate product at 630 or 1,680 g/ha or to cotton from 630 g/ha was noted at any of seven locations. ClearOut 41 Plus™, an isopropylamine salt of glyphosate, and Roundup WEATHERMAX™, a potassium salt of glyphosate, applied POST at 1,680 g/ha injured cotton 27 to 30% and 10 to 17%, respectively, at 3 of 7 locations. No cotton injury was noted with Glyfos®, Glyfos® X-TRA, Glyphomax™, Gly Star™ Original, Roundup Original™, Roundup UltraMAX®, Touchdown®, or Touchdown Total™. No differences were noted among glyphosate products or between rates for corn or cotton yield or cotton fiber properties. Nomenclature: Glyphosate; corn, Zea mays L. ‘DK687’, ‘DKC 69-71’; cotton, Gossypium hirsutum L. ‘DP 458 B/RR’, ‘ST 4892BR’. Additional index words: ClearOut 41 Plus™, crop tolerance, diammonium salt of glyphosate, Glyfos®, Glyfos® X-TRA, Glyphomax™, Gly Star™ Original, isopropylamine salt of glyphosate, potassium salt of glyphosate, Roundup Original™, Roundup UltraMAX®, Roundup WEATHERMAX™, Touchdown®, Touchdown Total™, weed control. Abbreviations: EPSPS, 5-enolpyruvylshikimate-3-phosphate synthase; GR, glyphosate-resistant; PDIR, postemergence-directed; PEP, phosphoenolpyruvate; WAP, wk after postemergence application; WAP1, wk after first postemergence application; WAP2, wk after second postemergence application; WAPD, wk after postemergence-directed application.}, number={4}, journal={WEED TECHNOLOGY}, author={Parker, RG and York, AC and Jordan, DL}, year={2005}, pages={796–802} } @article{jordan_barnes_bogle_marshall_corbett_crozier_mclawhorn_fisher_2005, title={Influence of cultural practices and crop rotation on kenaf yield in North Carolina}, ISBN={1543-7833}, DOI={10.1094/cm-2005-0913-01-rs}, abstractNote={Kenaf is a relatively new crop to North Carolina and its impact on cropping systems has not been clearly determined. The impacts of crop rotation on kenaf, as well as the impacts of kenaf on rotation crops were examined. Crops preceding kenaf included corn, soybean, cotton, and peanut while crops following kenaf or corn included corn, soybean, cotton, peanut, and tobacco. Experiments were also conducted to define interactions among kenaf planting dates, row width/plant population systems, and cultivars. In one of two years, kenaf yield was lower when kenaf followed peanut or soybean compared to following cotton. Peanut and soybean yield were similar when following either corn and kenaf. However, corn and cotton yield was lower in one of two years when following corn compared to kenaf. Tobacco yield was similar when planted following either corn or kenaf. The interaction of planting date, row width/plant population, and cultivar was not significant for kenaf yield. No yield differences were observed between kenaf cultivars Everglade 41 and Tainung 2. Kenaf yield was higher when planted May 15 rather than June 15 and when kenaf was planted in rows spaced 8 inches apart (total plant population of 261,000 plants per acre) compared to rows spaced 36 inches apart (total plant population of 174,000 plants per acre).}, journal={Crop Management}, author={Jordan, D. L. and Barnes, J. S. and Bogle, C. R. and Marshall, T. M. and Corbett, T. and Crozier, C. R. and McLawhorn, B. and Fisher, L.}, year={2005}, pages={1} } @article{lancaster_jordan_york_burke_corbin_sheldon_wilcut_monks_2005, title={Influence of selected fungicides on efficacy of clethodim and sethoxydim}, volume={19}, ISSN={["1550-2740"]}, DOI={10.1614/WT-04-172R}, abstractNote={Field experiments were conducted to compare large crabgrass control by clethodim or sethoxydim applied alone and with selected fungicides registered for use in peanut. Fluazinam, propiconazole plus trifloxystrobin, or tebuconazole did not affect efficacy of clethodim or sethoxydim. Azoxystrobin, boscalid, chlorothalonil, and pyraclostrobin reduced efficacy of clethodim and sethoxydim in some experiments. Increasing the herbicide rate increased large crabgrass control regardless of the addition of chlorothalonil. In laboratory experiments,14C absorption was less when14C-clethodim or14C-sethoxydim was applied with chlorothalonil. Pyraclostrobin and tebuconazole did not affect absorption of14C-clethodim or14C-sethoxydim.}, number={2}, journal={WEED TECHNOLOGY}, author={Lancaster, SH and Jordan, DL and York, AC and Burke, IC and Corbin, FT and Sheldon, YS and Wilcut, JW and Monks, DW}, year={2005}, pages={397–403} } @article{lancaster_jordan_york_wilcut_monks_brandenburg_2005, title={Interactions of clethodim and sethoxydim with selected agrichemicals applied to peanut}, volume={19}, ISSN={["1550-2740"]}, DOI={10.1614/WT-04-232R}, abstractNote={Experiments were conducted in North Carolina during 2002 and 2003 to evaluate broadleaf signalgrass and large crabgrass control by clethodim and sethoxydim applied in two-, three-, or four-way mixtures with fungicides, insecticides, and foliar fertilizer–plant growth regulator treatments. Broadleaf signalgrass and large crabgrass control by clethodim and sethoxydim was not reduced by the insecticides esfenvalerate, indoxacarb, or lambda-cyhalothrin. The fungicides azoxystrobin, chlorothalonil, pyraclostrobin, and tebuconazole reduced large crabgrass control by clethodim or sethoxydim in one or more of three experiments for each herbicide. Disodium octaborate and the plant growth regulator prohexadione calcium plus urea ammonium nitrate (UAN) mixed with clethodim and fungicides improved large crabgrass control in some experiments. In contrast, prohexadione calcium plus UAN and disodium octaborate did not affect broadleaf signalgrass or large crabgrass control by sethoxydim.}, number={2}, journal={WEED TECHNOLOGY}, author={Lancaster, SH and Jordan, DL and York, AC and Wilcut, JW and Monks, DW and Brandenburg, RL}, year={2005}, pages={456–461} } @article{lancaster_jordan_york_wilcut_brandenburg_monks_2005, title={Interactions of late-season morningglory (Ipomoea spp.) management practices in peanut (Arachis hypogaea)}, volume={19}, ISSN={["1550-2740"]}, DOI={10.1614/WT-04-229R.1}, abstractNote={Experiments were conducted in North Carolina during 2002 and 2003 to evaluate entireleaf morningglory control by 2,4-DB applied alone or with seven fungicides. In a separate group of experiments, tall morningglory control by 2,4-DB was evaluated when applied in four-way mixtures with the following: the fungicides azoxystrobin, chlorothalonil, pyraclostrobin, or tebuconazole; the insecticide lambda-cyhalothrin; and the foliar fertilizer disodium octaborate or the plant growth regulator (PGR) prohexadione calcium plus urea ammonium nitrate. Pyraclostrobin, but not azoxystrobin, boscalid, chlorothalonil, fluazinam, propiconazole plus trifloxystrobin, or tebuconazole, reduced entireleaf morningglory control by 2,4-DB. Mixtures of fungicides, insecticides, and foliar fertilizer/ PGR did not affect tall morningglory control by 2,4-DB. Placing artificial morningglory in the peanut canopy when fungicides were applied did not intercept enough fungicide to increase peanut defoliation by early leaf spot and web blotch or reduce pod yield compared with fungicide applied without artificial morningglory. Nomenclature: 2,4-DB; azoxystrobin; boscalid; chlorothalonil; fluazinam; lambda-cyhalothrin; prohexadione calcium; propiconazole; pyraclostrobin; tebuconazole; trifloxystrobin; entireleaf morningglory, Ipomoea hederacaea var integriuscula Gray #3 IPOHG; tall morningglory, Ipomoea purpurea (L.) Roth # PHBPU; early leaf spot, Cercospora arachidicola S. Hori; web blotch, Phoma arachidicola (Marsas et al.); peanut, Arachis hypogaea L. ‘NC-V 11’, ‘VA 98R’. Additional index words: Fungicide deposition, pesticide interactions, weed interference. Abbreviations: PGR, plant growth regulator; UAN, urea ammonium nitrate.}, number={4}, journal={WEED TECHNOLOGY}, author={Lancaster, SH and Jordan, DL and York, AC and Wilcut, JW and Brandenburg, RL and Monks, DW}, year={2005}, pages={803–808} } @article{hurt_brandenburg_jordan_kennedy_bailey_2005, title={Management of spotted wilt vectored by Frankliniella fusca (Thysanoptera : Thripidae) in Virginia market-type peanut}, volume={98}, ISSN={["1938-291X"]}, DOI={10.1603/0022-0493-98.5.1435}, abstractNote={Abstract Field tests were conducted during 2001 and 2002 in northeastern North Carolina to evaluate the impact of cultural practices and in-furrow insecticides on the incidence of Tomato spotted wilt virus (genus Tospovirus, family Bunyaviridae, TSWV), which is transmitted to peanut, Arachis hypogaea L., primarily by tobacco thrips, Frankliniella fusca Hinds (Thysanoptera: Thripidae). Treatments included in row plant populations of 7, 13, and 17 plants per meter; the virginia market-type ‘NC V-11’ and ‘Perry’; planting dates of early and late May; and phorate and aldicarb insecticide applied in-furrow. The incidence of plants expressing visual symptoms of spotted wilt was recorded from mid-June through mid-September. Treatment factors that reduced the incidence of symptoms of plants expressing spotted wilt symptoms included establishing higher plant densities, delaying planting from early May until late May, and applying the in-furrow insecticide phorate. Peanut cultivar did not have a consistent, significant effect on the incidence of symptomatic plants in this experiment.}, number={5}, journal={JOURNAL OF ECONOMIC ENTOMOLOGY}, author={Hurt, CA and Brandenburg, RL and Jordan, DL and Kennedy, GG and Bailey, JE}, year={2005}, month={Oct}, pages={1435–1440} } @article{lanier_jordan_spears_wells_johnson_2005, title={Peanut response to inoculation and nitrogen fertilizer}, volume={97}, number={1}, journal={Agronomy Journal}, author={Lanier, J. E. and Jordan, D. L. and Spears, J. F. and Wells, R. and Johnson, P. D.}, year={2005}, pages={79–84} } @article{lancaster_jordan_spears_york_wilcut_monks_batts_brandenburg_2005, title={Sicklepod (Senna obtusifolia) control and seed production after 2,4-DB applied alone and with fungicides or insecticides}, volume={19}, ISSN={["1550-2740"]}, DOI={10.1614/WT-04-227R}, abstractNote={Experiments were conducted during 1999, 2002, and 2003 to evaluate sicklepod control by 2,4-DB applied alone or in mixture with selected fungicides and insecticides registered for use in peanut. The fungicides boscalid, chlorothalonil, fluazinam, propiconazole plus trifloxystrobin, pyraclostrobin, or tebuconazole and the insecticides acephate, carbaryl, esfenvalerate, fenpropathrin, lambda-cyhalothrin, methomyl, or indoxacarb applied in mixtures with 2,4-DB did not reduce sicklepod control by 2,4-DB compared with 2,4-DB alone. The fungicide azoxystrobin reduced control in some but not all experiments. Sicklepod control was highest when 2,4-DB was applied before flowering regardless of fungicide treatment. Seed production and germination were reduced when 2,4-DB was applied 81 to 85 d after emergence when sicklepod was flowering. Applying 2,4-DB before flowering and at pod set and pod fill did not affect seed production.}, number={2}, journal={WEED TECHNOLOGY}, author={Lancaster, SH and Jordan, DL and Spears, JE and York, AC and Wilcut, JW and Monks, DW and Batts, RB and Brandenburg, RL}, year={2005}, pages={451–455} } @article{burke_price_wilcut_jordan_culpepper_tredaway-ducar_2004, title={Annual grass control in peanut (Arachis hypogaea) with clethodim and imazapic}, volume={18}, ISSN={["1550-2740"]}, DOI={10.1614/WT-03-026R}, abstractNote={Field experiments were conducted to evaluate possible interactions of clethodim with imazapic applied as mixtures or sequentially for control of broadleaf signalgrass, fall panicum, goosegrass, and large crabgrass. Imazapic at 70 g ai/ha alone controlled grass weeds inconsistently, whereas clethodim at 140 g ai/ha alone controlled the same weeds at least 99%. Imazapic did not affect broadleaf signalgrass control by clethodim. Reduced control of fall panicum, goosegrass, and large crabgrass was observed when clethodim and imazapic were applied in mixture. Antagonism of clethodim occurred when clethodim was applied 1 d before or up to 3 d after application of imazapic (fall panicum and large crabgrass). Antagonism of goosegrass control was noted when imazapic was applied 3 d before or up to 7 d after application of clethodim. In other experiments, large crabgrass and Texas panicum control by clethodim (70 and 140 g/ha) applied alone or with imazapic (70 g/ ha) or bentazon (1.1 kg ai/ha) plus 2,4-DB (0.28 kg ai/ha) either with or without ammonium sulfate (2.8 kg/ha) was evaluated. Texas panicum control by clethodim was reduced by imazapic regardless of the ammonium sulfate rate. However, large crabgrass control by imazapic was not affected in these experiments. Control of both grasses by clethodim was reduced substantially by bentazon plus 2,4-DB, although in some instances ammonium sulfate improved control when in mixture. Ammonium sulfate improved control by clethodim in some instances irrespective of the broadleaf–sedge herbicide treatments. Nomenclature: Bentazon; clethodim; 2,4-DB; imazapic; broadleaf signalgrass, Brachiaria platyphylla (Griseb) Nash #3 BRAPP; fall panicum, Panicum dichotomiflorum L. # PANDI; goosegrass, Eleusine indica L. Gaertn. # ELEIN; large crabgrass, Digitaria sanguinalis L. Scop. # DIGSA; Texas panicum, Panicum texanum Buckl. # PANTE. Additional index words: Ammonium sulfate, antagonism, herbicide compatibility, herbicide interaction, sequential application.}, number={1}, journal={WEED TECHNOLOGY}, author={Burke, IC and Price, AJ and Wilcut, JW and Jordan, DL and Culpepper, AS and Tredaway-Ducar, J}, year={2004}, pages={88–92} } @article{lanier_jordan_barnes_matthews_grabow_griffin_bailey_johnson_spears_wells_2004, title={Disease management in overhead sprinkler and subsurface drip irrigation systems for peanut}, volume={96}, ISSN={["1435-0645"]}, DOI={10.2134/agronj2004.1058}, abstractNote={Experiments were conducted during 2001 and 2002 at one location in North Carolina to compare development of early leaf spot (Cercospora arachidicola Hori), pod yield, and market grade characteristics when peanut (Arachis hypogea L.) was grown under overhead sprinkler irrigation (OSI) and subsurface drip irrigation (SDI) and fungicides were not applied or applied biweekly or based on weather advisories. Incidence of early leaf spot was lower when peanut was grown under SDI compared with OSI when fungicides were not applied. Fewer fungicide applications were needed when applications were based on weather advisories rather than when applied biweekly. There was no difference in early leaf spot control or leaf defoliation resulting from disease when fungicides were applied regardless of irrigation system or fungicide application approach. Pod yield was higher in 2001 under SDI compared with OSI when fungicides were not applied; yield was similar in 2002. Disease severity was much higher in 2001 than in 2002 and most likely explains differences in pod yield between years. No difference in yield was noted when fungicides were applied, regardless of irrigation system. The percentage of extra large kernels (%ELK) was lower in 1 of 2 yr under SDI compared with OSI. There were no differences in percentages of fancy pods (%FP), sound splits (%SS), and other kernels (%OK) among irrigation systems and fungicide programs. In a separate experiment where fungicides were applied biweekly, pod yield, %FP, and %ELK were similar under SDI and OSI but greater than nonirrigated peanut. The %OK was lower when peanut was irrigated.}, number={4}, journal={AGRONOMY JOURNAL}, author={Lanier, JE and Jordan, DL and Barnes, JS and Matthews, J and Grabow, GL and Griffin, WJ and Bailey, JE and Johnson, PD and Spears, JF and Wells, R}, year={2004}, pages={1058–1065} } @article{lanier_jordan_spears_wells_johnson_barnes_hurt_brandenburg_bailey_2004, title={Peanut response to planting pattern, row spacing, and irrigation}, volume={96}, ISSN={["1435-0645"]}, DOI={10.2134/agronj2004.1066}, abstractNote={Experiments were conducted from 1999 through 2002 in North Carolina to compare interactions of planting pattern, plant population, and irrigation on peanut (Arachis hypogaea L.) pod yield and market grade characteristics. In additional experiments, pod yield and severity of tomato spotted wilt tospovirus associated with the cultivars NC‐V 11, NC 12C, VA 98R, and Perry were compared in single row (rows spaced 91 cm apart) and standard twin row (two rows spaced 18 cm apart on 91‐cm centers) planting patterns when peanut was dug and vines inverted on two digging dates spaced 10 to 16 d apart. In a third set of experiments, pod yield, market grade characteristics, and severity of tomato spotted wilt tospovirus were compared when the cultivars NC‐V 11 and Perry were planted in single row, standard twin row, and narrow twin row (two rows spaced 18 cm apart on 46‐cm centers) planting patterns. Peanut pod yield was higher in standard twin row planting patterns than when grown in single row planting patterns in some but not all experiments. Planting peanut in the narrow twin row pattern did not increase peanut pod yield over the standard twin row planting pattern. Less tomato spotted wilt was observed in standard or narrow twin row planting patterns compared with single row planting patterns. Planting peanut in single rows spaced 46 cm apart did not improve yield over peanut planted in single rows spaced 91 cm apart or the standard twin row planting pattern, regardless of irrigation treatment.}, number={4}, journal={AGRONOMY JOURNAL}, author={Lanier, JE and Jordan, DL and Spears, JF and Wells, R and Johnson, PD and Barnes, JS and Hurt, CA and Brandenburg, RL and Bailey, JE}, year={2004}, pages={1066–1072} } @article{crooks_york_jordan_2004, title={Tolerance of six soft red winter wheat cultivars to AE F130060 00 plus AE F115008 00}, volume={18}, ISSN={["1550-2740"]}, DOI={10.1614/WT-03-031R}, abstractNote={Tolerance of six soft red winter wheat cultivars to AE F130060 00 plus AE F115008 00 applied at 12.5 plus 2.5 g ai/ha and 25 plus 5 g ai/ha, respectively, at the two- to three-tiller stage was examined under weed-free conditions at four locations over 2 yr. Visible injury averaged 5 and 15% 3 wk after treatment (WAT) in years 1 and 2, respectively. Injury was 2% or less 10 WAT. No differences among cultivars were noted for visible injury, and AE F130060 00 plus AE F115008 00 did not reduce grain yield in year 1. In year 2, averaged over herbicide rates, grain yields of the cultivars ‘Coker 9663’, ‘Pioneer 2580’, ‘Coker 9704’, ‘Pioneer 2684’, ‘FFR 555’, and ‘Jackson’ were reduced 3, 5, 6, 8, 10, and 16%, respectively. The yield reduction for Jackson was different from those for the other cultivars. Yield reduction was attributed to reduced numbers of kernels per spike.}, number={2}, journal={WEED TECHNOLOGY}, author={Crooks, HL and York, AC and Jordan, DL}, year={2004}, pages={252–257} } @article{crooks_york_jordan_2004, title={Wheat (Triticuin aestivum) tolerance and Italian ryegrass (Lolium multiflorum) control with AE f130060 00 plus AE f115008 00 applied in nitrogen}, volume={18}, ISSN={["1550-2740"]}, DOI={10.1614/WT-03-029R}, abstractNote={Soft red winter wheat tolerance to and Italian ryegrass control by a mixture of AE F130060 00 plus AE F115008 00 plus safener applied in water or urea ammonium nitrate (UAN) were evaluated in separate experiments. In the tolerance experiment, wheat responded similarly to AE F130060 00 plus AE F115008 00 at 12.5 plus 2.5 and 25 plus 5 g ai/ha, respectively, applied in water. The herbicides plus nonionic surfactant (NIS) applied in water injured weed-free, five- to seven-tiller wheat 3% or less and did not affect yield. Greater injury occurred with application in UAN, and yield was reduced 11% as result of fewer kernels per spike. NIS added to the herbicides in UAN increased weed-free wheat injury but had no effect on yield. AE F130060 00 plus AE F115008 00 controlled both diclofop-susceptible and -resistant Italian ryegrass. Greater control was obtained with application in UAN as compared with application in water, and NIS increased control. Yield of Italian ryegrass–infested wheat treated with herbicides plus NIS in UAN was similar to or greater than yield when herbicides plus NIS were applied in water. Nomenclature: AEF 115008 00 (proposed name iodosulfuron-methyl-sodium), 4-iodo-2-[[[[(4-methoxy-6-methyl-1,3,5-triazin-2-yl)amino]carbonyl]amino]sulfonyl]benzoic acid methyl ester; AE F130060 00 (proposed name mesosulfuron-methyl), methyl 2-[[[[(4,6-dimethoxy-2-pyrimidinyl)amino]carbonyl]amino]sulfonyl]-4-[[(methylsulfonyl)amino]methyl] benzoate; Italian ryegrass, Lolium multiflorum Lam. Marshall #3 LOLMU; wheat, Triticum aestivum L. ‘Coker 9704’. Additional index words: Herbicide carriers, surfactant rates, yield components, LOLMU. Abbreviations: GS, Feekes growth stage; NIS, nonionic surfactant; UAN, urea ammonium nitrate; WAT, weeks after treatment.}, number={1}, journal={WEED TECHNOLOGY}, author={Crooks, HL and York, AC and Jordan, DL}, year={2004}, pages={93–99} } @article{crooks_york_jordan_2004, title={Wheat tolerance to AE f130060 00 plus AE f115008 00 as affected by time of application and rate of the safener AE F107892}, volume={18}, ISSN={["1550-2740"]}, DOI={10.1614/WT-03-122R1}, abstractNote={Soft red winter wheat response to the herbicides AE F130060 00 plus AE F115008 00 applied alone or with the safener AE F107892 at the three-leaf, two-tiller, and six-tiller growth stages was determined in a field experiment in North Carolina. AE F130060 00 at 25 g ai/ha plus AE F115008 00 at 5 g ai/ha, twice the anticipated use rate, applied with safener injured wheat 9% but did not affect grain yield, grain test weight, number of spikes, number of kernels per spike, or kernel weight. Results were similar with safener at herbicide–safener ratios of 1:1 and 1:3 regardless of the wheat growth stage at application. Without the safener, AE F130060 00 plus AE F115008 00 applied at the three-leaf, two-tiller, and six-tiller growth stages injured wheat an average of 27% and reduced grain yields 5, 5, and 11%, respectively. Yield losses were attributed to reduced numbers of kernels per spike. AE F130060 00 at 12.5 g/ha plus AE F115008 00 at 2.5 g/ha plus AE F107892 at 15 g ai/ha did not affect grain yield or yield components.}, number={3}, journal={WEED TECHNOLOGY}, author={Crooks, HL and York, AC and Jordan, DL}, year={2004}, pages={841–845} } @article{corkern_reynolds_griffin_jordan_miller_p.r._2003, title={Cotton sensitivity to pyrithiobac applied under two irrigation regimes}, volume={7}, number={4}, journal={Journal of Cotton Science}, author={Corkern, C.B. and Reynolds, D.B. and Griffin, J.L. and Jordan, D.L. and Miller, D.K. and P.R., Vidrine}, year={2003}, pages={236–241} } @article{jordan_wilkerson_krueger_2003, title={Evaluation of scouting methods in peanut (Arachis hypogaea) using theoretical net returns from HADSS (TM)}, volume={17}, ISSN={["1550-2740"]}, DOI={10.1614/0890-037X(2003)017[0358:EOSMIP]2.0.CO;2}, abstractNote={A perceived limitation to incorporating herbicide application decision support system (HADSS™) into routine peanut weed management decisions is efficient scouting of fields. A total of 52 peanut fields were scouted from 1997 through 2001 in North Carolina to determine the weed density in a 9.3-m2 section for each 0.4-ha grid of the field. These weed populations and their spatial distributions were used to compare theoretical net return (TNR) over herbicide investment for various scouting methods and weed management approaches. HADSS was used to determine the expected net return for each treatment in each 0.4-ha section of every field under differing assumptions of weed size, soil moisture conditions, and pricing structures. The treatment with the highest net return averaged across all 0.4-ha grids was considered to be the optimal whole-field treatment. For all 52 fields, TNR for the best whole-field treatment and for site-specific weed management (applying the most economical recommendation on each 0.4-ha grid) averaged $414 and $435/ha, respectively. Estimated return from the commercial postemergence herbicide program of aciflurofen plus bentazon plus 2,4-DB followed by clethodim (where grass was present) averaged $316/ha across all 52 fields. For fields of 5 ha or more (17 fields) in which 12 or more samples were taken, TNR was $500, $510, and $516/ha for three-sample (one pass through the middle of the field with samples taken on both ends and the center of the field), six-sample (two passes through the field with three stops per pass), and full-sample (one stop for each 0.4 ha) approaches, respectively. Nomenclature: Peanut, Arachis hypogaea L. Additional index words: Economic thresholds, prescription weed management, weed interference, weed scouting, weed thresholds. Abbreviations: HADSS, herbicide application decision support system; TNR, theoretical net return over herbicide investment.}, number={2}, journal={WEED TECHNOLOGY}, author={Jordan, DL and Wilkerson, GG and Krueger, DW}, year={2003}, pages={358–365} } @article{jordan_barnes_bogle_brandenburg_bailey_johnson_culpepper_2003, title={Peanut response to cultivar selection, digging date, and tillage intensity}, volume={95}, ISSN={["1435-0645"]}, DOI={10.2134/agronj2003.0380}, abstractNote={reduced tillage systems often do not exceed those of conventional tillage. Determining the cause of inconsisPeanut (Arachis hypogaea L.) in the United States is generally tent yield response to reduced tillage would be benefigrown in conventionally tilled systems. However, interest in reduced tillage peanut production has increased. Five experiments were concial in determining when reduced tillage systems could ducted in North Carolina to determine if cultivar selection and digging be successfully implemented in peanut production. date affected peanut yield and economic value when peanut was Cultivar selection can have a dramatic effect on crop seeded into conventionally tilled seedbeds compared with strip tillage response to production and pest management practices. into small-grain cover crop or stubble from the crop planted the preCulpepper et al. (1997) reported that peanut cultivars vious summer. In separate experiments, peanut yield and economic responded differently to the plant growth regulator provalue in these tillage systems were compared with peanut strip-tilled hexadione calcium (calcium salt of 3,5-dioxo-4-propiointo beds prepared the previous fall (stale seedbeds). Cultivar selection nylcyclohexanecarboxylic acid). Cultivars also respond and digging date did not affect pod yield or gross value when compardifferently to digging date (Jordan et al., 1998). Disease ing tillage systems. Pod yield in conventional and stale seedbed sysmanagement approaches can be affected by cultivar setems was similar in all five experiments where these systems were compared, and yields in these tillage systems exceeded those of strip lection (Bailey, 2002). Virginia market-type cultivars vary tillage into crop stubble in three of five experiments. Pod yield was considerably in pod size, maturity, and several other agrosimilar among all three tillage systems in the other two experiments. nomic factors (Swann, 2002). Although not well estabIn experiments where only conventional tillage and strip tillage syslished in the literature, pod loss can be severe if peanut tems were compared, pod yield was similar between the two tillage is dug under poor soil conditions (Beam et al., 2002). systems in four experiments, higher in conventional tillage compared It is suspected that pod loss may be greater in reduced with strip tillage in one experiment, and higher for strip tillage comtillage systems than conventional tillage systems bepared with conventional tillage in one experiment. In 16 of 17 comcause the plants may be more difficult to dig. Peanut parisons, pod yield of peanut planted in conventional tillage systems cultivars with larger pods may be more susceptible to equaled or exceeded that of peanut planted into stubble from the digging losses compared with smaller-seeded cultivars previous crop. because they have a greater surface area, which may cause increased exposure to detachment during the digging process. Practitioners indicate that pod loss from P in the United States is typically grown in smaller-seeded runner market types is less than that for conventionally tilled systems (Sholar et al., 1995). large-seeded virginia market types during the digging Peanut response to reduced tillage has been inconsiscomponent of the harvest process. However, these comtent. Research suggests that yields in reduced tillage sysparisons have not been documented in the literature. tems can be lower than (Brandenburg et al., 1998; Cox Determining if pod yield differs among tillage systems and Sholar, 1995; Grichar, 1998; Jordan et al., 2001; for cultivars with different pod sizes may help explain Sholar et al., 1993; Wright and Porter, 1995) or similar inconsistent peanut response to reduced tillage systems. to (Baldwin and Hook, 1998; Dowler et al., 1999; HartStale seedbed crop production has been successful zog et al., 1998; Williams et al., 1998) yields in convenfor a variety of row crops, including soybean [Glycine tional tillage systems. Higher yields in reduced tillage max (L.) Merr.] and cotton (Gossypium hirsutum L.) systems have been associated with lower incidence of (Shaw, 1996). Seedbeds are prepared the previous fall tomato spotted wilt virus (TSWV) (Baldwin and Hook, or during the spring several weeks or months before 1998; Johnson et al., 2001; Wright et al., 2000). In most seeding directly into previously established stale seedexperiments where this disease is not a factor, yields in bed without significant soil disturbance. This approach to peanut production may be a viable alternative to both D.L. Jordan, P.D. Johnson, and A.S. Culpepper, Dep. of Crop Sci., conventional tillage systems and strip tillage directly Box 7620, North Carolina State Univ., Raleigh, NC 27695-7620; J.S. into stubble from the previous crop. Barnes, Peanut Belt Res. Stn., North Carolina Dep. of Agric. and The objectives of this research were to determine if Consumer Serv., Box 220, Lewiston-Woodville, NC 27849; C.R. Bogle, Dep. of Soil Sci., North Carolina State Univ., Upper Coastal Plain peanut response to tillage was associated with cultivar Res. Stn., Box 7619, Raleigh, NC 27695 and North Carolina Dep. of selection and digging date and if peanut yield in stale Agric. and Consumer Serv., Rt. 2 Box 400, Rocky Mount, NC 27801; seedbeds differs from yield in conventional tillage or R.L. Brandenburg, Dep. of Entomol., Box 7613, North Carolina State strip tillage into crop stubble. Univ., Raleigh, NC 27695-7613; and J.E. Bailey, Dep. of Plant Pathol., Box 7616, North Carolina State Univ., Raleigh, NC 27695-7616. ReAbbreviations: CBR, Cylindrocladium black rot; %ELK, percentage ceived 11 Apr. 2002. *Corresponding author (david_jordan@ncsu.edu). of extra large kernels; %TSMK, percentage of total sound mature kernels; TSWV, tomato spotted wilt virus. Published in Agron. J. 95:380–385 (2003).}, number={2}, journal={AGRONOMY JOURNAL}, author={Jordan, DL and Barnes, JS and Bogle, CR and Brandenburg, RL and Bailey, JE and Johnson, PD and Culpepper, AS}, year={2003}, pages={380–385} } @article{crooks_york_jordan_2003, title={Wheat (Triticum aestivum) tolerance and Italian Ryegrass (Lolium multiflorum) control by AE F130060 00 plus AE F115008 00 mixed with other herbicides}, volume={17}, DOI={10.1614/wt-03-030r}, abstractNote={Soft red winter wheat tolerance and Italian ryegrass control with AE F130060 00 plus AE F115008 00 at 12.5 plus 2.5 g ai/ha applied alone and mixed with dicamba, 2,4-D, or thifensulfuron plus tribenuron were examined in separate field experiments. AE F130060 00 plus AE F115008 00 applied alone in December injured wheat 12% or less, whereas mixtures with thifensulfuron plus tribenuron injured wheat 15% or less. AE F130060 00 plus AE F115008 00 applied alone in February or mixed with dicamba, 2,4-D, or thifensulfuron plus tribenuron injured wheat 3% or less. No treatment affected yield of weed-free wheat. AE F130060 00 plus AE F115008 00 applied in December controlled Italian ryegrass 86 to 99% in May and increased wheat yield 142 to 254%. At two of four locations, Italian ryegrass control was greater with the December application of AE F130060 00 plus AE F115008 as compared with the February application. Dicamba or 2,4-D mixed with AE F130060 00 plus AE F115008 00 reduced Italian ryegrass control in May approximately 10% in half the trials but did not affect wheat yield compared with AE F130060 00 plus AE F115008 00 applied alone. Thifensulfuron plus tribenuron mixed with AE F130060 00 plus AE F115008 00 did not affect Italian ryegrass control or wheat yield. Under greenhouse conditions, the rate of AE F130060 00 plus AE F115008 00 needed for 80% Italian ryegrass visible control and 80% shoot fresh weight reduction was increased 60 to 68% in mixtures with 2,4-D. Dicamba increased the rate needed for 80% visible control and shoot fresh weight reduction 132 to 139%. Nomenclature: AE F115008 00 (proposed name iodosulfuron-methyl-sodium), 4-iodo-2-[[[[(4-methoxy-6-methyl-1,3,5-triazin-2-yl)amino]carbonyl]amino]sulfonyl]benzoic acid methyl ester; AE F130060 00 (proposed name mesosulfuron-methyl), methyl 2-[[[[(4,6-dimethoxy-2-pyrimidinyl)amino]carbonyl]amino]sulfonyl]-4-[[(methylsulfonyl)amino]methyl]benzoate; Italian ryegrass, Lolium multiflorum Lam. #3 LOLMU; wheat, Triticum aestivum L. ‘Coker 9704’. Additional index words: 2,4-D, dicamba, herbicide interactions, herbicide mixtures, LOLMU, thifensulfuron, tribenuron. Abbreviations: I80, rate needed for 80% inhibition; NIS, nonionic surfactant; WAT, weeks after treatment.}, number={4}, journal={Weed Technology}, author={Crooks, H. L. and York, A. C. and Jordan, D. L.}, year={2003}, pages={881–889} } @article{beam_jordan_york_isleib_bailey_mckemie_spears_johnson_2002, title={Influence of prohexadione calcium on pod yield and pod loss of peanut}, volume={94}, DOI={10.2134/agronj2002.9550}, abstractNote={Excessive vegetative growth of peanut (Arachis hypogaea L.) can make digging and inverting operations less efficient. Reducing vine growth by applying a suitable plant growth regulator would be an efficient way to manage peanut vines. Pod yield, market grade factors, and gross economic value of peanut treated with prohexadione calcium (calcium salt of 3,5-dioxo-4 propionylcyclohexanecarboxylic acid) were evaluated at 19 sites in North Carolina during 1999 and 2000. Experiments were also conducted at two locations each during 1999 and 2000 to determine the effect of prohexadione Ca, digging date, and lifting (shaking peanut vines after digging to remove soil before combining) on combined yield, market grade factors, gross economic value, seed germination, and pod loss of the virginia market-type cultivar NC 12C. Prohexadione Ca at 140 g a.i. ha -1 , applied at 50% row closure and repeated 2 wk later, increased row visibility at harvest, pod yield by 310 kg ha -1 , and gross economic value of quota peanut by $223 ha -1 when pooled over 19 sites. Prohexadione Ca increased combined yield by 220 kg ha -1 and decreased percent pod loss by 4% regardless of digging date and lifting treatment compared with nontreated peanut. Prohexadione Ca did not affect maximum yield (sum of pods remaining in soil and on the soil surface and pods that were combined) or germination of peanut seed. These data suggest that increased combined yield noted following application of prohexadione Ca can be partially attributed to decreased pod loss.}, number={2}, journal={Agronomy Journal}, author={Beam, J. B. and Jordan, D. L. and York, A. C. and Isleib, T. G. and Bailey, J. E. and McKemie, T. E. and Spears, J. F. and Johnson, P. D.}, year={2002}, pages={331–336} } @article{jordan_bailey_barnes_bogle_bullen_brown_edmisten_dunphy_johnson_2002, title={Yield and economic return of ten peanut-based cropping systems}, volume={94}, ISSN={["0002-1962"]}, DOI={10.2134/agronj2002.1289}, abstractNote={Research was conducted in North Carolina at two locations from 1997 through 2000 to determine net returns of 10 cropping systems during a 4‐yr cropping cycle that included peanut (Arachis hypogaea L.), cotton (Gossypium hirsutum L.), soybean [Glycine max (L.) Merr.], and corn (Zea mays L.). Cylindrocladium black rot [caused by Cylindrocladium parasiticum] (CBR) increased when soybean was included in the rotation sequence or when peanut was grown continuously. The CBR‐resistant cultivar NC 12C increased yield compared with the susceptible cultivar NC 7 when this disease was present. Cotton was a better rotation crop than corn at one of two locations with respect to peanut yield and gross economic value in the final year of the study. Net returns were substantially lower when peanut was marketed for export in the current federal program rather than at the quota price. However, the profitability ranking among cropping systems changed little regardless of marketing system. Crop yield and net return were influenced by crop selection, weather conditions, and commodity prices during the 4 yr.}, number={6}, journal={AGRONOMY JOURNAL}, author={Jordan, DL and Bailey, JE and Barnes, JS and Bogle, CR and Bullen, SG and Brown, AB and Edmisten, KL and Dunphy, EJ and Johnson, PD}, year={2002}, pages={1289–1294} } @article{jordan_warren_miller_smith_reynolds_crawford_griffin_2001, title={Italian ryegrass control with preplant herbicides}, volume={5}, ISBN={1524-3303}, number={4}, journal={Journal of Cotton Science (Online)}, author={Jordan, D. L. and Warren, L. S., Jr. and Miller, D. K. and Smith, M. C. and Reynolds, D. B. and Crawford, S. H. and Griffin, J. L.}, year={2001}, pages={268} } @article{jordan_beam_johnson_spears_2001, title={Peanut response to prohexadione calcium in three seeding rate-row pattern planting systems}, volume={93}, ISSN={["0002-1962"]}, DOI={10.2134/agronj2001.931232x}, abstractNote={Peanut (Arachis hypogaea L.) in the USA is generally grown in single rows spaced 91 to 102 cm apart. Research suggests that pod yield can be increased by growing peanut in twin rows (18–23 cm spacing) on beds spaced 91 to 102 cm apart. Prohexadione Ca (Ca salt of 3,5‐dioxo‐4‐propionylcyclohexanecarboxylic acid) increases row visibility and in some instances increases pod yield and improves market grade factors. Research was conducted to determine response of peanut grown in three seeding rate–row pattern planting systems (single rows at a seeding rate of 120 kg ha−1 or twin rows spaced 18 cm apart on beds spaced 91 cm apart at seeding rates of 145 and 190 kg ha−1) to prohexadione Ca applied at 50% row closure. Row visibility increased and main stem height was shorter at the end of the season when prohexadione Ca was applied in most environments and for most seeding rate–row pattern combinations when compared with nontreated peanut. Pod yield and gross economic value increased 160 kg ha−1 and $96 ha−1, respectively, when prohexadione Ca was applied irrespective of the seeding rate–row pattern combination or environment. Prohexadione Ca also increased the percentage of extra large kernels (% ELK) but did not affect percentages of sound mature kernels (SMK), other kernels (OK), sound splits (SS), or total sound mature kernels (TSMK). Seeding rate–row pattern combination affected pod yield, market grade, and gross economic value although a consistent trend was not apparent.}, number={1}, journal={AGRONOMY JOURNAL}, author={Jordan, DL and Beam, JB and Johnson, PD and Spears, JF}, year={2001}, pages={232–236} } @article{jordan_barnes_bogle_naderman_roberson_johnson_2001, title={Peanut response to tillage and fertilization}, volume={93}, ISSN={["1435-0645"]}, DOI={10.2134/agronj2001.9351125x}, abstractNote={Peanut (Arachis hypogaea L.) in the USA is generally seeded after several primary tillage operations that may include disking, chisel plowing, moldboard plowing, and bedding (conventional tillage systems). Concerns over erosion and production costs have increased interest in reduced tillage systems. Production in reduced tillage systems minimizes ability to incorporate fertilizers below the pegging zone, and residue on soil surface could impact movement of calcium sulfate (CaSO4) into the soil, reducing Ca availability to pegs. Research was conducted from 1997 through 1999 to compare peanut yield and gross economic value of virginia market type peanut planted in conventional and strip tillage systems. Preplant fertilizer did not affect response to tillage. Response did not differ among conventional tillage systems consisting of disk, disk and chisel, or disk and moldboard plow or among reduced tillage systems. Pod yield of peanut grown in the most effective conventional tillage system exceeded yield when peanut was strip‐tilled into stubble of the previous crop, strip‐tilled into a wheat (Triticum aestivum L.) cover crop, or strip‐tilled into beds prepared the previous fall without a cover crop. Tillage system and CaSO4 rate affected pod yield and gross value independently. Gross value increased when CaSO4 was applied regardless of tillage system. These data suggest that preplant fertilizer at relatively low, remedial rates does not affect peanut response to tillage systems. These data also suggest that tillage system does not have a major impact on peanut response to CaSO4. Collectively, these data indicate that the highest peanut yields occur in conventional tillage systems.}, number={5}, journal={AGRONOMY JOURNAL}, author={Jordan, DL and Barnes, JS and Bogle, CR and Naderman, GC and Roberson, GT and Johnson, PD}, year={2001}, pages={1125–1130} } @article{bollich_jordan_walker_burns_2000, title={Rice (Oryza sativa) response to the microencapsulated formulation of clomazone}, volume={14}, ISSN={["0890-037X"]}, DOI={10.1614/0890-037X(2000)014[0089:ROSRTT]2.0.CO;2}, abstractNote={Abstract: Experiments were conducted in 1996 and 1997 in water-seeded and drill-seeded production systems to determine rice response to clomazone applied at rates ranging from 0.28 to 2.2 kg ai/ha on silt loam and silty clay soils. Clomazone-induced bleaching of rice seedlings was 15% or less when clomazone was applied at 0.28 or 0.56 kg/ha. Increasing the rate of clomazone increased bleaching in most experiments. Clomazone at 0.84 kg/ha or higher delayed seed head emergence in five of eight experiments. Clomazone at lower rates did not delay seed head emergence. Although clomazone at 0.28 and 0.56 kg/ha did not reduce grain yield, clomazone at 0.84 and 1.1 kg/ha reduced grain yield in one experiment while clomazone at 1.7 and 2.2 kg/ha reduced yield in two experiments. The influence of soil type and seeding method on rice's tolerance to the microencapsulated formulation of clomazone could not be demonstrated in these experiments. Clomazone was more injurious in drill-seeded production than in water-seeded production. Nomenclature: Clomazone, 2-[(2-chlorophenyl)methyl]-4,4-dimethyl-3-isoxazolidinone; rice, Oryza sativa L. ‘Cypress’. Additional index words: Crop injury. Abbreviations: PRE, preemergence.}, number={1}, journal={WEED TECHNOLOGY}, author={Bollich, PK and Jordan, DL and Walker, DM and Burns, AB}, year={2000}, pages={89–93} } @article{culpepper_york_jordan_corbin_sheldon_1999, title={Basis for antagonism in mixtures of bromoxynil plus quizalofop-P applied to yellow foxtail (Setaria glauca)}, volume={13}, ISSN={["1550-2740"]}, DOI={10.1017/s0890037x00046121}, abstractNote={Antagonism of quizalofop-P efficacy on annual grasses by bromoxynil has been noted in both the field and greenhouse. Laboratory experiments were conducted on yellow foxtail (Setaria glauca) to determine the effect of mixing bromoxynil with the ethyl ester of quizalofop-P on absorption, translocation, and metabolism of14C-quizalofop-P Applying bromoxynil in mixture with quizalofop-P reduced14C-label absorption from 63 to 51%, 73 to 52%, 77 to 68%, and 90 to 80% at 4, 8, 24, and 96 h after treatment, respectively. Translocation of14C-label from the treated leaf into the shoot above or shoot below was unaffected by bromoxynil. However, translocation into the roots was reduced from 0.9 to 0.4% and 1.0 to 0.5% at 4 and 8 h after treatment, respectively, but differences were not noted at 0.5, 1, 24, and 96 h after treatment. Bromoxynil increased deesterification of quizalofop-P-ethyl into quizalofop-P acid from 45 to 60% in the shoot above the treated leaf. However, bromoxynil did not affect metabolism of quizalofop-P in the treated leaf or shoot below the treated leaf. These results suggest that antagonism of quizalofop-P activity by bromoxynil is primarily due to decreased absorption of quizalofop-P, whereas effects on translocation and metabolism were minor.}, number={3}, journal={WEED TECHNOLOGY}, author={Culpepper, AS and York, AC and Jordan, DL and Corbin, FT and Sheldon, YS}, year={1999}, pages={515–519} } @article{culpepper_jordan_york_corbin_sheldon_1999, title={Influence of adjuvants and bromoxynil on absorption of clethodim}, volume={13}, ISSN={["1550-2740"]}, DOI={10.1017/s0890037x00046169}, abstractNote={The effect of nonionic surfactant, crop oil concentrate, organosilicone surfactant, methylated seed oil, and a blend of organosilicone surfactant and methylated seed oil on absorption of14C-clethodim was evaluated in barnyardgrass (Echinochloa crus-galli). Absorption of14C-label was greatest during the first 40 min after application when14C-clethodim was applied with methylated seed oil or a blend of methylated seed oil and organosilicone surfactant. These adjuvants increased the rate of absorption more than crop oil concentrate, organosilicone surfactant, or nonionic surfactant. Crop oil concentrate was more effective than organosilicone or nonionic surfactant in increasing absorption, with nonionic surfactant being more effective than organosilicone surfactant. These results generally agreed with the order of increasing efficacy of clethodim on barnyardgrass as affected by adjuvants in field experiments. Another study was conducted to determine the effect of bromoxynil on absorption and translocation of14C-clethodim in yellow foxtail (Setaria glauca). Bromoxynil reduced absorption of14C–clethodim 4, 8, and 24 h after application and also reduced the amount of14C-label translocated from the treated leaf. These data suggest that antagonism of clethodim control of yellow foxtail by bromoxynil observed in previous research can be attributed partially to decreased absorption and translocation of clethodim.}, number={3}, journal={WEED TECHNOLOGY}, author={Culpepper, AS and Jordan, DL and York, AC and Corbin, FT and Sheldon, Y}, year={1999}, pages={536–541} } @article{jordan_bollich_braverman_sanders_1999, title={Influence of tillage and Triticum aestivum cover crop on herbicide efficacy in Oryza sativa}, volume={47}, number={3}, journal={Weed Science}, author={Jordan, D. L. and Bollich, P. K. and Braverman, M. P. and Sanders, D. E.}, year={1999}, pages={332–337} } @article{grymes_griffin_leonard_jordan_boethel_1999, title={Influence of weeds on insecticide deposition and soybean looper (Pseudoplusia includens) management}, volume={47}, number={3}, journal={Weed Science}, author={Grymes, C. F. and Griffin, J. L. and Leonard, B. R. and Jordan, D. L. and Boethel, D. J.}, year={1999}, pages={321–326} } @article{bailey_wilcut_jordan_swann_langston_1999, title={Response of peanut (Arachis hypogaea) and selected weeds to diclosulam}, volume={13}, ISSN={["1550-2740"]}, DOI={10.1017/s0890037x00042214}, abstractNote={Field studies were conducted at five locations in North Carolina and Virginia during 1996 and 1997 to evaluate weed control, peanut (Arachis hypogaea) response, and peanut yield following diclosulam applied preplant incorporated (PPI) and in systems with commercial herbicide standards. All plots received a PPI treatment of ethalfluralin at 840 g ai/ha. Ethalfluralin plus diclosulam controlled entireleaf morningglory (Ipomoea hederaceavar.integriuscula), ivyleaf morningglory (I. hederacea), pitted morningglory (I. lacunosa), common lambsquarters (Chenopodium album), eclipta (Eclipta prostrata), and prickly sida (Sida spinosa) as well as and frequently better than ethalfluralin PPI followed by (fb) acifluorfen plus bentazon postemergence (POST), paraquat plus bentazon early postemergence (EPOST) fb imazapic POST, or imazapic POST. Systems with ethalfluralin plus diclosulam PPI at 26 g ai/ha fb acifluorfen plus bentazon POST controlled a broader spectrum of weeds and yielded greater than systems of ethalfluralin PPI fb imazapic POST or ethalfluralin PPI fb acifluorfen plus bentazon POST. Peanut exhibited excellent tolerance to diclosulam PPI at 17, 26, or 35 g/ha.}, number={4}, journal={WEED TECHNOLOGY}, author={Bailey, WA and Wilcut, JW and Jordan, DL and Swann, CW and Langston, VB}, year={1999}, pages={771–776} } @article{grymes_griffin_boethel_leonard_jordan_russin_1999, title={Soybean response to weed interference and defoliation}, volume={47}, number={1}, journal={Weed Science}, author={Grymes, C. F. and Griffin, J. L. and Boethel, D. J. and Leonard, B. R. and Jordan, D. L. and Russin, J. S.}, year={1999}, pages={90–94} } @article{bailey_wilcut_jordan_swann_langston_1999, title={Weed management in peanut (Arachis hypogaea) with diclosulam preemergence}, volume={13}, ISSN={["0890-037X"]}, DOI={10.1017/s0890037x00046017}, abstractNote={Field studies were conducted at five locations in North Carolina and Virginia in 1996 and 1997 to evaluate weed control and peanut (Arachis hypogaea) response to diclosulam that was applied preemergence (PRE) and in systems with commercial standards. All plots received a preplant incorporated (PPI) treatment of ethalfluralin at 840 g ai/ha. Diclosulam controlled common lambsquarters (Chenopodium albumL.), eclipta (Eclipta prostrataL.), entireleaf morningglory (Ipomoea hederaceavar.integriusculaGray), ivyleaf morningglory [Ipomoea hederacea(L.) Jacq.], pitted morningglory (Ipomoea lacunosaL.), and prickly sida (Sida spinosaL.) as well as and frequently better than the commercial standards of acifluorfen plus bentazon applied postemergence (POST), paraquat plus bentazon early POST followed by (fb) imazapic POST, or imazapic POST. Systems with ethalfluralin PPI plus diclosulam PRE at 26 g ai/ha fb acifluorfen plus bentazon POST controlled a broader spectrum of weeds and yielded greater than systems of ethalfluralin PPI fb imazapic POST or ethalfluralin PPI fb acifluorfen plus bentazon POST. Peanut exhibited excellent tolerance to diclosulam PRE at 17, 26, or 35 g/ha.}, number={3}, journal={WEED TECHNOLOGY}, author={Bailey, WA and Wilcut, JW and Jordan, DL and Swann, CW and Langston, VB}, year={1999}, pages={450–456} } @article{jordan_miller_crawford_1998, title={Barnyardgrass (Echinochloa crus-galli) control in dry-seeded rice (Oryza sativa) with soil-applied and postemergence herbicide programs}, volume={12}, ISSN={["0890-037X"]}, DOI={10.1017/s0890037x00042597}, abstractNote={A study was conducted from 1994 through 1996 to evaluate barnyardgrass control, rice yield, and estimated economic returns with delayed preemergence (DPRE) applications of pendimethalin, quinclorac, thiobencarb, pendimethalin plus quinclorac, and pendimethalin plus thiobencarb applied alone or followed by postemergence (POST) applications of propanil or propanil plus molinate. Late-season barnyardgrass control with pendimethalin plus quinclorac was greater than with pendimethalin, quinclorac, thiobencarb, or pendimethalin plus thiobencarb. Control with pendimethalin, quinclorac, and pendimethalin plus thiobencarb exceeded that with thiobencarb. Propanil plus molinate controlled barnyardgrass more effectively than propanil. Quinclorac and pendimethalin plus quinclorac were the only DPRE herbicide treatments where yield and estimated economic returns were not improved by POST herbicides.}, number={1}, journal={WEED TECHNOLOGY}, author={Jordan, DL and Miller, DK and Crawford, SH}, year={1998}, pages={69–73} } @article{jordan_kendig_1998, title={Barnyardgrass (Echinochloa crus-galli) control with postemergence applications of propanil and clomazone in dry- seeded rice (Oryza sativa)}, volume={12}, DOI={10.1017/s0890037x00044274}, abstractNote={Field experiments were conducted to compare barnyardgrass control and rice grain yield following a single postemergence (POST) application of propanil plus clomazone with single or repeat POST applications of propanil alone or single POST applications of propanil plus pendimethalin, molinate, quinclorac, or thiobencarb. In four of 10 experiments, propanil plus clomazone controlled barnyardgrass better than single or repeat applications of propanil alone or single applications of propanil plus pendimethalin, molinate, quinclorac, or thiobencarb. The most consistent increase in rice yield over a single application of propanil occurred where clomazone was applied in mixture with propanil.}, number={3}, journal={Weed Technology}, author={Jordan, D. L. and Kendig, J. A.}, year={1998}, pages={537–541} } @article{bailey_wilcut_jordan_askew_hinton_langston_1998, title={Evaluation of Strongarm (DE 564, diclosulam) for weed control in southeastern peanuts}, volume={51}, number={1998}, journal={Proceedings, Southern Weed Science Society}, author={Bailey, W. A. and Wilcut, J. W. and Jordan, D. L. and Askew, S. D. and Hinton, J. D. and Langston, V. B.}, year={1998}, pages={59} } @article{jordan_johnson_1998, title={Influence of adjuvants on efficacy of 2,4-DB, CADRE, and Strongarm}, volume={51}, number={1998}, journal={Proceedings, Southern Weed Science Society}, author={Jordan, D. L. and Johnson, P. D.}, year={1998}, pages={60–61} } @article{jordan_coble_brandenburg_bailey_1998, title={Relationship of weed populations and herb in selected North Carolina peanut fields}, volume={51}, number={1998}, journal={Proceedings, Southern Weed Science Society}, author={Jordan, D. L. and Coble, H. D. and Brandenburg, R. L. and Bailey, J. E.}, year={1998}, pages={215–216} } @article{jordan_sanders_linscombe_williams_1998, title={Response of four rice (Oryza sativa) cultivars to triclopyr}, volume={12}, ISSN={["0890-037X"]}, DOI={10.1017/s0890037x00043773}, abstractNote={Experiments were conducted from 1994 through 1996 to determine the response of the rice cultivars ‘Bengal,’ ‘Cypress,’ ‘Jodon,’ and ‘Kaybonnet’ to triclopyr at 0.42 (standard rate) and 0.84 kg ai/ha applied postemergence at the four-leaf and panicle initiation stages of growth. Applications at the four-leaf stage were made in close association with fertilization and flood establishment, which often increases the potential for triclopyr to injure rice. Visible injury from triclopyr was slightly higher for the cultivar Jodon than for the cultivars Bengal, Cypress, or Kaybonnet. Injury was 3% or less when triclopyr at 0.42 kg/ha was applied at panicle initiation regardless of the cultivar. Triclopyr at 0.42 and 0.84 kg/ha applied at the four-leaf growth stage injured rice 7% and 22%, respectively. Triclopyr at 0.84 kg/ha applied at the four-leaf stage of growth delayed days from seedling emergence to seed head emergence and rice grain yield, irrespective of cultivar.}, number={2}, journal={WEED TECHNOLOGY}, author={Jordan, DL and Sanders, DE and Linscombe, SD and Williams, BJ}, year={1998}, pages={254–257} } @article{jordan_bollich_burns_walker_1998, title={Rice (Oryza sativa) response to clomazone}, volume={46}, number={3}, journal={Weed Science}, author={Jordan, D. L. and Bollich, P. K. and Burns, A. B. and Walker, D. M.}, year={1998}, pages={374–380} } @article{jordan_1997, title={Efficacy of reduced rates of quinclorac applied with propanil or propanil plus molinate in dry-seeded rice (Oryza sativa)}, volume={45}, number={6}, journal={Weed Science}, author={Jordan, D. L.}, year={1997}, pages={824–828} } @article{jordan_1997, title={Efficacy of reduced-rate herbicide combinations in dry-seeded rice (Oryza sativa) on alluvial clay soil}, volume={45}, number={1}, journal={Weed Science}, author={Jordan, D. L.}, year={1997}, pages={151–157} } @article{jordan_burns_1997, title={Influence of adjuvants on hemp Sesbania (Sesbania exaltata) control by chlorimuron}, volume={11}, ISSN={["1550-2740"]}, DOI={10.1017/s0890037x00041270}, abstractNote={Hemp sesbania control by chlorimuron applied with crop oil concentrate at 1.0% v/v, BCH 815 at 1.0% v/v, methylated seed oil at 1.0% v/v, a blend of methylated seed oil and organosilicone surfactant at 0.5% v/v, organosilicone-based surfactant at 0.125% v/v, and nonionic surfactant at 0.25% v/v was evaluated in field studies in 1994 and 1995. Control by chlorimuron at 4.5 g ae/ha was greater when applied with BCH 815, organosilicone-based surfactant, and nonionic surfactant than with crop oil concentrate, methylated seed oil, and a blend of methylated seed oil and organosilicone surfactant. When chlorimuron was applied at 4.5 g/ha with BCH 815 or nonionic surfactant, hemp sesbania control was similar to that by chlorimuron at 9 g/ha applied with methylated seed oil, the blend of methylated seed oil and organosilicone surfactant, or organosilicone-based surfactant.}, number={1}, journal={WEED TECHNOLOGY}, author={Jordan, DL and Burns, AB}, year={1997}, pages={19–23} } @article{jordan_york_griffin_clay_vidrine_reynolds_1997, title={Influence of application variables on efficacy of glyphosate}, volume={11}, ISSN={["1550-2740"]}, DOI={10.1017/s0890037x00043062}, abstractNote={Field experiments were conducted from 1993 to 1995 to compare weed control by the isopropylamine salt of glyphosate at 0.21, 0.42, 0.63, and 0.84 kg ae/ha applied at three stages of weed growth. Weed control by glyphosate applied at these rates alone or with ammonium sulfate at 2.8 kg/ha was also evaluated. In other experiments, potential interactions between glyphosate and acifluorfen, chlorimuron, and 2,4-DB were evaluated. Velvetleaf, prickly sida, sicklepod, pitted morningglory, entireleaf morningglory, palmleaf morningglory, and hemp sesbania were controlled more easily when weeds had one to three leaves compared with control when weeds had four or more leaves. Glyphosate controlled redroot pigweed, velvetleaf, prickly sida, sicklepod, and barnyardgrass more effectively than pitted morningglory, entireleaf morningglory, palmleaf morningglory, or hemp sesbania. Increasing the rate of glyphosate increased control, especially when glyphosate was applied to larger weeds. Greater variation in control was noted for pitted morningglory, palmleaf morningglory, prickly sida, and velvetleaf than for redroot pigweed, sicklepod, entireleaf morningglory, or hemp sesbania. Ammonium sulfate increased prickly sida and entireleaf morningglory control but did not influence sicklepod, hemp sesbania, or barnyardgrass control. Acifluorfen applied 3 d before glyphosate or in a mixture with glyphosate reduced barnyardgrass control compared with glyphosate applied alone. Chlorimuron did not reduce efficacy. Mixtures of glyphosate and 2,4-DB controlled sicklepod, entireleaf morningglory, and barnyardgrass similar to glyphosate alone.}, number={2}, journal={WEED TECHNOLOGY}, author={Jordan, DL and York, AC and Griffin, JL and Clay, PA and Vidrine, PR and Reynolds, DB}, year={1997}, pages={354–362} } @article{jordan_reynolds_crawford_1997, title={Rice (Oryza sativa) response to soil residues of selected herbicides}, volume={11}, ISSN={["0890-037X"]}, DOI={10.1017/s0890037x00043104}, abstractNote={The potential of alachlor, SAN 582H (Proposed name, dimethenamid), chlorimuron plus metribuzin, clomazone, imazaquin, imazethapyr, metolachlor, sulfentrazone, and trifluralin plus flumetsulam to injure rice the year following application to soybean was evaluated on silty clay and silt loam soils in Louisiana. These herbicides did not cause rice injury or yield reduction. Rice tolerance of the amine salt of 2,4-D or thifensulfuron plus tribenuron applied 0, 7, 14, and 28 d prior to planting was also evaluated on these soils. The amine salt of 2,4-D at 1.1 kg ai/ha injured rice 43 and 52% on silty clay and silt loam soils, respectively, in 1994 when applied the day of planting. In 1995, injury was 78 and 88% on these respective soils at this timing. When applied 7 d or more before planting, 2,4-D amine injured rice in one of four trials. Thifensulfuron plus tribenuron (17 + 9 g ai/ha) injured rice in one of four trials when applied the day of planting, but did not injure rice when applied 7 d before planting. No visual rice injury was observed when 2,4-D amine or thifensulfuron plus tribenuron was applied 14 or 28 d before planting. Rice grain yield was not affected by thifensulfuron plus tribenuron regardless of the interval between application and rice planting. In contrast, rice grain yield was reduced in all trials when 2,4-D amine was applied on the day of planting, and in one of four trials when applied 7 or 14 d before planting.}, number={2}, journal={WEED TECHNOLOGY}, author={Jordan, DL and Reynolds, DB and Crawford, SH}, year={1997}, pages={379–383} } @article{wilcut_jordan_vencill_richburg_1997, title={Weed management in cotton (Gossypium hirsutum) with soil-applied and post-directed herbicides}, volume={11}, ISSN={["0890-037X"]}, DOI={10.1017/s0890037x00042871}, abstractNote={Broadleaf weed and yellow nutsedge control with herbicide programs containing pendimethalin and combinations of fomesafen, fluometuron, and norflurazon applied alone or with POST-directed applications of MSMA or fluometuron plus MSMA was evaluated. Soil-applied herbicide combinations containing fomesafen controlled yellow nutsedge better than combinations of norflurazon and fluometuron but did not provide better entireleaf, ivyleaf, pitted, and tall morningglory or sicklepod control. Fluometuron plus MSMA controlled morningglories and sicklepod more effectively than MSMA. Seed cotton yield was greater in one of two years when fomesafen was applied and was associated with better yellow nutsedge control.}, number={2}, journal={WEED TECHNOLOGY}, author={Wilcut, JW and Jordan, DL and Vencill, WK and Richburg, JS}, year={1997}, pages={221–226} }