Method and Timing of Rye Control Affects Soybean Development and Resource Utilization

Abstract

Cover crops provide environmental and soil quality benefits, yet their adoption into production agriculture has been limited. This study was conducted to determine the influence of the growth stage and method of rye (Secale cereale L.) control on soybean [Glycine max (L.) Merr.] development and resource utilization. Fall‐planted rye was controlled the following spring using a stalk chopper (mechanical) or glyphosate (chemical) at the second‐node, boot, and anthesis growth stages near Boone, IA, in 2002 and 2003. Regrowth from mechanical rye control in 2002 depleted soil water until rye matured. Maximum light interception by soybean was reduced by as much as 43 and 30% in chemical and 51 and 23% in mechanical control compared with the no‐rye check in 2002 and 2003. Dry matter (DM) accumulation was reduced by as much as 267 and 907 g m−2 in chemical and mechanical control in 2002 compared with the check. In 2003, the range in DM accumulation was 242 g m−2. Rye delayed pod maturity in both years by as much as 7.9 d. Producers who adopt these methods of rye management can expect delayed soybean maturity and reduced DM accumulation.