Herbicide association applied to control weeds in bean of black type

Abstract

Black bean is one of the main grains grown in Brazil, with economic, social and cultural importance. Grain productivity losses due to competition with weeds, in particular Digitaria ciliaris (summergrass) and Urochloa plantaginea (signalgrass) can reach levels of up to 80% if neither Control is adopted. The objective of this study was to evaluate the efficacy and selectivity of herbicides applied in pre and post emergence of black beans. The experimental design was a randomized block design, with four replications. The herbicides used were fomesafen (250 g ha-1 a.i), s-metolachlor (1200 g ha-1), oxyfluorfen (480 g ha-1 of a.i), clomazone (1000 g ha-1 of a.i), pendimentalin (250 g ha-1 of a.i), imazamox (42 g ha-1 of a.i), bentazon (720 g ha-1 of a.i), bentazon + imazamox (600 + 28 g ha-1 of a.i), flumioxazin (25 g ha-1 of a.i), fluazifop-p-buthyl + fomesafen (250 +250 g ha-1 of a.i), followed by two additional controls, one weed and one infested. O oxyfluorfen presented the highest levels of phytotoxicity to BRS Campeiro bean, which resulted in a negative effect on components of grain yield, together with the infested control, s-metolachlor, pendimentalin, flumioxazin, fomesafen and bentazon. The commercial mixture of bentazon + imazamox presented low phytotoxicity, the best results of the components of grain yield, together with a good control of the summergrass and the signalgrass.