Application of herbicides and sugar cane straw on controlling of Mucuna aterrima L. in peanut crop

Abstract

Peanut crop is normally cultivated in sugar cane renewal areas in Brazil, where velvet bean (Mucuna aterrima) is a troublesome weed, in which the control is essential. The goal was to evaluate herbicide efficacy associated with sugar cane harvest residues on M. aterrima control. In absence and presence of sugar cane straw, herbicides were applied in pre-emergence (imazapic, imazethapyr + flumioxazin, diclosulan, s-metolachlor, clomazone, sulfentrazone and sulfentrazone+diuron) and in post-emergence of M. aterrima (imazapic, imazethapyr, bentazon, bentazon + imazamox, lactofen, fomesafen, cloransulan-methyl, carfentrazone and 2,4-D). The treatments sulfentrazone and sulfentrazone + diuron resulted in control higher than 95% in straw absence, causing the highest reductions on aerial part (92%) and root (64%) drought mass of M. aterrima. The presence of sugar cane straw reduced the effect of herbicides applied in pre-emergence. The 2,4-D resulted in weed control higher than 70% and the applications with 2,4-D and carfentrazone caused the highest reductions on weed plant height (28%), aerial part (45%) and root (42%) drought mass. It was possible to conclude that the highest control levels of M. aterrima were obtained with sulfentrazone and sulfentrazone + diuron applied at pre-emergence, in absence of sugar cane straw and, with 2,4-D and carfentrazone, applied in post-emergence, regardless of straw presence.