Herbicides selectivity and efficacy to caupi bean crop

Abstract

Caupi bean is grow by small farmer’s family using low technological level, where weeds management is conducted by hoeing, and an exhausted practice with low efficiency action. The objective of this study was to evaluate herbicides selectivity and control weeds efficacy in caupi crop, BRS Guariba cultivar. The experiment was conducted in field conditions with the application of herbicides (g a.e. ha^-1) sulfentrazone (500) e oxadiazon (600), in pre emergence conditions, and bentazon (600), bentazon + paraquat (39 + 62), fomesafen (225), fluazifop-p-butyl (250) and fomesafen + fluazifop-p-butyl (125 + 125), in post emergence, one treatment with hoeing at 20 and 34 days after crop emergence and a check without hoeing during the whole crop cycle. Bentazon + paraquat application promoted high phytotoxicity in caupi bean, and oxadiazon, sulfentrazone, bentazon and fluazifop-p-butyl guaranteed an excellent control of weeds, with yields really similar to those obtained with two  hoeing.  Fomesafen associated or not to fluazifop-p-butyl caused moderate phytotoxicity, delays flowering and harvest, besides crop yield reduction. Weeds interference during the whole crop cycle reduced grains yield in 42%.