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ARS Home » Southeast Area » Stoneville, Mississippi » Southern Insect Management Research » Research » Publications at this Location » Publication #396479
Research Project: Insect Control and Resistance Management in Corn, Cotton, Sorghum, Soybean, and Sweet Potato, and Alternative Approaches to Tarnished Plant Bug Control in the Southern United States

Location: Southern Insect Management Research

Title: Effects of soybean planting date on yield loss from defoliation

Author
item THRASH, BENJAMIN - University Of Arkansas
item CATCHOT, ANGUS - Mississippi State University
item GORE, JEFF - Mississippi State University
item COOK, DONALD - Mississippi State University
item MUSSER, FRED - Mississippi State University
item IRBY, TRENTON - Mississippi State University
item KRUTZ, JASON - Mississippi State University
item LORENZ, GUS III - University Of Arkansas

Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/9/2020
Publication Date: 1/18/2021
Citation: Thrash, B.C., Catchot, A.L., Gore, J., Cook, D.R., Musser, F.R., Irby, T., Krutz, J., Lorenz, G.M. 2021. Effects of soybean planting date on yield loss from defoliation. Journal of Economic Entomology. 114(2):993-997. https://doi.org/10.1093/jee/toaa280.
DOI: https://doi.org/10.1093/jee/toaa280

Interpretive Summary: Historically, the recommended planting dates for soybean in the Mid-South region of the United States began in May and continued into June, with the dominant cultivars being maturity groups V, VI, and VII. Currently, no information exists regarding the effects of planting date on soybean yield loss from early season defoliation. In 2015 and 2016, to evaluate the effects of planting date on yield loss from defoliation,soybean were planted in field plots 2 weeks apart from early April to mid-June, for a total of six planting dates. Each planting date included a nondefoliated control and a 100% defoliation treatment where leaves were manually excised before bloom when plants had four fully developed trifoliate leaf nodes. Mean yield loss from defoliation varied across planting dates, with mid-April plantings having the least amount yield reduction, 573 kg/ha, and early-June plantings having the greatest yield reduction, 904 kg/ha. Percent yield reduction from defoliation increased as planting was delayed, suggesting that defoliation thresholds might need adjustment based on planting date and yield potential. However, more research is needed at lower levels of defoliation to accurately delineate such thresholds.

Technical Abstract: Soybean, Glycine max (L.) Merr., is planted during 3.5–4 mo across the Mid-South United States. Currently, no information exists regarding the effects of planting date on soybean yield loss from early season defoliation. In 2015 and 2016, to evaluate the effects of planting date on yield loss from defoliation, soybean were planted in field plots 2 wk apart from early April to mid-June, for a total of six planting dates. Each planting date included a nondefoliated control and a 100% defoliation treatment where leaves were manually excised at the V4 growth stage. Mean yield loss from defoliation varied across planting dates, with mid-April plantings having the least amount yield reduction, 573 kg/ha, and early-June plantings having the greatest yield reduction, 904 kg/ha. Percent yield reduction from defoliation increased as planting was delayed, suggesting that defoliation thresholds might need adjustment based on planting date and yield potential. However, more research is needed at lower levels of defoliation to accurately delineate such thresholds.