Alternatives to chemical scavenging of clumps of guinea grass and signal grass clumps in sugarcane ratoon

Abstract

In sugarcane areas of Parana State, Panicum maximum (guinea grass) and Brachiaria decumbens (signal grass) stand out as weeds with difficult control and may compromise the useful period sugar cane crop. This research aimed to evaluate alternatives to chemical scavenging of P. maximum and B. decumbens clumps in sugar cane crop. This way, two experiments were conducted in field conditions by using a complete randomized block design with four replications for the first and five for the second one. In the first experiment, hexazinone and diuron + hexazinone herbicides were evaluated at 0, 10, 11.7, 13.3, 15 and 16.7% concentrations. In the second one, isoxaflutole herbicide was used at 0, 1.5, 3.0 and 4.5% concentrations. Visual control evaluations were performed at 4, 10, 20 and 30 days after treatments application. Diuron + hexazinone and hexazinone herbicides were effective in controlling P. maximum and B. decumbens at 10% concentration. Regarding to isoxaflutole, it was necessary a minimum concentration of 4.8 and 4.2% for maximum efficiency control of P. maximum and B. decumbens sprouting, respectively.