@article{huddell_needelman_law_ackroyd_bagavathiannan_bradley_davis_evans_everman_flessner_et al._2024, title={Early-season biomass and weather enable robust cereal rye cover crop biomass predictions}, volume={9}, ISSN={["2471-9625"]}, DOI={10.1002/ael2.20121}, abstractNote={AbstractFarmers need accurate estimates of winter cover crop biomass to make informed decisions on termination timing or to estimate potential release of nitrogen from cover crop residues to subsequent cash crops. Utilizing data from an extensive experiment across 11 states from 2016 to 2020, this study explores the most reliable predictors for determining cereal rye cover crop biomass at the time of termination. Our findings demonstrate a strong relationship between early‐season and late‐season cover crop biomass. Employing a random forest model, we predicted late‐season cereal rye biomass with a margin of error of approximately 1,000 kg ha−1 based on early‐season biomass, growing degree days, cereal rye planting and termination dates, photosynthetically active radiation, precipitation, and site coordinates as predictors. Our results suggest that similar modeling approaches could be combined with remotely sensed early‐season biomass estimations to improve the accuracy of predicting winter cover crop biomass at termination for decision support tools.}, number={1}, journal={AGRICULTURAL & ENVIRONMENTAL LETTERS}, author={Huddell, Alexandra and Needelman, Brian and Law, Eugene P. and Ackroyd, Victoria J. and Bagavathiannan, Muthukumar V. and Bradley, Kevin and Davis, Adam S. and Evans, Jeffery A. and Everman, Wesley Jay and Flessner, Michael and et al.}, year={2024}, month={Jun} } @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{huddell_thapa_marcillo_abendroth_ackroyd_armstrong_asmita_bagavathiannan_balkcom_basche_et al._2024, title={US cereal rye winter cover crop growth database}, volume={11}, ISSN={["2052-4463"]}, DOI={10.1038/s41597-024-02996-9}, abstractNote={Abstract}, number={1}, journal={SCIENTIFIC DATA}, author={Huddell, Alexandra M. and Thapa, Resham and Marcillo, Guillermo S. and Abendroth, Lori J. and Ackroyd, Victoria J. and Armstrong, Shalamar D. and Asmita, Gautam and Bagavathiannan, Muthukumar V. and Balkcom, Kipling S. and Basche, Andrea and et al.}, year={2024}, month={Feb} } @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={Abstract}, 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{ramanathan_gannon_locke_everman_2023, title={Characterizing atrazine, mesosulfuron-methyl, and topramezone bioavailability in North Carolina soils using greenhouse bioassays}, volume={6}, ISSN={2639-6696}, url={http://dx.doi.org/10.1002/agg2.20371}, DOI={10.1002/agg2.20371}, abstractNote={Abstract}, number={2}, journal={AGROSYSTEMS GEOSCIENCES & ENVIRONMENT}, publisher={Wiley}, author={Ramanathan, Shwetha S. and Gannon, Travis W. and Locke, Anna M. and Everman, Wesley J.}, year={2023}, month={Jun} } @article{jones_andres_owen_dunne_contreras_cahoon_jennings_leon_everman_2023, title={Confirmation of a five-way herbicide-resistant Amaranthus tuberculatus population in North Carolina}, volume={7}, ISSN={["1365-3180"]}, url={https://doi.org/10.1111/wre.12590}, DOI={10.1111/wre.12590}, abstractNote={Abstract}, journal={WEED RESEARCH}, author={Jones, Eric A. L. and Andres, Ryan J. and Owen, Micheal D. K. and Dunne, Jeffrey C. and Contreras, Diego J. and Cahoon, Charles W. and Jennings, Katherine M. and Leon, Ramon G. and Everman, Wesley J.}, year={2023}, month={Jul} } @article{jones_austin_dunne_leon_everman_2023, title={Discrimination between protoporphyrinogen oxidase-inhibiting herbicide-resistant and herbicide-susceptible redroot pigweed (Amaranthus retroflexus) with spectral reflectance}, volume={5}, ISSN={["1550-2759"]}, url={https://doi.org/10.1017/wsc.2023.25}, DOI={10.1017/wsc.2023.25}, abstractNote={Abstract}, journal={WEED SCIENCE}, author={Jones, Eric A. L. and Austin, Robert and Dunne, Jeffrey C. and Leon, Ramon G. and Everman, Wesley J.}, year={2023}, month={May} } @article{howell_haug_everman_leon_richardson_2023, title={Low carrier volume herbicide trials and UAAS support management efforts of giant salvinia (Salvinia molesta): a case study}, volume={5}, ISSN={["1939-747X"]}, url={https://doi.org/10.1017/inp.2023.16}, DOI={10.1017/inp.2023.16}, abstractNote={Abstract}, journal={INVASIVE PLANT SCIENCE AND MANAGEMENT}, author={Howell, Andrew W. and Haug, Erika J. and Everman, Wesley J. and Leon, Ramon G. and Richardson, Robert J.}, year={2023}, month={May} } @article{howell_leon_everman_mitasova_nelson_richardson_2023, title={Performance of unoccupied aerial application systems for aquatic weed management: Two novel case studies}, volume={5}, ISSN={["1550-2740"]}, url={https://doi.org/10.1017/wet.2023.32}, DOI={10.1017/wet.2023.32}, abstractNote={Abstract}, journal={WEED TECHNOLOGY}, author={Howell, Andrew W. and Leon, Ramon G. and Everman, Wesley J. and Mitasova, Helena and Nelson, Stacy A. C. and Richardson, Robert J.}, year={2023}, month={May} } @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={Abstract}, 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{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={Abstract}, 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{ramanathan_gannon_everman_locke_2022, title={Atrazine, mesosulfuron‐methyl, and topramezone persistence in North Carolina soils}, volume={114}, ISSN={0002-1962 1435-0645}, url={http://dx.doi.org/10.1002/agj2.21041}, DOI={10.1002/agj2.21041}, abstractNote={Abstract}, note={title = {Atrazine, mesosulfuron-methyl, and topramezone persistence in North Carolina soils}, journal = {Agronomy Journal}}, number={2}, journal={Agronomy Journal}, publisher={Wiley}, author={Ramanathan, Shwetha S. and Gannon, Travis W. and Everman, Wesley J. and Locke, Anna M.}, year={2022}, month={Mar}, pages={1068–1079} } @article{jones_leon_everman_2022, title={Biological effects on Palmer amaranth surviving glufosinate}, volume={5}, ISSN={["2639-6696"]}, url={https://doi.org/10.1002/agg2.20315}, DOI={10.1002/agg2.20315}, abstractNote={Abstract}, number={4}, journal={AGROSYSTEMS GEOSCIENCES & ENVIRONMENT}, author={Jones, Eric and Leon, Ramon G. and Everman, Wesley Jay}, year={2022} } @article{jones_leon_everman_2022, title={Control of pervasive row crop weeds with dicamba and glufosinate applied alone, mixed, or sequentially}, volume={10}, ISSN={["1550-2740"]}, url={https://doi.org/10.1017/wet.2022.80}, DOI={10.1017/wet.2022.80}, abstractNote={Abstract}, journal={WEED TECHNOLOGY}, author={Jones, Eric A. L. and Leon, Ramon G. and Everman, Wesley J.}, year={2022}, month={Oct} } @article{contreras_leon_post_everman_2022, title={Critical period of grass weed control in ALS-tolerant grain sorghum (Sorghum bicolor) is affected by planting date and environment}, volume={4}, ISSN={["2673-3218"]}, DOI={10.3389/fagro.2022.1014801}, abstractNote={Field experiments were conducted at two locations in North Carolina (Clayton and Rocky Mount) to determine the influence of row spacing and planting date on the critical period of weed control (CPWC) of grass weeds in ALS-tolerant grain. Grain sorghum was planted in May and June 2019, with either a 38 or 91 cm row spacing using an ALS-tolerant sorghum variety. Treatments consisted of “weedy” or “weed-free” plots up to 2, 3, 5, and 7 weeks after crop planting (WAP) and two control treatments of weedy and weed-free all season. Selection of grass weed species was achieved by controlling broadleaf weeds with a premix of bromoxynil plus pyrasulfutole at a rate of 264 g a.i. ha-1.Grass weeds were controlled using nicosulfuron at a rate of 69 g of a.i. ha-1. The CPWC was significantly different across locations. Row spacing and planting date factors did not influence the CPWC at Clayton. Planting date was a significant factor for the CPWC at Rocky Mount, however row spacing did not have any effect on the CPWC. Results for the CPWC are presented in terms growing degree days (GDD) from the date of crop sowing. The CPWC for grass weeds in grain sorghum at Clayton was from 368 to 849 GDD. The CPWC at Rocky Mount for May-planted grain sorghum was from 405 to 876 GDD, while the CPWC for June-planted grain sorghum ranged from 228 to 1042 GDD. These results demonstrate that cultural and environmental factors may influence the beginning, duration and end of the CPWC.}, journal={FRONTIERS IN AGRONOMY}, author={Contreras, Diego and Leon, Ramon G. and Post, Angela R. and Everman, Wesley J.}, year={2022}, month={Sep} } @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={Abstract}, 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{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={Abstract}, 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{joyner_cahoon_everman_collins_taylor_blythe_2022, title={HPPD-resistant cotton response to isoxaflutole applied preemergence and postemergence}, ISSN={["1550-2740"]}, DOI={10.1017/wet.2022.6}, abstractNote={Abstract}, journal={WEED TECHNOLOGY}, author={Joyner, Joshua D. and Cahoon, Charles W. and Everman, Wesley J. and Collins, Guy D. and Taylor, Zachary R. and Blythe, Andrew C.}, year={2022}, month={Feb} } @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={Abstract}, 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{spoth_haring_everman_reberg-horton_greene_flessner_2022, title={Narrow-windrow burning to control seeds of Italian ryegrass (Lolium perenne ssp. multiflorum) in wheat and Palmer amaranth (Amaranthus palmeri) in soybean}, volume={9}, ISSN={["1550-2740"]}, url={https://doi.org/10.1017/wet.2022.70}, DOI={10.1017/wet.2022.70}, abstractNote={Abstract}, journal={WEED TECHNOLOGY}, author={Spoth, Matthew P. and Haring, Steven C. and Everman, Wesley and Reberg-Horton, Chris and Greene, Wykle C. and Flessner, Michael L.}, year={2022}, month={Sep} } @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{jones_cahoon_leon_everman_2022, title={Surveying stakeholder's perception of glufosinate and use in North Carolina}, volume={5}, ISSN={["1550-2740"]}, url={https://doi.org/10.1017/wet.2022.31}, DOI={10.1017/wet.2022.31}, abstractNote={Abstract}, journal={WEED TECHNOLOGY}, author={Jones, Eric A. L. and Cahoon, Charles W. and Leon, Ramon G. and Everman, Wesley J.}, year={2022}, month={May} } @article{jones_austin_dunne_cahoon_jennings_leon_everman_2022, title={Utilization of image-based spectral reflectance to detect herbicide resistance in glufosinate-resistant and glufosinate-susceptible plants: a proof of concept}, volume={12}, ISSN={["1550-2759"]}, url={https://doi.org/10.1017/wsc.2022.68}, DOI={10.1017/wsc.2022.68}, abstractNote={Abstract}, journal={WEED SCIENCE}, author={Jones, Eric A. L. and Austin, Robert and Dunne, Jeffrey C. and Cahoon, Charles W. and Jennings, Katherine M. and Leon, Ramon G. and Everman, Wesley J.}, year={2022}, month={Dec} } @article{glaspie_jones_penner_pawlak_everman_2021, title={Effect of Clay, Soil Organic Matter, and Soil pH on Initial and Residual Weed Control with Flumioxazin}, volume={11}, ISSN={["2073-4395"]}, DOI={10.3390/agronomy11071326}, abstractNote={Greenhouse studies were conducted to evaluate the effects of soil organic matter content and soil pH on initial and residual weed control with flumioxazin by planting selected weed species in various lab-made and field soils. Initial control was determined by planting weed seeds into various lab-made and field soils treated with flumioxazin (71 g ha−1). Seeds of Echinochloa crus-galli (barnyard grass), Setaria faberi (giant foxtail), Amaranthus retroflexus (redroot pigweed), and Abutilon theophrasti (velvetleaf) were incorporated into the top 1.3 cm of each soil at a density of 100 seeds per pot, respectively. Emerged plants were counted and removed in both treated and non-treated pots two weeks after planting and each following week for six weeks. Flumioxazin control was evaluated by calculating percent emergence of weeds in treated soils compared to the emergence of weeds in non-treated soils. Clay content was not found to affect initial flumioxazin control of any tested weed species. Control of A. theophrasti, E. crus-galli, and S. faberi was reduced as soil organic matter content increased. The control of A. retroflexus was not affected by organic matter. Soil pH below 6 reduced flumioxazin control of A. theophrasti, and S. faberi but did not affect the control of A. retroflexus and E. crus-galli. Flumioxazin residual control was determined by planting selected weed species in various lab-made and field soils 0, 2, 4, 6, and 8 weeks after treatment. Eight weeks after treatment, flumioxazin gave 0% control of A. theophrasti and S. faberi in all soils tested. Control of A. retroflexus and Chenopodium album (common lambsquarters) was 100% for the duration of the experiment, except when soil organic matter content was greater than 3% or the soil pH 7. Eight weeks after treatment, 0% control was only observed for common A. retroflexus and C. album in organic soil (soil organic matter > 80%) or when soil pH was above 7. Control of A. theophrasti and S. faberi decreased as soil organic matter content and soil pH increased. Similar results were observed when comparing lab-made soils to field soils; however, differences in control were observed between lab-made organic matter soils and field organic matter soils. Results indicate that flumioxazin can provide control ranging from 75–100% for two to six weeks on common weed species.}, number={7}, journal={AGRONOMY-BASEL}, author={Glaspie, Calvin F. and Jones, Eric A. L. and Penner, Donald and Pawlak, John A. and Everman, Wesley J.}, year={2021}, month={Jul} } @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{flessner_burke_dille_everman_vangessel_tidemann_manuchehri_soltani_sikkema_2021, title={Potential wheat yield loss due to weeds in the United States and Canada}, volume={35}, ISSN={["1550-2740"]}, DOI={10.1017/wet.2021.78}, abstractNote={Abstract}, number={6}, journal={WEED TECHNOLOGY}, author={Flessner, Michael L. and Burke, Ian C. and Dille, J. Anita and Everman, Wesley J. and VanGessel, Mark J. and Tidemann, Breanne and Manuchehri, Misha R. and Soltani, Nader and Sikkema, Peter H.}, year={2021}, month={Dec}, pages={916–923} } @article{sanders_jones_austin_roberson_richardson_everman_2021, title={Remote Sensing for Palmer Amaranth (Amaranthus palmeri S. Wats.) Detection in Soybean (Glycine max (L.) Merr.)}, volume={11}, ISSN={["2073-4395"]}, DOI={10.3390/agronomy11101909}, abstractNote={Field studies were conducted in 2016 and 2017 to determine if multispectral imagery collected from an unmanned aerial vehicle (UAV) equipped with a five-band sensor could successfully identify Palmer amaranth (Amaranthus palmeri) infestations of various densities growing among soybeans (Glycine max [L.] Merr.). The multispectral sensor captures imagery from five wavebands: 475 (blue), 560 (green), 668 (red), 840 (near infrared [NIR]), and 717 nm (red-edge). Image analysis was performed to examine the spectral properties of discrete Palmer amaranth and soybean plants at various weed densities using these wavebands. Additionally, imagery was subjected to supervised classification to evaluate the usefulness of classification as a tool to differentiate the two species in a field setting. Date was a significant factor influencing the spectral reflectance values of the Palmer amaranth densities. The effects of altitude on reflectance were less clear and were dependent on band and density being evaluated. The near infrared (NIR) waveband offered the best resolution in separating Palmer amaranth densities. Spectral separability in the other wavebands was less defined, although low weed densities were consistently able to be discriminated from high densities. Palmer amaranth and soybean were found to be spectrally distinct regardless of imaging date, weed density, or waveband. Soybean exhibited overall lower reflectance intensity than Palmer amaranth across all wavebands. The reflectance of both species within blue, green, red, and red-edge wavebands declined as the season progressed, while reflectance in NIR increased. Near infrared and red-edge wavebands were shown to be the most useful for species discrimination and maintained their utility at most weed densities. Palmer amaranth weed densities were found to be spectrally distinct from one another in all wavebands, with greatest distinction when using the red, NIR and red-edge wavebands. Supervised classification in a two-class system was consistently able to discriminate between Palmer amaranth and soybean with at least 80% overall accuracy. The incorporation of a weed density component into these classifications introduced an error of 65% or greater into these classifications. Reducing the number of classes in a supervised classification system could improve the accuracy of discriminating between Palmer amaranth and soybean.}, number={10}, journal={AGRONOMY-BASEL}, author={Sanders, John T. and Jones, Eric A. L. and Austin, Robert and Roberson, Gary T. and Richardson, Robert J. and Everman, Wesley J.}, year={2021}, month={Oct} } @article{schwartz-lazaro_shergill_evans_bagavathiannan_beam_bish_bond_bradley_curran_davis_et al._2021, title={Seed-shattering phenology at soybean harvest of economically important weeds in multiple regions of the United States. Part 1: Broadleaf species}, volume={69}, ISSN={["1550-2759"]}, DOI={10.1017/wsc.2020.80}, abstractNote={Abstract}, number={1}, journal={WEED SCIENCE}, author={Schwartz-Lazaro, Lauren M. and Shergill, Lovreet S. and Evans, Jeffrey A. and Bagavathiannan, Muthukumar V and Beam, Shawn C. and Bish, Mandy D. and Bond, Jason A. and Bradley, Kevin W. and Curran, William S. and Davis, Adam S. and et al.}, year={2021}, month={Jan}, pages={95–103} } @article{schwartz-lazaro_shergill_evans_bagavathiannan_beam_bish_bond_bradley_curran_davis_et al._2021, title={Seed-shattering phenology at soybean harvest of economically important weeds in multiple regions of the United States. Part 2: Grass species}, volume={69}, ISSN={["1550-2759"]}, DOI={10.1017/wsc.2020.79}, abstractNote={Abstract}, number={1}, journal={WEED SCIENCE}, author={Schwartz-Lazaro, Lauren M. and Shergill, Lovreet S. and Evans, Jeffrey A. and Bagavathiannan, Muthukumar V and Beam, Shawn C. and Bish, Mandy D. and Bond, Jason A. and Bradley, Kevin W. and Curran, William S. and Davis, Adam S. and et al.}, year={2021}, month={Jan}, pages={104–110} } @article{schwartz-lazaro_shergill_evans_bagavathiannan_beam_bish_bond_bradley_curran_davis_et al._2021, title={Seed-shattering phenology at soybean harvest of economically important weeds in multiple regions of the United States. Part 3: Drivers of seed shatter}, ISSN={["1550-2759"]}, DOI={10.1017/wsc.2021.74}, abstractNote={Abstract}, journal={WEED SCIENCE}, author={Schwartz-Lazaro, Lauren M. and Shergill, Lovreet S. and Evans, Jeffrey A. and Bagavathiannan, Muthukumar V and Beam, Shawn C. and Bish, Mandy D. and Bond, Jason A. and Bradley, Kevin W. and Curran, William S. and Davis, Adam S. and et al.}, year={2021}, month={Nov} } @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}, 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{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={Abstract}, 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{frisvold_albright_ervin_owen_norsworthy_dentzman_hurley_jussaume_gunsolus_everman_2020, title={Do farmers manage weeds on owned and rented land differently? Evidence from US corn and soybean farms}, volume={76}, ISSN={["1526-4998"]}, DOI={10.1002/ps.5737}, abstractNote={Abstract}, number={6}, journal={PEST MANAGEMENT SCIENCE}, author={Frisvold, George B. and Albright, Joshua and Ervin, David E. and Owen, Micheal D. K. and Norsworthy, Jason K. and Dentzman, Katherine E. and Hurley, Terrance M. and Jussaume, Raymond A. and Gunsolus, Jeffrey L. and Everman, Wesley}, year={2020}, month={Jun}, pages={2030–2039} } @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={Abstract}, 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{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={Abstract}, 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{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={Abstract}, 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{acharya_thomas n. o'quinn_everman_mehl_2019, title={Effectiveness of Fungicides and Their Application Timing for the Management of Sorghum Foliar Anthracnose in the Mid-Atlantic United States}, volume={103}, ISSN={["1943-7692"]}, DOI={10.1094/PDIS-10-18-1867-RE}, abstractNote={ Sorghum anthracnose (Colletotrichum sublineola) reduces grain yield up to 50% but suggested management tactics have not yet been developed for the mid-Atlantic United States, where warm, wet conditions favor disease. Under factorial arrangement, five fungicides plus a nontreated control and four application timings were compared for foliar anthracnose control, yield, and profitability of fungicide use in grain sorghum over eight site-years in Virginia and North Carolina. Anthracnose severity was rated at the hard dough stage, and grain yield was determined at harvest. Every percent increase in disease severity resulted in yield losses of 27 to 85 kg/ha. Pyraclostrobin and pyraclostrobin plus fluxapyroxad reduced anthracnose (P < 0.01), and three applications resulted in less disease and greater yield compared with single applications (P < 0.01). However, three applications exceed the labeled maximum application for the fungicides and are not economical. Among single applications, boot or flowering timings reduced disease, and flowering applications resulted in the overall greatest yield. Results suggest that when disease onset occurs at or prior to boot, a single application of pyraclostrobin-containing fungicide at or just prior to flowering reduces anthracnose, protects yield, and increases income. However, when disease is absent or severity is low prior to flowering, fungicide application may not be profitable. }, number={11}, journal={PLANT DISEASE}, author={Acharya, Bhupendra and Thomas N. O'Quinn and Everman, Wesley and Mehl, Hillary L.}, year={2019}, month={Nov}, pages={2804–2811} } @article{ervin_breshears_frisvold_hurley_dentzman_gunsolus_jussaume_owen_norsworthy_al mamun_et al._2019, title={Farmer Attitudes Toward Cooperative Approaches to Herbicide Resistance Management: A Common Pool Ecosystem Service Challenge}, volume={157}, ISSN={["1873-6106"]}, DOI={10.1016/j.ecolecon.2018.11.023}, abstractNote={Dramatic growth in herbicide-resistant (HR) weeds in the United States threatens farm profitability and may undercut environmentally beneficial farming practices. When HR weeds move across farm boundaries due to ecological processes or human action, a common pool resource challenge emerges, requiring farmer cooperation to manage such weeds effectively. We investigate the scope for cooperative management using responses to a national survey on HR weed issues to test a recursive model of three preconditions for collective action: (1) concern about HR weeds migrating from nearby lands; (2) communication with neighbors about HR weeds; and (3) belief that cooperation is necessary for effective resistance management. Results suggest that farmers who relied more on Extension educators regarding weed management, were more likely to satisfy each precondition. Further, concern about weeds resistant to multiple herbicides as well as concern about HR weed mobility positively influence concern about migration and views toward cooperation. Farmer time constraints and "techno-optimism" (a belief that herbicide discoveries will solve resistance problems) detract from the perceived need for cooperative approaches. A different set of factors significantly affect each precondition, suggesting heterogeneity in the underlying casual mechanisms. The findings can help tailor collective action to different socio-ecological settings experiencing HR weed resistance issues.}, journal={ECOLOGICAL ECONOMICS}, author={Ervin, David E. and Breshears, Elise H. and Frisvold, George B. and Hurley, Terrance and Dentzman, Katherine E. and Gunsolus, Jeffrey L. and Jussaume, Raymond A. and Owen, Micheal D. K. and Norsworthy, Jason K. and Al Mamun, Mustofa Mahmud and et al.}, year={2019}, month={Mar}, pages={237–245} } @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={Abstract}, 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={Abstract}, 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{sanders_everman_austin_roberson_richardson_2019, title={Weed species differentiation using spectral reflectance and image classification}, volume={11007}, ISSN={["1996-756X"]}, url={http://dx.doi.org/10.1117/12.2519306}, DOI={10.1117/12.2519306}, abstractNote={Advancements in efficient unmanned aerial platforms and affordable sensors has led to renewed interest in remote sensing by agricultural producers and land managers for use as an efficient and convenient method of evaluating crop status and pest issues in their fields. For remote sensing to be employed as a viable and widespread tool for weed management, the accurate detection of distinct weed species must be possible through the use of analytical procedures on the resultant imagery. Additionally, the remote sensing platform and subsequent analysis must be capable of identifying these species across a wide range of heights. In 2017, a field study was performed to identify any weed height thresholds on the accurate detection and subsequent classification of three common broadleaf weed species in the southeastern United States: Palmer amaranth (Amaranthus palmeri), common ragweed (Ambrosia artemisiifolia) and sicklepod Senna obtusifolia) as well as the classification accuracy of image classifications performed on the species scale. Pots of the three species at heights of 5, 10, 15, and 30 cm were randomly arranged in a grid and 5-band multispectral imagery was collected at 15 m. Image analysis was used to identify the spectral reflectance behavior of the weed species and height combinations and to evaluate the accuracy of species based supervised classifications involving the three species. Supervised classification was able to discriminate between the three weed species with between 24-100% accuracy depending on height and species. Palmer amaranth classification accuracy was consistently 100%. Increased height of sicklepod and common ragweed plants did not reliably confer improved accuracy but the species were correctly identified with at least 24% and 60% accuracy, respectively.}, journal={ADVANCED ENVIRONMENTAL, CHEMICAL, AND BIOLOGICAL SENSING TECHNOLOGIES XV}, author={Sanders, J. T. and Everman, W. J. and Austin, R. and Roberson, G. T. and Richardson, R. J.}, year={2019} } @article{besancon_penner_everman_2018, title={Reduced Translocation Is Associated with Antagonism of Glyphosate by Glufosinate in Giant Foxtail (Setaria faberi) and Velvetleaf (Abutilon theophrasti)}, volume={66}, ISSN={["1550-2759"]}, DOI={10.1017/wsc.2017.72}, abstractNote={Previous reports have underscored antagonism that may result from mixing glyphosate and glufosinate across a wide range of application rates and for various broadleaf and grass weed species, but no investigation has been conducted to characterize glyphosate absorption and translocation when combined with glufosinate. The objectives of this study were to evaluate herbicide efficacy and assess herbicide interaction and physiological response with combinations of glyphosate and glufosinate on common lambsquarters, velvetleaf, and giant foxtail. Greenhouse studies to determine interaction resulted in strong and persistent antagonism between glyphosate at 110 and 220 g ae ha−1and glufosinate at 20 or 40 g ae ha−1in giant foxtail, whereas only transient and reduced antagonism was noted for velvetleaf and common lambsquarters. Combining glyphosate and glufosinate increased the maximum absorption of glyphosate by 9% and 23% in velvetleaf and giant foxtail, respectively, compared with glyphosate alone. In velvetleaf, averaged over time, only 2.6% of the applied radioactivity translocated out of the treated leaf when glufosinate was mixed with glyphosate compared with 9.9% when glyphosate was applied alone. In giant foxtail, 21.6% of the [14C]glyphosate translocated out of the treated leaf when glufosinate was mixed with glyphosate compared with 52.4% when glyphosate was applied alone. Conversely, no change in the radioactive pattern of translocation was noted for common lambsquarters. These results suggest that reduced translocation of glyphosate is the physiological mechanism responsible for the antagonism observed between glyphosate and glufosinate in giant foxtail and, to a lesser extent, in velvetleaf.}, number={2}, journal={WEED SCIENCE}, author={Besancon, Thierry E. and Penner, Donald and Everman, Wesley J.}, year={2018}, pages={159–167} } @article{bagavathiannan_everman_govindasamy_dille_jugulam_norsworthy_2018, title={Weed management in sorghum cultivation}, volume={31}, ISBN={["978-1-78676-120-0"]}, ISSN={["2059-6944"]}, DOI={10.19103/AS.2017.0015.18}, journal={ACHIEVING SUSTAINABLE CULTIVATION OF SORGHUM, VOL 1: GENETICS, BREEDING AND PRODUCTION TECHNIQUES}, author={Bagavathiannan, M. and Everman, W. and Govindasamy, P. and Dille, A. and Jugulam, M. and Norsworthy, J.}, year={2018}, pages={465–482} } @article{besançon_jennings_everman_2017, title={Absorption, Translocation, and Metabolism of Halosulfuron in Cucumber, Summer Squash, and Selected Weeds}, volume={65}, ISSN={1550-2759}, url={http://dx.doi.org/10.1017/WSC.2017.15}, DOI={10.1017/WSC.2017.15}, abstractNote={Greenhouse studies were conducted to investigate the absorption, translocation, and metabolism of foliar-applied [14C]halosulfuron-methyl in cucumber, summer squash, pitted morningglory, and velvetleaf. Cucumber and summer squash were treated at the 4-leaf stage, whereas velvetleaf and pitted morningglory were treated at 10 cm. All plants were collected at 4, 24, 48, and 72 h after treatment (HAT) for absorption and translocation studies and an additional 96-HAT interval was included in the metabolism study. Absorption did not exceed 45% in summer squash, whereas it plateaued around 60% in velvetleaf and cucumber and reached 80% in pitted morningglory 72 HAT. None of the four species translocated more than 23% of absorbed halosulfuron out of the treated leaf. Translocation in cucumber and summer squash was predominantly basipetal, while acropetal movement prevailed in velvetleaf. No significant direction of movement was observed for pitted morningglory. Negligible translocation occurred toward the roots, regardless of plant species. Of the total amount of [14C]halosulfuron-methyl absorbed into the plants at 96 HAT, more than 80% remained in the form of the parent compound in velvetleaf, summer squash, and pitted morningglory, whereas less than 20% was detected in cucumber. Rapid and high herbicide metabolism may explain cucumber tolerance to halosulfuron-methyl, while lack of metabolism contributes to summer squash and velvetleaf susceptibility. Pitted morningglory tolerance may be due to limited translocation associated with some level of metabolism, but further research would be needed to investigate other potential causes.}, number={4}, journal={Weed Science}, publisher={Cambridge University Press (CUP)}, author={Besançon, Thierry. E. and Jennings, Katherine M. and Everman, Wesley J.}, year={2017}, month={Jun}, pages={461–467} } @article{besançon_heiniger_weisz_everman_2017, title={Grain Sorghum and Palmer Amaranth (Amaranthus palmeri) Response to Herbicide Programs and Agronomic Practices}, volume={31}, ISSN={0890-037X 1550-2740}, url={http://dx.doi.org/10.1017/WET.2017.53}, DOI={10.1017/WET.2017.53}, abstractNote={Weed control remains a major challenge for economically viable grain sorghum production in the southeastern United States due to crop sensitivity to weed competition during early growth stages. Field experiments were conducted in 2012 and 2013 to determine the effects of grain sorghum row spacing, population density, and herbicide programs on Palmer amaranth control, crop growth, and grain yield. Treatments included row spacings of 19, 38, and 76 cm; grain sorghum population densities of 99,000, 198,000, 297,000, and 396,000 plants ha−1; and three herbicide programs: (1) a nontreated control, (2)S-metolachlor at 1,410 g ai ha−1plus atrazine at 1,820 g ha−1PRE, and (3)S-metolachlor at 1,070 g ha−1plus atrazine at 1,380 g ha−1PRE followed by 2,4 D at 330 g ha−1POST. Palmer amaranth control benefited from the addition of a POST herbicide and from crop density ≥297,000 plants ha−1. Under weedy conditions, Palmer amaranth density was not affected by narrower row spacing or increased crop density, whereas its dry biomass was reduced by 33% with 19 and 38 compared to 76 cm rows, and by 43% with ≥297,000 vs 99,000 plants ha−1. Row spacing had no effect on light interception by the crop canopy. However, crop density influenced canopy closure with maximum light interception occurring one and a half weeks earlier for density ≥297,000 plants ha−1. Yield increased by 18% for 19 vs 38 and 76 cm rows, whereas grain crop density had no effect. Overall, these results indicate that the combination of row spacing≤30 cm and crop density ≥297,000 plants ha−1provided at least 97% Palmer amaranth control in the absence of POST application and reduced its biomass by 32% in nontreated plots compared to 76 cm row spacing and crop density≤198,000 plants ha−1.}, number={6}, journal={Weed Technology}, publisher={Cambridge University Press (CUP)}, author={Besançon, Thierry E. and Heiniger, Ronnie W. and Weisz, Randy and Everman, Wesley J.}, year={2017}, month={Sep}, pages={781–792} } @article{soltani_dille_burke_everman_vangessel_davis_sikkema_2017, title={Perspectives on Potential Soybean Yield Losses from Weeds in North America}, volume={31}, ISSN={["1550-2740"]}, DOI={10.1017/wet.2016.2}, abstractNote={Weeds are one of the most significant, and controllable, threats to crop production in North America. Monetary losses because of reduced soybean yield and decreased quality because of weed interference, as well as costs of controlling weeds, have a significant economic impact on net returns to producers. Previous Weed Science Society of America (WSSA) Weed Loss Committee reports, as chaired by Chandler (1984) and Bridges (1992), provided snapshots of the comparative crop yield losses because of weeds across geographic regions and crops within these regions after the implementation of weed control tactics. This manuscript is a second report from the current WSSA Weed Loss Committee on crop yield losses because of weeds, specifically in soybean. Yield loss estimates were determined from comparative observations of soybean yields between the weedy control and plots with greater than 95% weed control in studies conducted from 2007 to 2013. Researchers from each US state and Canadian province provided at least three and up to ten individual comparisons for each year, which were then averaged within a year, and then averaged over the seven years. These percent yield loss values were used to determine total soybean yield loss in t ha−1and bu acre−1based on average soybean yields for each state or province as well as current commodity prices for a given year as summarized by USDA-NASS (2014) and Statistics Canada (2015). Averaged across 2007 to 2013, weed interference in soybean caused a 52.1% yield loss. Based on 2012 census data in the US and Canada soybean was grown on 30,798,512 and 1,679,203 hectares with production of 80 million and 5 million tonnes, respectively. Using an average soybean price across 2007 to 2013 of US $389.81 t−1($10.61 bu−1), farm gate value would be reduced by US $16.2 billion in the US and $1.0 billion in Canada annually if no weed management tactics were employed.}, number={1}, 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={2017}, pages={148–154} } @article{besancon_heiniger_weisz_everman_2017, title={Weed Response to Agronomic Practices and Herbicide Strategies in Grain Sorghum}, volume={109}, ISSN={["1435-0645"]}, DOI={10.2134/agronj2016.06.0363}, abstractNote={Core Ideas High sorghum density and narrow row spacing reduce biomass of troublesome weeds. High spatial crop uniformity extends large crabgrass and sicklepod control over time. Optimized crop density and row width may limit the need for postemergence herbicide in sorghum. }, number={4}, journal={AGRONOMY JOURNAL}, author={Besancon, Thierry and Heiniger, Ronnie and Weisz, Randy and Everman, Wesley}, year={2017}, pages={1642–1650} } @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{gholkar_mueller_rountree_2016, title={Power Tuning HPC Jobs on Power-Constrained Systems}, DOI={10.1145/2967938.2967961}, abstractNote={As we approach the exascale era, power has become a primary bottleneck. The US Department of Energy has set a power constraint of 20MW on each exascale machine. To be able achieve one exaflop under this constraint, it is necessary that we use power intelligently to maximize performance under a power constraint. Most production-level parallel applications that run on a supercomputer are tightly-coupled parallel applications. A naϊve approach of enforcing a power constraint for a parallel job would be to divide the job's power budget uniformly across all the processors. However, previous work has shown that a power capped job suffers from performance variation of otherwise identical processors leading to overall sub-optimal performance. We propose a 2-level hierarchical variation-aware approach of managing power at machine-level. At the macro level, PPartition partitions a machine's power budget across jobs to assign a power budget to each job running on the system such that the machine never exceeds its power budget. At the micro level, PTune makes job-centric decisions by taking the performance variation into account. For every moldable job, PTune determines the optimal number of processors, the selection of processors and the distribution of the job's power budget across them, with the goal of maximizing the job's performance under its power budget. Experiments show that, at the micro level, PTune achieves a performance improvement of up to 29% compared to a naϊve approach. PTune does not lead to any performance degradation, yet frees up almost 40% of the processors for the same performance as that of the naϊve approach under a hard power bound. At the macro level, PPartition is able to achieve a throughput improvement of 5-35% compared to uniform power distribution.}, journal={2016 INTERNATIONAL CONFERENCE ON PARALLEL ARCHITECTURE AND COMPILATION TECHNIQUES (PACT)}, author={Gholkar, Neha and Mueller, Frank and Rountree, Barry}, year={2016}, pages={179–190} } @article{israel_everman_richardson_2015, title={Aminocyclopyrachlor Absorption and Translocation in Three Aquatic Weeds}, volume={63}, ISSN={["1550-2759"]}, DOI={10.1614/ws-d-14-00020.1}, abstractNote={Studies were conducted to evaluate 14C-aminocyclopyrachlor absorption and translocation in alligatorweed, waterhyacinth, and waterlettuce. Alligatorweed plants were treated at the seven-node stage, waterhyacinth was treated at the five-leaf stage, and waterlettuce was treated at the eight-leaf stage. All plants were pretreated with nonlabeled aminocyclopyrachlor at 0.14 kg ai ha−1 with 1% (v/v) methylated seed oil (MSO). 14C-aminocyclopyrachlor was then applied to a protected leaf, and plants were harvested at 1, 2, 4, 12, 24, and 96 h after treatment (HAT). Radioactivity was determined in the treated leaf, shoots above treated leaf, shoots below treated leaf, roots, and growing solution. Absorption was rapid in all species and reached a maximum of 73, 72, and 73% of applied radioactivity for alligatorweed, waterhyacinth, and waterlettuce, respectively. In alligatorweed at 96 HAT, 43% of absorbed carbon-14 (14C) was translocated to shoots above the treated leaf and 17% was translocated to lower shoot tissue. In waterhyacinth at 96 HAT, 56% of absorbed 14C remained in the treated leaf, whereas 14 and 13% were found in parts above and below the treated leaf, respectively. In waterlettuce at 96 HAT, 50 and 33% of absorbed radioactivity was located above the treated leaf and in the growing solution, respectively. The low recovery of aminocyclopyrachlor in alligatorweed roots and growing solution might explain regrowth potential after herbicide treatment. These results also indicate that the lack of waterlettuce control with aminocyclopyrachlor is not due to reduced absorption or translocation.}, number={1}, journal={WEED SCIENCE}, author={Israel, Trevor D. and Everman, Wesley J. and Richardson, Robert J.}, year={2015}, pages={248–253} } @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} } @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{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} } @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{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{lewis_roten_everman_gannon_richardson_yelverton_2013, title={Absorption, Translocation, and Metabolism of Aminocyclopyrachlor in Tall Fescue (Lolium arundinaceum)}, volume={61}, ISSN={["1550-2759"]}, DOI={10.1614/ws-d-12-00189.1}, abstractNote={Synthetic auxin herbicides are commonly used in forage, pasture, range, and turfgrass settings for dicotyledonous weed control. Aminocyclopyrachlor (AMCP) is a newly developed pyrimidine carboxylic acid with a chemical structure and mode of action similar to the pyridine carboxylic acids—aminopyralid, clopyralid, and picloram. Injury to sensitive dicotyledonous plants has been observed following exposure to monocotyledonous plant material previously treated with pyridine compounds. The absorption, translocation, and metabolism of AMCP has been documented in susceptible broadleaf weeds; however, no information is available, to our knowledge, regarding AMCP fate in tolerant Poaceae, which may serve as the vector for off-target plant injury. Based on this premise, research was conducted to characterize absorption, translocation, and metabolism of AMCP in tall fescue.14C-AMCP was applied to single tiller tall fescue plant foliage under controlled laboratory conditions at North Carolina State University (Raleigh, NC). Radiation was quantified in leaf wash, treated leaf, foliage, crown, roots, and root exudates at 3, 12, 24, 48, 96, and 192 h after treatment (HAT).14C-AMCP was rapidly absorbed by tall fescue, reaching 38 and 68% at 3 and 48 HAT, respectively. Translocation of14C-AMCP was limited to the foliage, which reached maximum translocation (34%) at 96 HAT. Most of the recovered14C-AMCP remained in the leaf wash, treated leaf, or foliage, whereas minimal radiation was detected in the crown, roots, or root exudates throughout the 192-h period. No AMCP metabolism was observed in tall fescue through the 192 HAT. These data suggest AMCP applied to tall fescue can remain bioavailable, and mishandling treated plant material could result in off-target injury.}, number={3}, journal={WEED SCIENCE}, author={Lewis, Dustin F. and Roten, Rory L. and Everman, Wesley J. and Gannon, Travis W. and Richardson, Robert J. and Yelverton, Fred H.}, year={2013}, pages={348–352} } @article{lindsey_renner_everman_2013, title={Cured Dairy Compost Influence on Weed Competition and on 'Snowden' Potato Yield}, volume={27}, ISSN={["1550-2740"]}, DOI={10.1614/wt-d-12-00124.1}, abstractNote={Potatoes are an important global food crop typically produced in high-input systems in temperate zones. Growers that have access to compost may use it to improve soil health and increase tuber yields, but compost may also increase weed competition by increasing early-season water availability and weed growth. A field study at the Michigan State University Montcalm Research farm in 2010 and 2011 investigated the impact of compost on weed competition in potato. Potatoes were grown in field plots with 0, 4,000, or 8,000 kg carbon (C) ha−1of compost under weed-free conditions, and in competition with common lambsquarters, giant foxtail, and hairy nightshade. Compost did not increase biomass or seed production of any weed species. Giant foxtail and hairy nightshade at 5.3 plants per meter of row reduced potato yield by 20%; common lambsquarters reduced yield by 45%. The yield reduction by giant foxtail and hairy nightshade was due to a decrease in tuber bulking, whereas yield reductions from common lambsquarters were a result of lower tuber set and bulking. Potato yield increased 5 to 15% in compost compared to non-compost treatments; tuber specific gravity decreased by 0.3% in composted treatments. Across weed densities, elevated soil potassium levels in the 8,000 kg C ha−1composted treatment may have increased potato yield and decreased tuber specific gravity.}, number={2}, journal={WEED TECHNOLOGY}, author={Lindsey, Alexander J. and Renner, Karen A. and Everman, Wesley J.}, year={2013}, pages={378–388} } @article{lindsey_warncke_steinke_everman_2013, title={Fertilizer and Population Affects Nitrogen Assimilation of Common Lambsquarters (Chenopodium album) and Redroot Pigweed (Amaranthus retroflexus)}, volume={61}, ISSN={["0043-1745"]}, DOI={10.1614/ws-d-12-00094.1}, abstractNote={Weed growth and N assimilation usually increase with N application rate. With the increasing price of N fertilizer, a better understanding N assimilation by weeds is necessary to maximize economic return. Total plant yield is generally independent of population density, except when plants are very small or at very low population density. If plant yield is independent of population density, weed N assimilation may also be independent of population density. However, the effect of weed population density on N assimilation has not been thoroughly investigated. A 2011 controlled-environment study was established in East Lansing, MI, to evaluate the effect of weed population density and N application rate on growth and N assimilation by common lambsquarters and redroot pigweed. Study factors included four weed densities (1, 2, 4, and 8 plants pot−1), three N application rates (0, 67, and 134 kg N ha−1), and two weed species (redroot pigweed and common lambsquarters). Weeds were destructively harvested 3 wk after emergence, and shoot height, biomass, total N concentration, N use efficiency, and N assimilation were measured. Redroot pigweed was taller, had greater shoot biomass, and a greater shoot N assimilation than did common lambsquarters. With similar environmental conditions, redroot pigweed is expected to be more competitive than common lambsquarters. Shoot N assimilation increased with increasing weed population density, indicating that N assimilation was not independent of population density 3 wk after emergence because weeds were small or at low population density.}, number={1}, journal={WEED SCIENCE}, author={Lindsey, Laura E. and Warncke, Darryl D. and Steinke, Kurt and Everman, Wesley J.}, year={2013}, pages={131–135} } @article{lindsey_everman_chomas_kells_2012, title={Evaluation of Application Program and Timing in Herbicide-Resistant Corn}, volume={26}, ISSN={["1550-2740"]}, DOI={10.1614/wt-d-12-00012.1}, abstractNote={Field studies were conducted from 2007 to 2009 in East Lansing, MI to evaluate three residual herbicide programs, three POST herbicide application timings, and two POST herbicides in glyphosate- and glufosinate-resistant corn. Herbicide programs included a residual PRE-applied herbicide followed by (fb) POST application (residual fb POST), a residual herbicide tank-mixed with a POST herbicide (residual + POST), and a nonresidual POST. Three POST herbicide application timings included early POST (EP), mid-POST (MP), and late POST (LP) at an average corn growth stage of V3/V4, V4/V5, and V5/V6, respectively. The two POST herbicides evaluated were glyphosate and glufosinate. Control of common lambsquarters and giant foxtail was evaluated 28 d after the LP application. Glyphosate often provided greater weed control than glufosinate. The LP application resulted in greater giant foxtail control compared with the EP application timing, which may be attributed to control of late-emerging weeds. The EP application timing improved common lambsquarters control compared with the LP application timing. The residual + POST program resulted in greater weed control compared with the residual fb POST program in all years. The effect of residual herbicide program, POST herbicide, and POST application timing on corn grain yield varied by year. In 2007, the use of glyphosate resulted in higher grain yield compared with glufosinate. In 2008, corn grain yield was the highest in the PRE fb POST program and with POST applications at EP and MP. To provide the most consistent weed control and minimize the likelihood of grain yield reductions, a PRE fb POST program applied at EP or MP is recommended.}, number={4}, journal={WEED TECHNOLOGY}, author={Lindsey, Laura E. and Everman, Wesley J. and Chomas, Andrew J. and Kells, James J.}, year={2012}, pages={617–621} } @article{min_dietz_everman_chomas_kells_leep_2012, title={Glyphosate-Resistant Alfalfa Response to Harvest Frequency and Weed Management}, volume={26}, ISSN={["1550-2740"]}, DOI={10.1614/wt-d-11-00103.1}, abstractNote={Glyphosate-resistant (GR) alfalfa offers growers new options for weed control in alfalfa. One potential benefit of using GR alfalfa is increased longevity of an alfalfa stand under frequent harvests. It was hypothesized that GR alfalfa would have a greater longevity because of removal of weed interference with minimal crop injury. To study GR alfalfa yield, weed invasion, alfalfa stand persistence, and relative forage quality (RFQ), a field experiment with three weed control methods (no herbicide, glyphosate, and hexazinone) under two harvest frequencies (high and moderate) was established in August 2003 at the Michigan State University Agronomy Farm in East Lansing, MI. Forage yield of established alfalfa was not adversely affected by herbicide treatments. There were no differences in weed biomass between alfalfa treated with glyphosate and that treated with hexazinone, except in 2007. Average GR alfalfa stand density decreased approximately 90% (from 236 to 27 plant m−2), and yield decreased approximately 30% (from 11.04 to 7.87 Mg ha−1) during the 7-yr period (2004 to 2010) of the experiment. Stand density of GR alfalfa showed natural thinning during the 7-yr period regardless of harvest intensity or herbicide treatment. In most production years (4 out of 5 yr), relative forage quality of GR alfalfa was higher under a high-intensity harvesting system (4 to 5 harvests yr−1) than it was with a moderate intensity harvesting system (3 to 4 harvests yr−1). Relative forage quality was not affected by weed removal with herbicides in most years. Weed removal and harvest intensity in established GR alfalfa had no effect on stand persistence.}, number={3}, journal={WEED TECHNOLOGY}, author={Min, Doo-Hong and Dietz, Timothy S. and Everman, Wesley J. and Chomas, Andrew J. and Kells, James J. and Leep, Richard H.}, year={2012}, pages={399–404} } @article{everman_mayhew_burton_york_wilcut_2009, title={Absorption, Translocation, and Metabolism of C-14-Glufosinate in Glufosinate-Resistant Corn, Goosegrass (Eleusine indica), Large Crabgrass (Digitaria sanguinalis), and Sicklepod (Senna obtusifolia)}, volume={57}, ISSN={["1550-2759"]}, DOI={10.1614/WS-08-089.1}, abstractNote={Greenhouse studies were conducted to evaluate14C-glufosinate absorption, translocation, and metabolism in glufosinate-resistant corn, goosegrass, large crabgrass, and sicklepod. Glufosinate-resistant corn plants were treated at the four-leaf stage, whereas goosegrass, large crabgrass, and sicklepod were treated at 5, 7.5, and 10 cm, respectively. All plants were harvested at 1, 6, 24, 48, and 72 h after treatment (HAT). Absorption was less than 20% at all harvest intervals for glufosinate-resistant corn, whereas absorption in goosegrass and large crabgrass increased from approximately 20% 1 HAT to 50 and 76%, respectively, 72 HAT. Absorption of14C-glufosinate was greater than 90% 24 HAT in sicklepod. Significant levels of translocation were observed in glufosinate-resistant corn, with14C-glufosinate translocated to the region above the treated leaf and the roots up to 41 and 27%, respectively. No significant translocation was detected in any of the weed species at any harvest timing. Metabolites of14C-glufosinate were detected in glufosinate-resistant corn and all weed species. Seventy percent of14C was attributed to glufosinate metabolites 72 HAT in large crabgrass. Less metabolism was observed for sicklepod, goosegrass, and glufosinate-resistant corn, with metabolites composing less than 45% of detectable radioactivity 72 HAT.}, number={1}, journal={WEED SCIENCE}, author={Everman, Wesley J. and Mayhew, Cassandra R. and Burton, James D. and York, Alan C. and Wilcut, John W.}, year={2009}, pages={1–5} } @article{everman_thomas_burton_york_wilcut_2009, title={Absorption, Translocation, and Metabolism of Glufosinate in Transgenic and Nontransgenic Cotton, Palmer Amaranth (Amaranthus palmeri), and Pitted Morningglory (Ipomoea lacunosa)}, volume={57}, ISSN={["1550-2759"]}, DOI={10.1614/WS-09-015.1}, abstractNote={Greenhouse studies were conducted to evaluate absorption, translocation, and metabolism of14C-glufosinate in glufosinate-resistant cotton, nontransgenic cotton, Palmer amaranth, and pitted morningglory. Cotton plants were treated at the four-leaf stage, whereas Palmer amaranth and pitted morningglory were treated at 7.5 and 10 cm, respectively. All plants were harvested at 1, 6, 24, 48, and 72 h after treatment (HAT). Absorption of14C-glufosinate was greater than 85% 24 h after treatment in Palmer amaranth. Absorption was less than 30% at all harvest intervals for glufosinate-resistant cotton, nontransgenic cotton, and pitted morningglory. At 24 HAT, 49 and 12% of radioactivity was translocated to regions above and below the treated leaf, respectively, in Palmer amaranth. Metabolites of14C-glufosinate were detected in all crop and weed species. Metabolism of14C-glufosinate was 16% or lower in nontransgenic cotton and pitted morningglory; however, metabolism rates were greater than 70% in glufosinate-resistant cotton 72 HAT. Intermediate metabolism was observed for Palmer amaranth, with metabolites comprising 20 to 30% of detectable radioactivity between 6 and 72 HAT.}, number={4}, journal={WEED SCIENCE}, author={Everman, Wesley J. and Thomas, Walter E. and Burton, James D. and York, Alan C. and Wilcut, John W.}, year={2009}, pages={357–361} } @article{everman_clewis_york_wilcut_2009, title={Weed Control and Yield with Flumioxazin, Fomesafen, and S-Metolachlor Systems for Glufosinate-Resistant Cotton Residual Weed Management}, volume={23}, ISSN={["1550-2740"]}, DOI={10.1614/WT-09-007.1}, abstractNote={Field studies were conducted near Clayton, Lewiston, and Rocky Mount, NC in 2005 to evaluate weed control and cotton response to preemergence treatments of pendimethalin alone or in a tank mixture with fomesafen, postemergence treatments of glufosinate applied alone or in a tank mixture withS-metolachlor, and POST-directed treatments of glufosinate in a tank mixture with flumioxazin or prometryn. Excellent weed control (> 91%) was observed where at least two applications were made in addition to glufosinate early postemergence (EPOST). A reduction in control of common lambsquarters (8%), goosegrass (20%), large crabgrass (18%), Palmer amaranth (13%), and pitted morningglory (9%) was observed when residual herbicides were not included in PRE or mid-POST programs. No differences in weed control or cotton lint yield were observed between POST-directed applications of glufosinate with flumioxazin compared to prometryn. Weed control programs containing three or more herbicide applications resulted in similar cotton lint yields at Clayton and Lewiston, and Rocky Mount showed the greatest variability with up to 590 kg/ha greater lint yield where fomesafen was included PRE compared to pendimethalin applied alone. Similarly, an increase in cotton lint yields of up to 200 kg/ha was observed whereS-metolachlor was included mid-POST when compared to glufosinate applied alone, showing the importance of residual herbicides to help maintain optimal yields. Including additional modes of action with residual activity preemergence and postemergence provides a longer period of weed control, which helps maintain cotton lint yields.}, number={3}, journal={WEED TECHNOLOGY}, author={Everman, Wesley J. and Clewis, Scott B. and York, Alan C. and Wilcut, John W.}, year={2009}, pages={391–397} } @article{everman_burke_clewis_thomas_wilcut_2008, title={Critical period of grass vs. broadleaf weed interference in peanut}, volume={22}, ISSN={["1550-2740"]}, DOI={10.1614/wt-07-037.1}, abstractNote={Studies were conducted to evaluate the effects of grass and broadleaf weeds on peanut growth and peanut yield. In separate studies, grass or broadleaf weeds were allowed to compete with peanut for various intervals to determine both the critical timing of weed removal and the critical weed-free period. Hand-weeding and selective herbicides were used at appropriate times to remove and terminate weed growth. These periods were then used to determine the critical period of weed control. The effects of various weedy intervals on peanut yield were also investigated. The critical period of grass weed control was found to be from 4.3 to 9 wk after planting (WAP), whereas the critical period of broadleaf weed control was from 2.6 to 8 WAP. Peanut yields decreased as weed interference intervals for both grass and broadleaf weeds increased, demonstrating the need for control of both grass and broadleaf weeds throughout much of the growing season. Nomenclature: Peanut, Arachis hypogaea L}, number={1}, journal={WEED TECHNOLOGY}, author={Everman, Wesley J. and Burke, Ian C. and Clewis, Scott B. and Thomas, Walter E. and Wilcut, John W.}, year={2008}, pages={68–73} } @article{everman_clewis_thomas_burke_wilcut_2008, title={Critical period of weed interference in peanut}, volume={22}, ISSN={["1550-2740"]}, DOI={10.1614/wt-07-052.1}, abstractNote={Field studies were conducted near Lewiston–Woodville and Rocky Mount, NC to evaluate the effects of mixed weed species on peanut yield. A combination of broadleaf and grass weeds were allowed to interfere with peanut for various intervals to determine both the critical timing of weed removal and the critical weed-free period. These periods were then combined to determine the critical period of weed control in peanut. The effects of various weedy intervals on peanut yield were also investigated. The predicted critical period of weed control, in the presence of a mixed population of weeds, was found to be from 3 to 8 wk after planting (WAP). Peanut yield decreased as weed interference intervals increased, demonstrating the need for weed control throughout much of the growing season in the presence of mixed weed populations. Nomenclature: Peanut, Arachis hypogaea L}, number={1}, journal={WEED TECHNOLOGY}, author={Everman, Wesley J. and Clewis, Scott B. and Thomas, Walter E. and Burke, Ian C. and Wilcut, John W.}, year={2008}, pages={63–67} } @article{clewis_thomas_everman_witcut_2008, title={Glufosinate-resistant corn interference in glufosinate-resistant cotton}, volume={22}, ISSN={["1550-2740"]}, DOI={10.1614/WT-07-085.1}, abstractNote={Studies were conducted at three locations in North Carolina in 2004 to evaluate density-dependent effects of glufosinate-resistant (GUR) corn on GUR cotton growth and lint yield. GUR corn was taller than GUR cotton as early as 11 d after planting, depending on location. A GUR corn density of 5.25 plant/m of crop row reduced late-season cotton height by 38, 43, and 43% at Clayton, Lewiston-Woodville, and Rocky Mount, NC, respectively, compared with weed-free cotton height. GUR corn dry biomass per meter of crop row and GUR corn seed biomass per meter of crop row decreased linearly with increasing GUR corn density at all locations. The relationship between GUR corn density and GUR cotton yield loss was described by the rectangular hyperbola model with the asymptote (a) constrained to 100% maximum yield loss. The estimated coefficient i (yield loss per unit density as density approaches zero) was 7, 5, and 6 at Clayton, Lewiston-Woodville, and Rocky Mount, respectively. Percentage of GUR cotton lint yield loss increased 4, 5, and 8 percentage points at Clayton, Lewiston-Woodville, and Rocky Mount, respectively, with each 500 g increase in weed biomass/m of crop row. The examined GUR corn densities had a significant effect on cotton yield but not as significant as many other problematic grass and broadleaf weeds. Nomenclature: Glufosinate, corn, Zea mays L. ‘Pioneer 34A55LL’ ZEAMX, cotton, Gossypium hirsutum L., ‘FM 958LL’}, number={2}, journal={WEED TECHNOLOGY}, author={Clewis, Scott B. and Thomas, Walter E. and Everman, Wesley J. and Witcut, John W.}, year={2008}, pages={211–216} } @article{everman_medlin_dirks_bauman_biehl_2008, title={The effect of postemergence herbicides on the spectral reflectance of corn}, volume={22}, ISSN={["1550-2740"]}, DOI={10.1614/WT-07-021.1}, abstractNote={Studies were conducted in 2001 and 2002 to determine the effect of POST herbicides on the spectral reflectance of corn. POST corn herbicides evaluated included 2,4-D, atrazine, bromoxynil, dicamba + diflufenzopyr, nicosulfuron, and primisulfuron. Multispectral and hyperspectral data were collected and spectral properties were analyzed using SAS procedures and MultiSpec image analysis. Corn treated with POST applications of atrazine and primisulfuron could not be distinguished from nontreated corn regardless of data type or analysis method used. 2,4-D and dicamba + diflufenzopyr were the most readily distinguished from nontreated corn plots using both hyperspectral and multispectral data.}, number={3}, journal={WEED TECHNOLOGY}, author={Everman, Wesley J. and Medlin, Case R. and Dirks, Richard D., Jr. and Bauman, Thomas T. and Biehl, Larry}, year={2008}, pages={514–522} } @article{thomas_everman_burke_koger_wilcut_2007, title={Absorption and translocation of glyphosate and sucrose in glyphosate-resistant cotton}, volume={21}, ISSN={["0890-037X"]}, DOI={10.1614/WT-06-125.1}, abstractNote={Studies were conducted to evaluate absorption and translocation of 14C-glyphosate in glyphosate-resistant (GR) cotton. Both commercial GR cotton events [glyphosate-resistant event 1, marketed as Roundup Ready®, released 1997 (GRE1), and glyphosate-resistant event 2, marketed as Roundup Ready Flex®, released 2006 (GRE2)] were evaluated at the four-leaf and eight-leaf growth stages. Plants were harvested at 1, 3, 5, and 7 d after treatment (DAT). Glyphosate absorption, as a percentage of applied, increased over time with 29 and 36% absorption at 7 DAT in four-leaf GRE1 and GRE2 cotton, respectively. In eight-leaf cotton, glyphosate absorption (33% at 7 DAT) was not different between events. Glyphosate translocation patterns were not different between events or harvest timings and exhibited a source–sink relation. Observed translocation differences between cotton growth stages were probably due to reduced glyphosate export from the treated leaf of eight-leaf cotton. An additional study compared absorption and translocation of 14C-glyphosate and 14C-sucrose in 5- and 10-leaf GRE2 cotton. Averaged over trials, 14C compounds, and growth stages, cotton absorbed 28% of the applied dose at 14 DAT. On the basis of the percentage of 14C exported out of the treated leaf, glyphosate and sucrose translocation patterns were similar, indicating that glyphosate may be used as a photoassimilate model in GRE2 cotton. Nomenclature: Glyphosate; cotton, Gossypium hirsutum L.}, number={2}, journal={WEED TECHNOLOGY}, author={Thomas, Walter E. and Everman, Wesley J. and Burke, Ian C. and Koger, Clifford H. and Wilcut, John W.}, year={2007}, pages={459–464} } @article{thomas_everman_allen_collins_wilcut_2007, title={Economic assessment of weed management systems in glufosinate-resistant, glyphosate-resistant, imidazolinone-tolerant, and nontransgenic corn}, volume={21}, ISSN={["1550-2740"]}, DOI={10.1614/WT-06-054.1}, abstractNote={Four field studies were conducted in 2004 to evaluate corn tolerance, weed control, grain yield, and net returns in glufosinate-resistant (GUR), glyphosate-resistant (GYR), imidazolinone-tolerant (IT), and nontransgenic (NT) corn with various herbicide systems. No significant differences between hybrid systems were observed for weed control. Limited corn injury (< 5%) was observed for all herbicide treatments. A single early POST (EPOST) system withoutS-metolachlor and sequential POST over the top (POT) herbicide systems, averaged over corn hybrids and PRE and late POST-directed (LAYBY) herbicide options, provide 93 and 99% control of goosegrass, respectively, and at least 83 and 97% control of Texas panicum, respectively. A single EPOST system withoutS-metolachlor, averaged over corn hybrids and LAYBY treatment options, provided at least 88% control of large crabgrass. When averaged over corn hybrid and PRE herbicide options, a sequential POT herbicide system alone provided at least 98, 99, 98, and 100 control of large crabgrass, morningglory species, Palmer amaranth, and common lambsquarters, respectively. The addition of ametryn at LAYBY to a single EPOST system withoutS-metolachlor was beneficial for improving control of morningglory species, common lambsquarters, and Palmer amaranth, depending on location. However, the observed increases (7 percentage points or less) are likely of limited biological significance. Grain yield was variable between hybrids and locations because of environmental differences. Consequently, net returns for each hybrid system within a location were also variable. Any POT system with or without ametryn at LAYBY, averaged over corn hybrid and PRE herbicide options, provided at least 101, 97, 92, and 92% yield protection at Clayton, Kinston, Lewiston, and Rocky Mount, NC, respectively. Net returns were maximized with treatments that provided excellent weed control with minimal inputs.}, number={1}, journal={WEED TECHNOLOGY}, author={Thomas, Walter E. and Everman, Wesley J. and Allen, Jayla and Collins, Jim and Wilcut, John W.}, year={2007}, pages={191–198} } @article{thomas_everman_clewis_wilcut_2007, title={Glyphosate-resistant corn interference in glyphosate-resistant cotton}, volume={21}, ISSN={["1550-2740"]}, DOI={10.1614/WT-06-007.1}, abstractNote={Studies were conducted at three locations in North Carolina in 2004 to evaluate density-dependent effects of glyphosate-resistant (GR) corn on GR cotton growth and lint yield. GR corn was taller than GR cotton as early as 25 d after planting, depending on location. A GR corn density of 5.25 plant/m of crop row reduced late season cotton height by 49, 24, and 28% at Clayton, Lewiston–Woodville, and Rocky Mount, respectively, compared to weed-free cotton height. At Clayton, GR corn dry biomass per m crop row and GR corn seed biomass per m of crop row decreased linearly with increasing corn density. The relationship between GR corn and GR cotton yield loss was described by the rectangular hyperbola model with the asymptote (a) constrained to 100% maximum yield loss. The estimated coefficient i (yield loss per unit density as density approaches zero) was 9, 5, and 5 at Clayton, Lewiston–Woodville, and Rocky Mount, respectively. The examined GR corn densities had a significant effect on cotton yield, but not as significant as many other problematic grass and broadleaf weeds. Nomenclature: Glyphosate; corn, Zea mays L., ZEAMX, ‘DKC 69-71RR’; cotton, Gossypium hirsutum L. ‘FM 989RR’, ‘ST 4892RR’.}, number={2}, journal={WEED TECHNOLOGY}, author={Thomas, Walter E. and Everman, Wesley J. and Clewis, Scott B. and Wilcut, John W.}, year={2007}, pages={372–377} } @article{thomas_everman_collins_koger_wilcut_2007, title={Rain-free requirement and physiological properties of cotton plant growth regulators}, volume={88}, ISSN={["1095-9939"]}, DOI={10.1016/j.pestbp.2006.12.002}, abstractNote={Greenhouse studies were conducted to (1) evaluate the rain-free requirement for mepiquat chloride and mepiquat chloride plus cyclanilide with and without surfactant and to (2) evaluate absorption and translocation of cyclanilide, a component of a new cotton plant growth regulator. No significant differences in the number of nodes, leaf area, and plant organ fresh and dry weight were observed with any PGR treatment and rainfall simulation combination. Both plant growth regulators responded similarly to rainfall interval. As rain-free period increased, cotton height was reduced. Based on these data, a rain-free period of 8 h is needed to maximize efficacy, regardless of the use of surfactant. Absorption of cyclanilide ranged from 11 to 15% at 3 and 48 h after treatment, respectively. Averaged over harvest intervals, 18% of the applied cyclanilide remained in the treated leaf while 1.7 and 6.5% of the applied cyclanilide was found in the above and below treated leaf tissue, respectively.}, number={3}, journal={PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY}, author={Thomas, Walter E. and Everman, Wesley J. and Collins, James R. and Koger, Clifford H. and Wilcut, John W.}, year={2007}, month={Jul}, pages={247–251} } @article{everman_burke_allen_collins_wilcut_2007, title={Weed control and yield with glufosinate-resistant cotton weed management systems}, volume={21}, DOI={10.1614/W7-06-164.1}, number={3}, journal={Weed Technology}, author={Everman, W. J. and Burke, I. C. and Allen, J. R. and Collins, J. and Wilcut, J. W.}, year={2007}, pages={695–701} } @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{everman_clewis_taylor_wilcut_2006, title={Influence of diclosulam postemergence application timing on weed control and peanut tolerance}, volume={20}, ISSN={["0890-037X"]}, DOI={10.1614/WT-05-087R1.1}, abstractNote={Field studies were conducted at Lewiston–Woodville and Rocky Mount, NC in 2001 and 2002 to evaluate weed control and peanut response to POST treatments of diclosulam at various rates and application timings. Diclosulam controlled common ragweed and entireleaf morningglory when applied within 35 d after planting (DAP). Common ragweed 61 cm tall was controlled ≥92% with 4 to 13 g ai/ha diclosulam and larger common ragweed (107 to 137 cm tall) were controlled ≥97% with 27 g/ha diclosulam. Common lambsquarters was controlled 62% or less with all diclosulam POST treatments following metolachlor applied PRE, which provided 48% control. Peanut injury was less than 15% with all diclosulam POST treatments and was transitory. In separate studies, POST diclosulam treatments did not affect peanut yield in a weed-free environment. Peanut yield in weedy environments was reduced as the diclosulam application timing was delayed because of early season weed interference. A linear relationship was observed between yield and application timing with yield decreasing as application timing was delayed. This yield response documents the importance of early season weed management for maximizing peanut yield potential. Virginia peanut varieties were not affected by different POST rates of diclosulam; however, early season peanut injury showed a linear and quadratic relationship with diclosulam rate and was less than 14% at rates as high as 71 g/ha, and was not apparent by late season.}, number={3}, journal={WEED TECHNOLOGY}, author={Everman, Wesley J. and Clewis, Scott B. and Taylor, Zachary G. and Wilcut, John W.}, year={2006}, pages={651–657} } @article{porterfield_everman_wilcut_2006, title={Soybean response to residual and in-season treatments of trifloxysulfuron}, volume={20}, ISSN={["1550-2740"]}, DOI={10.1614/WT-05-033R.1}, abstractNote={Experiments were conducted from 1998 to 2000 at Rocky Mount, NC, in weed-free environments to determine soybean tolerance to preplant (PP) applications of trifloxysulfuron and the potential for trifloxysulfuron applied preemergence (PRE) and postemergence (POST) to cotton to injure soybean grown in rotation the following year. Trifloxysulfuron at 3.75 and 7.5 g ai/ha applied PP 2 wk before seeding injured conventional soybean less than 5%, whereas no injury was observed when seeding was delayed 4 or 6 wk after PP treatment. No injury to sulfonylurea-resistant soybean (SR) was observed for any treatment. Soybean yields were not influenced by trifloxysulfuron treatment. Cotton injury was 7% or less with trifloxysulfuron applied PRE or POST at 3.75 and 7.5 g/ha. Trifloxysulfuron at 15 g/ha PRE or POST injured cotton a maximum of 14 to 18%. Trifloxysulfuron did not reduce cotton lint yields regardless of method or rate of application. Both conventional and SR soybean were not injured nor were yields influenced by trifloxysulfuron applied PRE or POST the previous year to cotton.}, number={2}, journal={WEED TECHNOLOGY}, author={Porterfield, Dunk and Everman, Wesley J. and Wilcut, John W.}, year={2006}, pages={384–388} }