Influence of planting date, maturity group, and harvest timing on soybean yield and seed quality

Abstract

As in other soybean-producing regions in the United States, planting date and maturity group (MG) are two of the most important factors, along with variety selection and timely harvest, that can set the stage to optimize soybean yield potential in Louisiana. Limited data are available on the effect of these factors along with harvest timing on soybean seed quality. Field studies evaluated the influence of planting date, MG, and harvest timing on soybean yield and seed quality at the Louisiana State University AgCenter Northeast, Macon Ridge, and Dean Lee Research Stations in 2018–2020. Soybean yield was optimized when MG 4 and 5 soybean varieties were planted between mid-April and mid-May. Earlier and later planting dates did not result in maximum yield. Planting date effects on seed quality, however, were negligible. Greatest soybean quality was obtained when planting relative maturities (RM) 5.4–6.0 soybean; however, as indicated in the planting date study, yield was not maximized. Planting RM 3.0–4.4 soybean varieties in Louisiana resulted in lower seed quality. Soybean varieties within RM 4.5–5.3 resulted in acceptable seed quality and maximum yield in Louisiana, assuming plants are harvested at the optimum harvest timing (when seed reaches 13% moisture) and not delayed 14–28 days.