This work has assessed the efficiency of herbicides in bean crop and their potential residual effect on succeeding sorghum or maize culture. The experiment was conducted under field and greenhouse conditions, and the following treatments were assessed: fomesafen (250 g L-1) and mix of bentazon and imazamox (600 g L-1 + 28 g L-1) at doses of 0.25, 0.50, 0.75 and 1.0 times the recommended dose of the respective commercial products, plus the tank mix of these herbicides in proportions of 0.75 + 0.25, 0.50 + 0.50, and 0.25 + 0.75, and two controls: a weeded one and one without weeding. The 250 g ha-1 dose of fomesafen provided good bean yield, however it hindered the growth of sorghum in soil samples collected at 183 days after application, suggesting large persistence of this herbicide in soil. Intoxication in maize plants was observed in soil collected at 153 DAA, but there was no influence on shoot dry matter accumulation or in grain yield. The bentazon and imazamox mix was effective in controlling weeds up until the harvest of beans. However, when fomesafen was added to this mixture, its dose was reduced in ¼, and the mix provided great weed control and easy harvest conditions for the bean, in addition to lower carryover risk for sorghum and maize plants. The persistence of fomesafen in soil has not changed with the tank mixture of bentazon and imazamox.
persistence in soil; carryover; selectivity
