Response of dry bean to pre-plant incorporated and pre-emergence applications of S-metolachlor and fomesafen

There is limited information on the tolerance of various market classes of dry bean to the soil application of fomesafen alone or in tank mix combination with S-metolachlor. Field trials were conducted in Ontario over a two year period (2006 and 2007) to evaluate the tolerance of black, cranberry, kidney, and white (navy) bean to the pre-plant incorporated (PPI) and pre-emergence (PRE) application of S-metolachlor and fomesafen alone and in tank mix combination. Treatments included a non-treated check. All treatments were maintained weed free during the growing season. Visible injury differed among the four market classes of dry bean at 14 days after emergence. Visible injury was generally greater in the smaller seed market classes (black and white bean) compared to the larger seeded market classes (kidney and cranberry bean). Visible injury seen in some market classes of dry bean early in the season was minimal and transitory and caused no adverse effects on plant height, shoot dry weight, seed moisture content, and yield. Based on these results, S-metolachlor and fomesafen alone and in combination applied PPI or PRE at the proposed maximum use dose can be safely used for weed management in black, cranberry, kidney, and white bean production in Ontario.