Control of volunteer adzuki bean (Vigna angularis) with pre- and postemergence herbicides in corn (Zea mays)

Abstract

Volunteer adzuki bean within a corn crop can decrease corn yield and increase the adzuki bean seed bank. The objective of this research was to evaluate the efficacy of various preemergence (PRE) and postemergence (POST) herbicides for the control of volunteer adzuki bean [Vigna angularis (Willd.) Ohwi & Ohashi] in corn. Trials were conducted at two locations in 2005, 2006, 2007 and 2009. Experiments were arranged in a randomized complete block design with either seven PRE or ten POST herbicides. Volunteer adzuki bean interference resulted in corn yield losses of 16 to 43%. The PRE herbicides provided variable control. The highest and most consistent control PRE was provided by dicamba/atrazine, which provided 69 to 97% control of volunteer adzuki bean at 4 and 8 wk after emergence (WAE), respectively. Dicamba/atrazine PRE reduced volunteer adzuki bean density and biomass 67 to 97% 10 WAE. Generally, the POST herbicides evaluated provided better and more consistent control of volunteer adzuki bean than the PRE herbicides. Dicamba/atrazine applied POST provided greater than 95% control of volunteer adzuki bean and consistently reduced volunteer adzuki bean density and biomass to the equivalent of the weed-free control. Dicamba/atrazine applied POST resulted in corn yields equivalent to the weed-free control. The best option for controlling volunteer adzuki bean in corn is to apply dicamba/atrazine POST, while the remaining herbicides evaluated provided variable control.