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 fo- mesafen 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 halosul- furon 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.