@article{ye_koenning_zeng_zhuo_liao_2021, title={Molecular Characterization of an Emerging Root-Knot Nematode Meloidogyne enterolobii in North Carolina, USA}, volume={105}, ISSN={["1943-7692"]}, DOI={10.1094/PDIS-04-20-0816-RE}, abstractNote={ An emerging threat to agriculture, Meloidogyne enterolobii Yang & Eisenback, 1983, is a tropical species and considered to be the most damaging root-knot nematode (RKN) in the world because of its wide host range, aggressiveness, and ability to overcome resistance to RKN in many crops. It was first detected in the United States on ornamental plants in Florida in 2001 but has since been identified in North Carolina, South Carolina, and Louisiana. Several thousand RKN populations were collected from North Carolina field crops, ornamental plants, and turfgrasses for species identification in the Nematode Assay Laboratory in the North Carolina Department of Agriculture & Consumer Services. From 2006 to 2019, root systems showing galling symptoms were dissected under the microscope, and females were obtained for DNA analysis. When only soil samples were submitted, the second-stage juveniles or males were used instead. Molecular characterization was performed via polymerase chain reaction with species-specific primers and DNA sequencing on the ribosomal DNA 18S-ITS1-5.8S and 28S D2/D3 and mitochondrial DNA CoxII-16S. One hundred thirty-five representative RKN populations from North Carolina were characterized and identified as M. enterolobii. Six populations from China where the species was originally described were included in this study for identity confirmation and comparison. As of December 2019, M. enterolobii has been confirmed from a limited number of fields in 11 North Carolina counties: Columbus, Craven, Greene, Harnett, Johnston, Lenoir, Nash, Pitt, Sampson, Wayne, and Wilson. Currently, M. enterolobii is the most important emerging RKN species in the United States and causes severe damage to agronomic and horticultural crops, especially sweetpotato in North Carolina. }, number={4}, journal={PLANT DISEASE}, author={Ye, Weimin and Koenning, Steve R. and Zeng, Yongsan and Zhuo, Kan and Liao, Jinling}, year={2021}, month={Apr}, pages={819–831} }
 @article{mueller_wise_sisson_allen_bergstrom_bissonnette_bradley_byamukama_chilvers_collins_et al._2020, title={Corn Yield Loss Estimates Due to Diseases in the United States and Ontario, Canada, from 2016 to 2019}, volume={21}, ISSN={["1535-1025"]}, DOI={10.1094/PHP-05-20-0038-RS}, abstractNote={ Annual reductions in corn (Zea mays L.) yield caused by diseases were estimated by university Extension-affiliated plant pathologists in 26 corn-producing states in the United States and in Ontario, Canada, from 2016 through 2019. Estimated loss from each disease varied greatly by state or province and year. Gray leaf spot (caused by Cercospora zeae-maydis Tehon & E.Y. Daniels) caused the greatest estimated yield loss in parts of the northern United States and Ontario in all years except 2019, and Fusarium stalk rot (caused by Fusarium spp.) also greatly reduced yield. Tar spot (caused by Phyllachora maydis Maubl.), a relatively new disease in the United States, was estimated to cause substantial yield loss in 2018 and 2019 in several northern states. Gray leaf spot and southern rust (caused by Puccinia polysora Underw.) caused the most estimated yield losses in the southern United States. Unfavorable wet and delayed harvest conditions in 2018 resulted in an estimated 2.5 billion bushels (63.5 million metric tons) of grain contaminated with mycotoxins. The estimated mean economic loss due to reduced yield caused by corn diseases in the United States and Ontario from 2016 to 2019 was US$55.90 per acre (US$138.13 per hectare). Results from this survey provide scientists, corn breeders, government agencies, and educators with data to help inform and prioritize research, policy, and educational efforts in corn pathology and disease management. }, number={4}, journal={PLANT HEALTH PROGRESS}, author={Mueller, Daren S. and Wise, Kiersten A. and Sisson, Adam J. and Allen, Tom W. and Bergstrom, Gary C. and Bissonnette, Kaitlyn M. and Bradley, Carl A. and Byamukama, Emmanuel and Chilvers, Martin I and Collins, Alyssa A. and et al.}, year={2020}, pages={238–247} }
 @article{ruark_koenning_davis_opperman_lommel_mitchum_sit_2017, title={Soybean cyst nematode culture collections and field populations from North Carolina and Missouri reveal high incidences of infection by viruses}, volume={12}, ISSN={["1932-6203"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85011268632&partnerID=MN8TOARS}, DOI={10.1371/journal.pone.0171514}, abstractNote={Five viruses were previously discovered infecting soybean cyst nematodes (SCN; Heterodera glycines) from greenhouse cultures maintained in Illinois. In this study, the five viruses [ScNV, ScPV, ScRV, ScTV, and SbCNV-5] were detected within SCN greenhouse and field populations from North Carolina (NC) and Missouri (MO). The prevalence and titers of viruses in SCN from 43 greenhouse cultures and 25 field populations were analyzed using qRT-PCR. Viral titers within SCN greenhouse cultures were similar throughout juvenile development, and the presence of viral anti-genomic RNAs within egg, second-stage juvenile (J2), and pooled J3 and J4 stages suggests active viral replication within the nematode. Viruses were found at similar or lower levels within field populations of SCN compared with greenhouse cultures of North Carolina populations. Five greenhouse cultures harbored all five known viruses whereas in most populations a mixture of fewer viruses was detected. In contrast, three greenhouse cultures of similar descent to one another did not possess any detectable viruses and primarily differed in location of the cultures (NC versus MO). Several of these SCN viruses were also detected in Heterodera trifolii (clover cyst) and Heterodera schachtii (beet cyst), but not the other cyst, root-knot, or reniform nematode species tested. Viruses were not detected within soybean host plant tissue. If nematode infection with viruses is truly more common than first considered, the potential influence on nematode biology, pathogenicity, ecology, and control warrants continued investigation.}, number={1}, journal={PLOS ONE}, publisher={Public Library of Science (PLoS)}, author={Ruark, Casey L. and Koenning, Stephen R. and Davis, Eric L. and Opperman, Charles H. and Lommel, Steven A. and Mitchum, Melissa G. and Sit, Tim L.}, editor={Rao, A.L.N.Editor}, year={2017}, month={Jan} }
 @article{sikora_allen_wise_bergstrom_bradley_bond_brown-rytlewski_chilvers_damicone_dewolf_et al._2014, title={A Coordinated Effort to Manage Soybean Rust in North America: A Success Story in Soybean Disease Monitoring}, volume={98}, ISSN={["1943-7692"]}, DOI={10.1094/pdis-02-14-0121-fe}, abstractNote={ Existing crop monitoring programs determine the incidence and distribution of plant diseases and pathogens and assess the damage caused within a crop production region. These programs have traditionally used observed or predicted disease and pathogen data and environmental information to prescribe management practices that minimize crop loss. Monitoring programs are especially important for crops with broad geographic distribution or for diseases that can cause rapid and great economic losses. Successful monitoring programs have been developed for several plant diseases, including downy mildew of cucurbits, Fusarium head blight of wheat, potato late blight, and rusts of cereal crops. A recent example of a successful disease-monitoring program for an economically important crop is the soybean rust (SBR) monitoring effort within North America. SBR, caused by the fungus Phakopsora pachyrhizi, was first identified in the continental United States in November 2004. SBR causes moderate to severe yield losses globally. The fungus produces foliar lesions on soybean (Glycine max) and other legume hosts. P. pachyrhizi diverts nutrients from the host to its own growth and reproduction. The lesions also reduce photosynthetic area. Uredinia rupture the host epidermis and diminish stomatal regulation of transpiration to cause tissue desiccation and premature defoliation. Severe soybean yield losses can occur if plants defoliate during the mid-reproductive growth stages. The rapid response to the threat of SBR in North America resulted in an unprecedented amount of information dissemination and the development of a real-time, publicly available monitoring and prediction system known as the Soybean Rust-Pest Information Platform for Extension and Education (SBR-PIPE). The objectives of this article are (i) to highlight the successful response effort to SBR in North America, and (ii) to introduce researchers to the quantity and type of data generated by SBR-PIPE. Data from this system may now be used to answer questions about the biology, ecology, and epidemiology of an important pathogen and disease of soybean. }, number={7}, journal={PLANT DISEASE}, author={Sikora, E. J. and Allen, T. W. and Wise, K. A. and Bergstrom, G. and Bradley, C. A. and Bond, J. and Brown-Rytlewski, D. and Chilvers, M. and Damicone, J. and DeWolf, E. and et al.}, year={2014}, month={Jul}, pages={864–875} }
 @article{ye_koenning_zhuo_liao_2013, title={First Report of Meloidogyne enterolobii on Cotton and Soybean in North Carolina, United States.}, volume={97}, ISSN={["1943-7692"]}, DOI={10.1094/pdis-03-13-0228-pdn}, abstractNote={ Stunted cotton plants (Gossypium hirsutum L. cvs. PHY 375 WR and PHY 565 WR) from two separate fields near Goldsboro in Wayne County, North Carolina were collected by the NCDA&CS Agronomic Division nematode lab for nematode assay and identification in December 2011. The galls on cotton plants were very large in comparison with those commonly associated with Meloidogyne incognita Kofoid and White (Chitwood) infected cotton. In August 2012, the lab also received heavily galled roots of soybean (Glycine max (L.) Merr. cv. 7732) from Wayne and Johnston counties. Population densities of the 2nd-stage juveniles ranged from 150 to 3,800 per 500 cc soil. Female perineal patterns were similar to M. incognita, but PCR and DNA sequencing matched that of M. enterolobii Yang and Eisenback (4). DNA sequences of ribosomal DNA small subunit, internal transcribed spacer, large subunit domain 2 and 3, intergeneric spacer, RNA polymerase II large subunit, and histone gene H3, were found to be 100% homologous when comparing populations of M. enterolobii from North Carolina and China. Species identification was also confirmed using PCR by a species-specific SCAR primer set MK7-F/MK7-R (2). M. enterolobii Yang & Eisenback was described in 1983 from a population causing severe damage to pacara earpod tree (Enterolobium contortisiliquum (Vell.) Morong) in China (4). In 2004, M. mayaguensis Rammah & Hirschmann, a species described from Puerto Rico, was synonymized with M. enterolobii based on esterase phenotype and mitochondrial DNA sequence (3). M. enterolobii is considered to be a highly pathogenic species and has been reported from vegetables, ornamental plants, guava, and weeds in China, Africa, Central and South America, the Caribbean, and Florida in the United States (1,3,4). Of particular concern is its ability to develop on crop genotypes carrying root-knot-nematode resistance genes (Mi-1, Mh, Mir1, N, Tabasco, and Rk) in tobacco, tomato, soybean, potato, cowpea, sweet potato, and cotton. Consequently, this species was added to the European and Mediterranean Plant Protection Organization A2 Alert list in 2010. Two populations of M. enterolobii one from soybean and one from cotton were reared on tomato (Solanum lycopersicum L. var. lycopersicum) in a greenhouse setting. Eggs were extracted using NaOCl and inoculated, at a rate of 7,000 per 15-cm-diameter clay pot, into a sandy soil mixture (1:1 washed river sand and loamy sand). Tomato, peanut (Arachis hypogaea L.), cotton, watermelon (Citrullus lanatus (Thunb.) Matsum. & Nakai), pepper (Capsicum annuum L.), and root-knot-susceptible and -resistant tobacco (Nicotiana tabacum L. cvs. K326 and NC 70, respectively) were transplanted immediately into the infested soil with four replications. Root galls on the host differentials were evaluated after 90 days. Reproduction occurred on all hosts except for peanut, which is consistent with reports for M. enterolobii and M. incognita race 4 (4). Adult females from pepper plants used in the host differential test were sequenced on partial 18S and ITS1 region and confirmed to be M. enterlobii. To our knowledge, this is the first report of a natural infection of North Carolina field crops with M. enterolobii. }, number={9}, journal={PLANT DISEASE}, author={Ye, W. M. and Koenning, S. R. and Zhuo, K. and Liao, J. L.}, year={2013}, month={Sep}, pages={1262–1262} }
 @article{carter_koenning_burton_rzewnicki_villagarcia_bowman_arelli_2011, title={Registration of 'N7003CN' Maturity-Group-VII Soybean with High Yield and Resistance to Race 2 (HG Type 1.2.5.7-) Soybean Cyst Nematode}, volume={5}, ISSN={["1940-3496"]}, DOI={10.3198/jpr2010.09.0565crc}, abstractNote={‘N7003CN’ soybean [Glycine max (L.) Merr.] (Reg. No. CV‐502, PI 661157) was developed and released by the USDA‐ARS in 2010. It is a high‐yielding, maturity‐group (MG) VII, nontransgenic soybean cultivar adapted to the southeastern USA (30–37° N latitude). N7003CN is the first publicly released MG‐VII soybean that is resistant to race 2 (HG type 1.2.5.7) of the soybean cyst nematode (SCN; Heterodera glycines Ichinohe). Race 2 is the dominant type of SCN in North Carolina. N7003CN is also resistant to races 1 and 14 (HG types 2.3‐ and 1.3.5.6.7, respectively), is moderately resistant to races 4 and 5 (HG types 1.2.3.5.6‐ and 2.5.7‐, respectively), and appears to have partial resistance to race 3 (HG type 5.7). Molecular analysis of N7003CN identified SSR markers associated with SCN resistance genes rhg1, Rhg4, and Rhg5. During 2005–2009 in USDA Uniform Soybean Tests, N7003CN yielded 11 and 2% more than the SCN‐susceptible control cultivars ‘Haskell RR’ and ‘N7002’, respectively (46 environments). During 2005–2009 in the North Carolina State University Official Variety Trials (OVT), the yield of N7003CN was equivalent to that of the SCN‐susceptible control cultivar, ‘NC‐Raleigh’. NC‐Raleigh was the highest‐yielding MG‐VII entry in the OVT. The unusual combination of high yield and SCN race‐2 resistance in group‐VII maturity makes this cultivar potentially desirable for conventional and organic production and as breeding stock for commercial breeding.}, number={3}, journal={JOURNAL OF PLANT REGISTRATIONS}, author={Carter, T. E., Jr. and Koenning, S. R. and Burton, J. W. and Rzewnicki, P. E. and Villagarcia, M. R. and Bowman, D. T. and Arelli, P. R.}, year={2011}, month={Sep}, pages={309–317} }
 @article{jordan_barnes_corbett_bogle_johnson_shew_koenning_ye_brandenburg_2008, title={Crop Response to Rotation and Tillage in Peanut-Based Cropping Systems}, volume={100}, ISSN={["1435-0645"]}, DOI={10.2134/agronj2008.0075}, abstractNote={Production of peanut (Arachis hypogaea L.) in reduced tillage systems has increased in the United States during the past decade. However, interactions of tillage system and crop rotation have not been thoroughly investigated for large‐seeded, Virginia market type peanut. Research was conducted at two locations in North Carolina during 1999 to 2006 to compare yield of corn (Zea mays L.), cotton (Gossypium hirsutum L.), and peanut in different rotations planted in conventional and reduced tillage. Crop rotation affected peanut yield but did not affect corn or cotton yield. Increasing the number of times corn, cotton, or a combination of these crops were planted between peanut increased peanut yields. Tillage affected cotton and peanut yield but not in every year or at both locations. Yield was similar in conventional and reduced tillage in 8 of 10 comparisons (cotton) and 6 of 8 comparisons (peanut). Crop rotation and tillage did not interact for visual estimates of plant condition of peanut as a result of disease, soil parasitic nematode populations when peanut was planted during the final year of the experiment, crop yield, cumulative net return over the duration of the experiment, or bulk density in the pegging zone during the final year of the experiment. These data suggest that variation in response to rotation and tillage should be expected based on the crop and edaphic and environmental conditions. However, response to rotation and tillage most likely will be independent.}, number={6}, journal={AGRONOMY JOURNAL}, author={Jordan, David L. and Barnes, J. Steven and Corbett, Tommy and Bogle, Clyde R. and Johnson, P. Dewayne and Shew, Barbara B. and Koenning, Stephen R. and Ye, Weimin and Brandenburg, Rick L.}, year={2008}, pages={1580–1586} }
 @article{zasada_avendano_li_logan_melakeberhan_koenning_tylka_2008, title={Potential of an alkaline-stabilized biosolid to manage nematodes: Case studies on soybean cyst and root-knot nematodes}, volume={92}, ISSN={["1943-7692"]}, DOI={10.1094/PDIS-92-1-0004}, abstractNote={HomePlant DiseaseVol. 92, No. 1Potential of an Alkaline-Stabilized Biosolid to Manage Nematodes: Case Studies on Soybean Cyst and Root-Knot Nematodes PreviousNext Potential of an Alkaline-Stabilized Biosolid to Manage Nematodes: Case Studies on Soybean Cyst and Root-Knot NematodesInga A. Zasada, Felicitas Avendano, Yuncong C. Li, Terry Logan, Haddish Melakeberhan, Stephen R. Koenning, and Greg L. TylkaInga A. ZasadaCorresponding author: Inga A. Zasada E-mail: E-mail Address: [email protected]Search for more papers by this author, Felicitas AvendanoSearch for more papers by this author, Yuncong C. LiSearch for more papers by this author, Terry LoganSearch for more papers by this author, Haddish MelakeberhanSearch for more papers by this author, Stephen R. KoenningSearch for more papers by this author, and Greg L. TylkaSearch for more papers by this authorAffiliationsAuthors and Affiliations Inga A. Zasada , USDA-ARS Nematology Laboratory, Beltsville, MD Felicitas Avendano , Iowa State University, Ames, IA Yuncong C. Li , University of Florida Tropical Research and Education Center, Homestead, FL Terry Logan , Logan Environmental Inc., Beaufort, SC Haddish Melakeberhan , Michigan State University, East Lansing, MI Stephen R. Koenning , North Carolina State University, Raleigh, NC Greg L. Tylka , Iowa State University, Ames, IA Published Online:11 Dec 2007https://doi.org/10.1094/PDIS-92-1-0004AboutSectionsPDF ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmailWechat DetailsFiguresLiterature CitedRelated Vol. 92, No. 1 January 2008SubscribeISSN:0191-2917e-ISSN:1943-7692 Metrics Article History Issue Date: 11 Dec 2007Published: 11 Dec 2007 Pages: 4-13 InformationThe American Phytopathological Society, 2008PDF downloadCited byThe Short-Term Effects of Amendments on Nematode Communities and Diversity Patterns under the Cultivation of Miscanthus × giganteus on Marginal Land29 August 2022 | Agronomy, Vol. 12, No. 9Nematodes as Ghosts of Land Use Past: Elucidating the Roles of Soil Nematode Community Studies as Indicators of Soil Health and Land Management Practices17 January 2022 | Applied Biochemistry and Biotechnology, Vol. 194, No. 5Effect of Soil Treatments and Amendments on the Nematode Community under Miscanthus Growing in a Lead Contaminated Military Site6 November 2020 | Agronomy, Vol. 10, No. 11Growth and Metal Uptake of Lettuce [ lactuca Sativa L] on Soil Amended with Biosolids and Gypsum5 August 2019 | Communications in Soil Science and Plant Analysis, Vol. 50, No. 16Growth and metal uptake of edamame [Glycine max (L.) Merr.] on soil amended with biosolids and gypsum9 November 2018 | Communications in Soil Science and Plant Analysis, Vol. 49, No. 22Effects of plant and animal waste-based compost amendments on the soil food web, soil properties, and yield and quality of fresh market and processing carrot cultivarsNematology, Vol. 20, No. 2Effects of agronomic practices on the timeline of Heterodera glycines establishment in a new locationNematology, Vol. 17, No. 6Effects of long-term organic amendments and soil sanitation on weed and nematode populations in pepper and watermelon crops in FloridaCrop Protection, Vol. 41Effects of organic amendment and tillage on soil microorganisms and microfaunaApplied Soil Ecology, Vol. 46, No. 1}, number={1}, journal={PLANT DISEASE}, author={Zasada, Inga A. and Avendano, Felicitas and Li, Yuncong C. and Logan, Terry and Melakeberhan, Haddish and Koenning, Stephen R. and Tylka, Greg L.}, year={2008}, month={Jan}, pages={4–13} }
 @article{koenning_edmisten_2008, title={Rotation with corn and soybean for management of Meloidogyne incognita in cotton}, volume={40}, number={4}, journal={Journal of Nematology}, author={Koenning, S. R. and Edmisten, K. L.}, year={2008}, pages={258–265} }
 @article{koenning_frye_butler_creswell_2007, title={First report of Phakopsora pachyrhizi on Kudzu (Pueraria montana var. lobata) in North Carolina and increased incidence of soybean rust on soybean in 2006.}, volume={91}, ISSN={["1943-7692"]}, DOI={10.1094/PDIS-91-5-0637A}, abstractNote={ Asian soybean rust, caused by Phakopsora pachyrhizi H. Sydow & Sydow, was first detected in the continental United States in soybean (Glycine max (L.) Merr.) in Louisiana on 6 November 2004 (3) and in kudzu (Pueraria montana var. lobata) in Florida during February 2005 (1). Soybean rust was first confirmed in North Carolina in commercial soybean fields in Brunswick, Columbus, and Robeson counties on 25 October 2005 (2). Subsequently, the disease was detected in soybean in 18 counties, but not in kudzu, even when it was growing adjacent to infected soybean. During 2006, soybean rust was first detected in North Carolina in soybean on 14 September 2006 from a sample from Columbus County that was submitted to the North Carolina State University Plant Disease and Insect Clinic (NCSU-PDIC). Thus, the first detection of soybean rust in North Carolina occurred almost 6 weeks earlier in 2006 than in 2005. Subsequently, in 2006, soybean rust was found in soybean in 42 counties in North Carolina through survey, sentinel plot monitoring, and samples submitted to the NCSU-PDIC. In addition, what appeared to be soybean rust was observed in two samples of kudzu collected on 3 and 6 November 2006 from Moore (35.28313°N, 79.38020°W) and Johnston (35.42742°N, 78.18154°W) counties of North Carolina. The diagnosis of P. pachyrhizi in kudzu was confirmed visually and by ELISA protocol supplied with the EnviroLogix QualiPlate kit (Portland, ME). ELISA tests for each kudzu sample were run in triplicate. PCR was also conducted on infected kudzu samples with a protocol previously reported (1). The PCR master mix that was used came from a dilution scheme based on previous PCR work completed by G. Z. Abad. A total of 24 reactions were run, including four 1-kb molecular markers, four positive controls, four negative controls, and four infected kudzu leaf tissue samples. The results of all diagnostic techniques confirmed the presence of P. pachyrhizi in diseased kudzu. To our knowledge, this is the first report of P. pachyrhizi in kudzu in North Carolina. }, number={5}, journal={PLANT DISEASE}, author={Koenning, S. R. and Frye, J. W. and Butler, S. C. and Creswell, T. C.}, year={2007}, month={May}, pages={637–637} }
 @article{koenning_frye_pataky_gibbs_cotton_2007, title={First report of Phoma terrestris causing red root rot on sweet corn (Zea mays) in North Carolina.}, volume={91}, ISSN={["0191-2917"]}, DOI={10.1094/PDIS-91-8-1054C}, abstractNote={ Red root rot, caused by Phoma terrestris E. M. Hansen, caused premature senescence and yield reductions to fresh-market sweet corn in Hyde County, North Carolina in July 2006. Foliar symptoms developed over a period of 5 to 8 days approximately 1 to 2 weeks after anthesis and included desiccation of leaves and poor development of ears. By 3 weeks after pollination, when the sweet corn was harvested, crowns and the first aboveground internode of affected plants were rotted and reddish colored, but roots appeared normal. The root mass of affected plants tended to be greater than that of unaffected plants. Incidence of symptomatic plants was greater than 30% in some fields and was lower on crops planted and harvested early. Symptomatic and asymptomatic plants were adjacent in affected fields. Diseased plants were more common in fields of sweet corn that followed soybean (Glycine max) or a double-crop of onions (Allium cepa) than in fields that followed corn. Incidence of symptomatic plants also differed among adjacent plantings of different sweet corn hybrids. Hybrids ‘173A’, ‘182A’, ‘378a’, and ‘XTH1178’ had a high incidence of symptomatic plants and ‘372A’, ‘278A’, ‘8101’, and ‘8102’ were less affected. Samples of symptomatic plants of the hybrid ‘182A’ were examined at the North Carolina Plant Disease and Insect Clinic during August. Olivaceous black pycnidia with long setae around the ostioles were imbedded in the stalk near the first node aboveground. Numerous conidia (1.8 to 2.3 × 4.5 to 5.5 μm) were released in cirri from pycnidia. When cultured on potato dextrose agar (PDA), the fungus produced a red pigment and intercalary and terminal chlamydospores. Pathogenicity was demonstrated in the greenhouse by transplanting corn seedlings or direct-seeding corn into pots of soil infested with plates of PDA containing chlamydospores and hyphae. A suspension of chlamydospores and hyphae also was injected into the stems of plants 28 days after transplanting. Five replicates of the pathogenicity experiments were repeated twice with noninoculated controls. After 8 weeks, P. terrestris was recovered from the roots of all inoculated plants. Soil inoculation resulted in necrotic root tissue in approximately 25% of inoculated plants. Approximately 90% of inoculated plants had discolored crowns that resembled symptoms from field infected plants. Stem inoculations resulted in necrosis extending 2 to 5 cm from the point of injection and resulted in shoot death of 40% of inoculated plants that resulted in the development of an adventitious shoot. Red root rot was prevalent on field corn in the Delmarva Peninsula throughout the late 1980s and 1990s (1). To our knowledge, this is the first report of this disease causing damage to sweet corn in North Carolina. Foliar symptoms and discoloration of crowns of diseased sweet corn plants were similar to previously described symptoms of red root rot on field corn (2), however, roots of affected sweet corn plants were not substantially rotted and did not have a symptomatic reddish pink or dark carmine color, presumably because sweet corn is harvested prior to the development of root symptoms. }, number={8}, journal={PLANT DISEASE}, author={Koenning, S. R. and Frye, J. W. and Pataky, J. K. and Gibbs, M. and Cotton, D.}, year={2007}, month={Aug}, pages={1054–1054} }
 @article{koenning_morrison_edmisten_2007, title={Relative efficacy of selected nematicides for management of Rotylenchulus reniformis in cotton}, volume={37}, number={2}, journal={Nematropica}, author={Koenning, S. R. and Morrison, D. E. and Edmisten, K. L.}, year={2007}, pages={227–235} }
 @article{starr_koenning_eirkpatrick_robinson_roberts_nichols_2007, title={The future of nematode management in cotton}, volume={39}, number={4}, journal={Journal of Nematology}, author={Starr, J. L. and Koenning, S. R. and Eirkpatrick, T. L. and Robinson, A. F. and Roberts, P. A. and Nichols, R. L.}, year={2007}, pages={283–294} }
 @article{wrather_koenning_2006, title={Estimates of disease effects on soybean yields in the United States 2003 to 2005}, volume={38}, number={2}, journal={Journal of Nematology}, author={Wrather, J. A. and Koenning, S. R.}, year={2006}, pages={173–180} }
 @article{koenning_moore_creswell_abad_palm_mckemy_hernandez_levy_devries-paterson_2006, title={First report of soybean rust caused by Phakopsora pachyrhizi in North Carolina.}, volume={90}, ISSN={["1943-7692"]}, DOI={10.1094/PD-90-0973A}, abstractNote={ Asian soybean rust, caused by Phakopsora pachyrhizi Sydow, has been known to occur in the eastern hemisphere for nearly a century. More recently, it was reported from South America in 2002 and the continental United States in Louisiana in November 2004 (1,2). Subsequently, P. pachyrhizi was confirmed in Alabama, Arkansas, Georgia, Florida, Missouri, Mississippi, South Carolina, and Tennessee in 2004. Surveys conducted in North Carolina in late November 2004 failed to detect this pathogen. Symptoms of the disease were first observed on soybean (Glycine max (L.) Merr.) in North Carolina on 25 October 2005 in farmers' fields in the counties of Brunswick, Columbus, and Robeson. Typical pustules and urediniospores were readily apparent on infected leaves when viewed with a dissecting microscope. Urediniospores were obovoid to broadly ellipsoidal, hyaline to pale yellowish brown with a minutely echinulate thin wall, and measured 18 to 37 × 15 to 24 μm. This morphology is typical of soybean rust caused by P. pachyrhizi or P. meibomiae, the latter is a less aggressive species causing soybean rust in the western hemisphere (1). DNA was extracted from leaves containing sori using the Qiagen DNeasy Plant Mini kit (Valencia, CA). P. pachyrhizi was detected using a real-time polymerase chain reaction (PCR) protocol that differentiates between P. pachyrhizi and P. meibomiae in a Cepheid thermocycler (Sunnyvale, CA) with appropriate positive and negative controls. The PCR master mix was modified to include OmniMix beads (Cepheid). Field diagnosis of P. pachyrhizi was confirmed by the USDA/APHIS on 28 October 2005. Soybean rust was identified in subsequent surveys of soybean fields and leaf samples submitted by North Carolina Cooperative Extension Agents in an additional 15 counties. These samples also were assayed using a traditional PCR protocol and by the enzyme-linked immunosorbent assay protocol included in the EnviroLogix QualiPlate kit (Portland, ME) for soybean rust. Ten soybean specimens from 10 sites were confirmed positive by these methods. Disease was not found on three kudzu samples, although one kudzu sample was adjacent to a soybean field that was positive for P. pachyrhizi. Although soybean rust was eventually detected in 18 North Carolina counties in 2005, no soybean yield loss occurred since the pathogen was detected when more than 80% of the soybean crop was mature. To our knowledge, this is the first report of P. pachyrhizi in North Carolina and the northern most find on soybean in the continental United States in 2005. }, number={7}, journal={PLANT DISEASE}, author={Koenning, S. R. and Moore, A. D. and Creswell, T. C. and Abad, G. Z. and Palm, M. E. and McKemy, J. M. and Hernandez, J. R. and Levy, L. and DeVries-Paterson, R.}, year={2006}, month={Jul}, pages={973–973} }
 @article{koenning_creswell_dunphy_sikora_mueller_2006, title={Increased occurrence of target spot of soybean caused by Corynespora cassiicola in the southeastern United States.}, volume={90}, ISSN={["0191-2917"]}, DOI={10.1094/PD-90-0974C}, abstractNote={ Target spot of soybean (Glycine max (L.) Merr.) caused by Corynespora cassiicola (Berk. & Curt.), although found in most soybean-growing countries, is considered to be a disease of limited importance (1) and has never been reported to cause soybean yield loss in the southeastern United States (2,3). Soybean plants submitted to the North Carolina Plant Disease and Insect Clinic (NCPDIC) in August 2004 from Beaufort, Robeson, Wilson, and Johnston counties, NC had symptoms consistent with target spot. Symptoms consisted of roughly circular, necrotic leaf lesions from minute to 11 mm in diameter, though typically approximately 4 to 5 mm in diameter, and with a yellow margin. Large lesions occasionally exhibited a zonate pattern often associated with this disease. Microscopic examination of the lesions revealed the presence of spores (conidia) typical of C. cassiicola (1). Conidia were mostly three to five septate with a central hilum at the base and ranged in size from 7 to 22 wide × 39 to 520 μm long. Three commercial soybean fields near Blackville, SC (Barnwell County) were severely affected by this disease and it caused premature defoliation. Nineteen of twenty-seven maturity group VII and VIII genotypes in the 2004 Clemson University soybean variety trial near Blackville, SC had visible symptoms of target spot. Heavy rainfall associated with hurricanes during September 2004 probably enhanced the incidence of this disease, and yield suppression due to target spot was estimated at 20 to 40% in some fields. In 2005, 20 of 161 soybean samples submitted to the NCPDIC or collected in surveys from 16 counties were positive for target spot on the basis of microscopic examination. Target spot also was diagnosed in six counties (Baldwin, DeKalb, Elmore, Fayette, Macon, and Pickens) in Alabama and in four additional counties (Bamberg, Hampton, Orange-burg, and Calhoun) in South Carolina in 2005. Records from the NCPDIC indicate that target spot had not been diagnosed on soybean in North Carolina since 1981. The large increase in incidence of target spot in the southeast may be related to changes in weather patterns, changes in pathogen virulence, and/or the introduction of more susceptible host genotypes. }, number={7}, journal={PLANT DISEASE}, author={Koenning, SR and Creswell, TC and Dunphy, EJ and Sikora, EJ and Mueller, JD}, year={2006}, month={Jul}, pages={974–974} }
 @article{koenning_bowman_morris_2006, title={Quantifying potential tolerance of selected cotton cultivars to Belonolaimus longicaudatus}, volume={38}, number={2}, journal={Journal of Nematology}, author={Koenning, S. R. and Bowman, D. T. and Morris, R. H.}, year={2006}, pages={187–191} }
 @article{koenning_bowman_2005, title={Cotton tolerance to Hoplolaimus columbus and impact on population densities}, volume={89}, ISSN={["1943-7692"]}, DOI={10.1094/PD-89-0649}, abstractNote={ Glyphosate-tolerant transgenic-cotton cultivars were evaluated for tolerance to Hoplolaimus columbus in field experiments conducted from 2001 to 2003. The studies were arranged in a split-plot design that included treatment with 1,3-dichloropropene at 42 liter/ha to establish fumigated versus nonfumigated subplots with cultivars as whole plots. Cotton cultivars were divided by relative maturity into two separate but adjacent experiments in order to facilitate cotton defoliation, with 10 early-maturity and 5 late-maturity cultivars. Fumigation was effective in suppressing H. columbus population densities and increased cotton lint yield. The cultivar-fumigation interaction was significant for early-season cotton cultivars but not for late-season cultivars. A tolerance index ([yield of nontreated/yield of treated] × 100) was used to compare cultivar differences. Both groups of cultivars expressed significant levels of tolerance to H. columbus, but late-season cultivars tended to yield more than early-season cultivars in infested fields. }, number={6}, journal={PLANT DISEASE}, author={Koenning, SR and Bowman, DT}, year={2005}, month={Jun}, pages={649–653} }
 @article{koenning_morrison_edmisten_taylor_2004, title={Efficacy of selected nematicides for management of Hoplolaimus columbus in cotton.}, volume={34}, number={2}, journal={Nematropica}, author={Koenning, S. R. and Morrison, D. E. and Edmisten, K. L. and Taylor, R. N.}, year={2004}, pages={211–218} }
 @article{koenning_barker_2004, title={Influence of poultry litter applications on nematode communities in cotton agroecosystems}, volume={36}, number={4}, journal={Journal of Nematology}, author={Koenning, S. R. and Barker, K. R.}, year={2004}, pages={524–533} }
 @misc{koenning_kirkpatrick_starr_wrather_walker_mueller_2004, title={Plant-parasitic nematodes attacking cotton in the United States - Old and emerging production challenges}, volume={88}, ISSN={["1943-7692"]}, DOI={10.1094/PDIS.2004.88.2.100}, abstractNote={Cotton is the most important fiber crop in the world, and current U.S. lint production accounts for nearly one quarter of the world supply. The unique role of cotton in world and American history is profound. Primitive cottons have been used in Africa, Asia, and the Americas for millennia. Domestic and international demand for cotton fiber contributed greatly to the westward expansion of the United States, the American Civil War, and the industrial revolution (81). The land area devoted to cotton production in the United States peaked in 1926 with approximately 18 million hectares (Fig. 1). The advent of mechanized farming equipment and the availability of effective, relatively low-cost fertilizers, pesticides, and improved cotton cultivars after World War II allowed the production of significantly greater yields per unit of land area, and hectarage declined. U.S. production of cotton lint in the past 5 years has varied from 3.0 × 10 to 4.4 × 10 kg produced on about 5 million hectares (147). Additionally, cotton seed is a valuable source of vegetable oil and protein used in animal feed, with production of 4.9 × 10 to 5.9 × 10 kg of cotton seed annually. Since World War II, cotton cultivation was increasingly dependent on inputs of chemical pesticides for weed and insect control. Historically, the cotton boll weevil, Anthonomus grandis Boheman, was the most costly pest of cotton in the United States. The combination of crop loss due to this insect directly and the expense for insecticides that was incurred by cotton growers attempting to control it amounted to several billion dollars annually until recently (130). The successful establishment of the Boll Weevil Eradication Program coordinated by the U.S. Department of Agriculture in many states in the eastern half of the country has resulted in a reduction in insecticide usage, improved profitability for growers, and has led to a resurgence of cotton production in the Southeast (37). In addition, the current widespread use of transgenic cotton cultivars with resistance to herbicides and/or insects also has greatly reduced the need for inputs of pesticides. Currently, 71% of cotton grown in the United States is herbicide resistant, resistant to lepidopteran insects, or has resistance to both (3). Reductions in pest pressure from weeds and insects as a result of the deployment of transgenic resistance and the boll weevil eradication program have}, number={2}, journal={PLANT DISEASE}, author={Koenning, SR and Kirkpatrick, TL and Starr, JL and Wrather, JA and Walker, NR and Mueller, JD}, year={2004}, month={Feb}, pages={100–113} }
 @inbook{koenning_2004, title={Population biology}, booktitle={Biology and management of the soybean cyst nematode  (2nd ed.)}, publisher={Weinheim: Wiley-VCH}, author={Koenning, S. R.}, editor={R. D. Riggs and Wrather, J. A.Editors}, year={2004}, pages={73–88} }
 @inbook{schmitt_koenning_barker_2004, title={Population density based management}, booktitle={Biology and management of the soybean cyst nematode  (2nd ed.)}, publisher={Weinheim: Wiley-VCH}, author={Schmitt, D. P. and Koenning, S. R. and Barker, K. R.}, editor={R. D. Riggs and Wrather, J. A.Editors}, year={2004}, pages={89–110} }
 @article{koenning_2004, title={Resistance of soybean cultivars to field populations of Heterodera glycines in North Carolina}, volume={88}, ISSN={["1943-7692"]}, DOI={10.1094/PDIS.2004.88.9.942}, abstractNote={ The soybean cyst nematode (SCN), Heterodera glycines, is the most important pathogen of soybean, Glycine max, in North Carolina. Cultural practices are the most effective means of managing this pathogen because a majority of cultivars are susceptible to the races of this nematode that predominate in the state. Resistant and susceptible cultivars were evaluated in 14 H. glycines-infested fields from 1992 to 1999. Resistance in cvs. Hartwig and Delsoy 5710, and line S92-1603 derived from plant introduction (PI) 437654, was highly effective against all populations of H. glycines evaluated in these experiments. Numbers of cysts (cysts and white females) per three plants 28 days after planting and final egg population densities (Pf) were lower than on other cultivars evaluated. Cultivars with SCN resistance derived from PI 90763 were moderately resistant in many of the test fields, but cultivars with Peking-derived resistance were effective at only two locations. Some cultivars with resistance derived from PI 88788 were highly to moderately resistant to races 9 or 14 of SCN, but were not consistently effective against other populations. Hartwig and Delsoy 5710 had low SCN reproductive factors (Rf = egg density at harvest/mean egg density at planting for site) of 0.16 and 0.23 compared with an Rf of 1.9 and 2.19 on the susceptible cvs. Essex and Hutcheson, respectively. In contrast, the Rf on cultivars derived from Peking generally was greater than on susceptible cultivars. Resistant cvs. Hartwig and Delsoy 5710 generally yielded more than susceptible cultivars or cultivars derived from other sources of resistance. The initial inoculum level (Pi) was negatively correlated with soybean seed yield, but cysts 28 days after planting proved to be better at predicting seed yield than Pi. Due to the genetic diversity of H. glycines populations with regard to the ability to parasitize resistant cultivars, cultivars with resistance derived from PI 437654 or other genotypes are needed to manage this nematode in North Carolina. }, number={9}, journal={PLANT DISEASE}, author={Koenning, SR}, year={2004}, month={Sep}, pages={942–950} }
 @article{wrather_koenning_anderson_2003, title={Effect of diseases on soybean yields in the United States and Ontario 1992-2002}, DOI={10.1094/php-2003-0325-01-rv}, abstractNote={ Soybean yields in the U.S. and Ontario have often been suppressed by diseases. The resulting losses are important to rural economies and to the economies of allied industries in urban areas. The authors compiled estimates of soybean yield losses due to diseases for each soybean producing state in the U.S. and Ontario from 1999 to 2002. The goal was to provide this information to help funding agencies and scientists prioritize research objectives and budgets. }, number={2003 March 25}, journal={Plant Health Progress}, author={Wrather, J. A. and Koenning, S. R. and Anderson, T.}, year={2003} }
 @article{koenning_edmisten_barker_bowman_morrison_2003, title={Effects of rate and time of application of poultry litter on Hoplolaimus columbus on cotton}, volume={87}, ISSN={["0191-2917"]}, DOI={10.1094/PDIS.2003.87.10.1244}, abstractNote={ Field experiments were conducted to evaluate the effect of soil-incorporated poultry litter on the population dynamics of Hoplolaimus columbus and cotton lint yield. Rates of poultry litter applied varied from 0.0 to 27.0 t/ha and were applied in December, February, or March. Time of application did not influence population densities of this nematode or cotton yield. The rate of poultry litter applied was negatively related to the population density of H. columbus at midseason, but not at other sampling dates. The lower midseason levels of this nematode corresponded with increases in cotton lint yield in all experiments. Cotton yield increases generally were linear with respect to the rate of litter applied, although the highest rates of litter applied did not always result in the greatest cotton yield. Poultry litter can be used effectively to supply nutrients to the crop and suppress damaging levels of H. columbus. Optimal rates of litter application were from 6.0 to 13.4 t/ha. Application of poultry litter at these rates, however, may exceed nutrient levels required for best management practices. }, number={10}, journal={PLANT DISEASE}, author={Koenning, SR and Edmisten, KL and Barker, KR and Bowman, DT and Morrison, DE}, year={2003}, month={Oct}, pages={1244–1249} }
 @article{koenning_edmisten_barker_morrison_2003, title={Impact of cotton production systems on management of Hoplolaimus columbus}, volume={35}, number={1}, journal={Journal of Nematology}, author={Koenning, S. R. and Edmisten, K. L. and Barker, K. R. and Morrison, D. E.}, year={2003}, pages={73–77} }
 @article{tu_koenning_hu_2003, title={Root-parasitic nematodes enhance soil microbial activities and nitrogen mineralization}, volume={46}, ISSN={["1432-184X"]}, DOI={10.1007/s00248-002-1068-2}, abstractNote={Obligate root-parasitic nematodes can affect soil microbes positively by enhancing C and nutrient leakage from roots but negatively by restricting total root growth. However, it is unclear how the resulting changes in C availability affect soil microbial activities and N cycling. In a microplot experiment, effects of root-parasitic reniform nematodes ( Rotylenchulus reniformis) on soil microbial biomass and activities were examined in six different soils planted with cotton. Rotylenchulus reniformis was introduced at 900 nematodes kg(-1) soil in May 2000 prior to seeding cotton. In 2001, soil samples were collected in May before cotton was seeded and in November at the final harvest. Extractable C and N were consistently higher in the R. reniformis treatments than in the non-nematode controls across the six different soils. Nematode inoculation significantly reduced microbial biomass C, but increased microbial biomass N, leading to marked decreases in microbial biomass C:N ratios. Soil microbial respiration and net N mineralization rates were also consistently higher in the nematode treatments than in the controls. However, soil types did not have a significant impact on the effects of nematodes on these microbial parameters. These findings indicate that nematode infection of plant roots may enhance microbial activities and the turnover of soil microbial biomass, facilitating soil N cycling. The present study provides the first evidence about the direct role of root-feeding nematodes in enhancing soil N mineralization.}, number={1}, journal={MICROBIAL ECOLOGY}, author={Tu, C and Koenning, SR and Hu, S}, year={2003}, month={Jul}, pages={134–144} }
 @article{davis_koenning_kemerait_cummings_shurley_2003, title={Rotylenchulus reniformis management in cotton with crop rotation}, volume={35}, number={1}, journal={Journal of Nematology}, author={Davis, R. F. and Koenning, S. R. and Kemerait, R. C. and Cummings, T. D. and Shurley, W. D.}, year={2003}, pages={58–64} }
 @article{koenning_2002, title={Nematicides}, DOI={10.1201/noe0824706326.ch233}, number={2002}, journal={Encyclopedia of pest management}, publisher={New York: Marcell Dekker}, author={Koenning, S. R.}, year={2002} }
 @article{koenning_2002, title={Tolerance to Hoplolaimus columbus in glyphosate-resistant, transgenic soybean cultivars}, volume={34}, number={4}, journal={Journal of Nematology}, author={Koenning, S. R.}, year={2002}, pages={370–373} }
 @article{hillocks_koenning_2001, title={Other stem and root diseases}, journal={Compendium of cotton diseases  (2nd ed)}, publisher={St. Paul, Minn.: American Phytopathological Society}, author={Hillocks, R. J. and Koenning, S. R.}, editor={T. L. Kirkpatrick and Rothrock, C. S.Editors}, year={2001}, pages={33} }
 @article{koenning_barker_bowman_2001, title={Resistance as a tactic for management of Meloidogyne incognita on cotton in North Carolina}, volume={33}, number={2-3}, journal={Journal of Nematology}, author={Koenning, S. R. and Barker, K. R. and Bowman, D. T.}, year={2001}, pages={126–131} }
 @article{wrather_stienstra_koenning_2001, title={Soybean disease loss estimates for the United States from 1996 to 1998}, volume={23}, ISSN={["0706-0661"]}, DOI={10.1080/07060660109506919}, abstractNote={Soybean disease loss estimates were compiled for the 1996 to 1998 harvested crops from all soybean-producing states in the United States. Scientists from each state provided estimates of losses based on field surveys, information from field workers and university extension staff, and research plot data. Total yield losses caused by soybean cyst [Heterodera glycines Ichinohe] in the United States were greater than those caused by any other disease. Next in importance were phytophthora root and stem rot [Phytophthora sojae (Kaufman & Gerdemann)], brown stem rot [Phialophora gregata (Allington & Chamberlain) Gams], sclerotinia stem rot [Sclerotinia sclerotiorum (Lib.) de Bary], and seedling diseases. Yield loss estimates due to particular diseases varied by region and among years. The estimated soybean yield losses to diseases in the United States were 10.9 × 106 t in 1996, 11.9 × 106 t in 1997, and 14.0 × 106 t in 1998.}, number={2}, journal={CANADIAN JOURNAL OF PLANT PATHOLOGY-REVUE CANADIENNE DE PHYTOPATHOLOGIE}, author={Wrather, JA and Stienstra, WC and Koenning, SR}, year={2001}, month={Jun}, pages={122–131} }
 @article{koenning_2000, title={Density-dependent yield of Heterodera glycines-resistant and -susceptible cultivars}, volume={32}, number={4}, journal={Journal of Nematology}, author={Koenning, S. R.}, year={2000}, pages={502–507} }
 @article{koenning_abdel alim_grand_2000, title={Stem canker of cotton caused by Phoma exigua in North Carolina}, volume={84}, number={2000}, journal={Plant Disease}, author={Koenning, S. R. and Abdel Alim, F. F. and Grand, L. F.}, year={2000}, pages={1251} }
 @article{koenning_barker_bowman_2000, title={Tolerance of selected cotton lines to Rotylenchulus reniformis}, volume={32}, number={4}, journal={Journal of Nematology}, author={Koenning, S. R. and Barker, K. R. and Bowman, D. T.}, year={2000}, pages={519–523} }
 @article{koenning_overstreet_noling_donald_becker_fortnum_1999, title={Survey of crop losses in response to phytoparasitic nematodes in the United States for 1994}, volume={31}, number={4}, journal={Journal of Nematology}, author={Koenning, S. R. and Overstreet, C. and Noling, J. W. and Donald, P. A. and Becker, J. O. and Fortnum, B. A.}, year={1999}, pages={587–618} }
 @inbook{koenning_sipes_1998, title={Biology}, DOI={10.1007/978-94-015-9018-1_7}, booktitle={The cyst nematodes}, publisher={Dordrecht ; Boston: Kluwer Academic Publishers}, author={Koenning, S. R. and Sipes, B. S.}, year={1998}, pages={156–190} }
 @misc{barker_koenning_1998, title={Developing sustainable systems for nematode management}, volume={36}, ISSN={["1545-2107"]}, DOI={10.1146/annurev.phyto.36.1.165}, abstractNote={ ▪ Abstract  Early researchers identified key concepts and developed tactics for multiple-option management of nematodes. Although the emphasis on integrated pest management over the past three decades has promoted strategies and tactics for nematode management, comprehensive studies on the related soil biology–ecology are relatively recent. Traditional management tactics include host resistance (where available), cultural tactics such as rotation with nonhosts, sanitation and avoidance, and destruction of residual crop roots, and the judicious use of nematicides. There have been advances in biological control of nematodes, but field-scale exploitation of this tactic remains to be realized. New technologies and resources are currently becoming central to the development of sustainable systems for nematode-pest-crop management: molecular diagnostics for nematode identification, genetic engineering for host resistance, and the elucidation and application of soil biology for general integrated cropping systems. The latter strategy includes the use of nematode-pest antagonistic cover crops, animal wastes, and limited tillage practices that favor growth-promoting rhizobacteria, earthworms, predatory mites, and other beneficial organisms while suppressing parasitic nematodes and other plant pathogens. Certain rhizobacteria may induce systemic host resistance to nematodes and, in some instances, to foliage pathogens. The systems focusing on soil biology hold great promise for sustainable crop-nematode management, but only a few research programs are currently involved in this labor-intensive endeavor. }, journal={ANNUAL REVIEW OF PHYTOPATHOLOGY}, author={Barker, KR and Koenning, SR}, year={1998}, pages={165–205} }
 @article{koenning_coble_bradley_barker_schmitt_1998, title={Effects of a low rate, of aldicarb on soybean and associated pest interactions in fields infested with Heterodera glycines}, volume={28}, number={2}, journal={Nematropica}, author={Koenning, S. R. and Coble, H. D. and Bradley, J. R. and Barker, K. R. and Schmitt, D. P.}, year={1998}, pages={205–211} }
 @article{koenning_bailey_schmitt_barker_1998, title={Management of plant-parastic nematodes on peanut with selected nematicides in North Carolina}, volume={30}, number={4 suppl.}, journal={Journal of Nematology}, author={Koenning, S. R. and Bailey, J. E. and Schmitt, D. P. and Barker, K. R.}, year={1998}, pages={643–650} }
 @article{koenning_barker_1998, title={Survey of Heterodera glycines races and other plant-parastic nematodes on soybean in North Carolina}, volume={30}, number={4, Suppl.}, journal={Journal of Nematology}, author={Koenning, S. R. and Barker, K. R.}, year={1998}, pages={569–576} }
 @article{koenning_walters_barker_1996, title={Impact of soil texture on the reproductive and damage potentials of Rotylenchulus reniformis and Meloidogyne incognita on cotton}, volume={28}, number={4}, journal={Journal of Nematology}, author={Koenning, S. R. and Walters, S. A. and Barker, K. R.}, year={1996}, pages={527} }
 @article{koenning_schmitt_barker_1996, title={Soybean maturity group and planting date effects on seed yield and population densities of Heterodera glycines}, volume={19}, number={2}, journal={Fundamental and Applied Nematology}, author={Koenning, S. R. and Schmitt, D. P. and Barker, K. R.}, year={1996}, pages={135} }
 @article{koenning_schmitt_barker_gumpertz_1995, title={IMPACT OF CROP-ROTATION AND TILLAGE SYSTEM ON HETERODERA-GLYCINES POPULATION-DENSITY AND SOYBEAN YIELD}, volume={79}, ISSN={["1943-7692"]}, DOI={10.1094/PD-79-0282}, abstractNote={The long-term effects of no-till planting practices and rotation on the population dynamics of the soybean cyst nematode (Heterodera glycines) and soybean yield were investigated in field experiments over a period of 8 yr. The experiment was a 2 X 4 factorial, comparing no-till vs. conventional tillage practices in four cropping patterns (continuous soybean, a 1-yr rotation of corn and soybean, a rotation of 2 yr of corn followed by soybean, and a corn-wheat/soybean double-cropping system). Treatments were arranged so that each combination occurred every year after 1986. Soybean after 1 yr of corn had higher yields (P = 0.0001) than soybean after soybean. Two years of corn between soybean crops resulted in soybean yields higher than those after 1 yr of corn in only 2 out of 6 yr. The yields of soybean in the corn, wheat/soybean double-cropping system, however, were generally similar to monoculture soybean. No-till practices had positive or no effects on soybean yield early in the study, but yields of no-till soybean were lower (P = 0.01) than conventionally tilled soybean after several years because weed pressure was greater in no-till plots. Population densities of H. glycines were greater (P < 0.10) in conventionally tilled plots than in no-till plots in 1988 and 1990-1992. Numbers of H. glycines fluctuated in an unpredictable manner from year to year, possibly because of unidentified biological control agents or excessive moisture in certain years. H. glycines population densities declined in a predictable manner when a nonhost was planted}, number={3}, journal={PLANT DISEASE}, author={KOENNING, SR and SCHMITT, DP and BARKER, KR and GUMPERTZ, ML}, year={1995}, month={Mar}, pages={282–286} }
 @article{koenning_barker_1995, title={Soybean photosynthesis and yield as influenced by Heterodera glycines, soil type and irrigation}, volume={27}, number={1}, journal={Journal of Nematology}, author={Koenning, S. R. and Barker, K. R.}, year={1995}, pages={51} }
 @article{koenning_schmitt_barker_1993, title={EFFECTS OF CROPPING SYSTEMS ON POPULATION-DENSITY OF HETERODERA-GLYCINES AND SOYBEAN YIELD}, volume={77}, ISSN={["0191-2917"]}, DOI={10.1094/PD-77-0780}, abstractNote={We evaluated the effects of soybean planting date and maturity group (MG) on final population density of Heterodera glycines and yield in cultivars susceptible to H, glycines grown in monoculture and in rotations with 1 or 2 yr of nonhosts. Population density of eggs and eggs plus second-stage juveniles of H. glycines declined to barely detectable levels after 2 yr of nonhost culture. Population densities of this nematode were consistently greater (P=0.05) for an MG VII cultivar than an MG V cultivar. Planting date had variable effects on final population density of H. glycines: early planting resulted in the highest nematode numbers in some years, whereas late planting was associated with significantly greater (P=0.05) population densities in other years}, number={8}, journal={PLANT DISEASE}, author={KOENNING, SR and SCHMITT, DP and BARKER, KR}, year={1993}, month={Aug}, pages={780–786} }
 @article{koenning_barker_1992, title={A novel technique for infesting field sites with encapsulated eggs of Meloidogyne spp}, volume={24}, number={1}, journal={Journal of Nematology}, author={Koenning, S. R. and Barker, K. R.}, year={1992}, pages={183} }
 @article{koenning_barker_1992, title={Field evaluation of selected soybean cultivars for resistance to two races of Meloidogyne arenaria}, volume={24}, number={4}, journal={Journal of Nematology}, author={Koenning, S. R. and Barker, K. R.}, year={1992}, pages={735} }
 @article{koenning_barker_1992, title={Relative damage function and reproductive potentials of Meloidogyne arenaria and M. hapla on peanut}, volume={24}, number={1}, journal={Journal of Nematology}, author={Koenning, S. R. and Barker, K. R.}, year={1992}, pages={187} }