Impacts of Row Spacing and Fungicide Timing on Foliar Disease, Greenstem, and Yield in Double-Cropped Soybeans Grown in the Chesapeake Bay Region of the United States

Abstract

Double cropped soybeans are planted on approximately 1/3 of crop acres in the Chesapeake Bay region of the United States. Producers have asked if foliar fungicides are required to optimize yields in this region. We assessed the impacts of foliar fungicide application timing and row spacing on foliar disease, greenstem, and yield from 11 site years spanning 2017-2019. Foliar diseases only developed at rateable levels in one location. Fungicide application, regardless of timing, increased percent greenstem over non-treated controls. Fungicide application did not impact soybean yield. Yield was greater in 38.1 cm rows when compared to 19 cm rows. Our data do not support the use of foliar fungicides in double cropped soybean production in this region.