Weed Control in White Bean with Pendimethalin Applied Preplant Followed by Postemergence Broadleaved Herbicides

Field trials were conducted over a three-year period (2009 to 2011) to evaluate the efficacy of pendimethalin preplant-incorporated (PPI), bentazon, fomesafen, bentazon plus fomesafen, or halosulfuron applied postemergence (POST) and the sequential application of pendimethalin applied PPI followed by bentazon, fomesafen, bentazon plus fomesafen or halosulfuron applied POST in white bean in Ontario. There was minimal effect on seed moisture content of white bean with the herbicides evaluated. Pendimethalin provided 97% control of A. retroflexus, 9% of A. artemisiifolia, 90% of C. album, 12% of S. arvensis, and 96% of S.viridis. Bentazon, fomesafen, bentazon plus fomesafen, and halosulfuron applied POST provided as much as 93% control of A. retroflexus, 86% control of A. artemisiifolia, 72% control of C. album, 99% control of S. arvensis, and 29% control of S. viridis. The sequential application of pendimethalin applied PPI followed by bentazon, fomesafen, bentazon plus fomesafen, and halosulfuron applied POST provided 100% control of A. retroflexus, 87% control of A. artemisiifolia, 90% control of C. album, 100% control of S. arvensis, and 95% control of S .viridis, respectively. White bean yield generally reflected the level of weed control.