Efficacy and selectivity of imazapic isolated or associated with other herbicides applied with and without sugarcane straw

Abstract

The management of weeds in the sugarcane is based on the integration of cultural methods, mechanical, physical and chemical. As a physical measure, there is the presence of waste straw from mechanical harvesting, which may act as a barrier, reducing the infestation of weeds or as a physical barrier on the action of herbicides on weed control when applied in preemergence of these plants on the straw of the sugar cane. As a result, the objective of this work is analyze the influence of the layer of straw on the ground in the action of imazapic and mixtures used in the cultivation of sugar cane in weed control in areas where sugar cane is harvested mechanically without straw burning. The experiment was performed in Santa Fe - Paraná, with sandy soil. The treatments in the experiment were isolated imazapic, imazapic + [diuron + hexazinone], and tebuthiuron imazapic sulfentrazone + [diuron + hexazinone], applied in the absence and presence of straw. In general, the presence of straw contributed to control of Brachiaria decumbens and Ipomoea grandifolia. The effectiveness of herbicide treatments in the presence of straw was similar to or higher than the performance of the same in the absence of straw. The presence of straw does not affect the operation of imazapic in weed control, and may even increase its effectiveness to control. All herbicide treatments were harmless to the tiller, regardless of the presence of straw.