Dietholate no tratamento de sementes de gramíneas forrageiras

Abstract

The aim was to evaluate the protective effect of dietholate on selectivity of clomazone herbicide in forage grasses (Urochloa brizantha cv. Marandu, Urochloa ruziziensis, Urochloa humidicola, Panicum maximum cv. Mombaça and cv. Massai). The experimental design was carried out in randomized blocks, and the treatments were arranged in a 5 X 3 factorial scheme with, 4 repetitions. The first factor corresponded to safener doses applied to the seeds (0, 600, 1200, 2400 e 3000 mL 100 kg-1 of seeds) and the second factor corresponded to the clomazone herbicide doses (0,720 and 1440 g i.a ha-1). It was evaluated the following aspects: visual injury levels within 7, 14 and 28 days after emergency (DAE), tiller number and volumetric density of dry matter (VDDM). Dietholate provides protection to the phytotoxic effects of clomazone herbicide on the species Urochloa brizantha cv. Marandu, Urochloa humidicola and Urochloa ruziziensis, at doses of 600, 1.200 and 2.400 mL 100 kg-1 of seeds. The utilization of safener on the species Panicum maximum cv. Mombaça and Massai shows protective activity specially at doses of 600 and 1.200 100 kg-1 of seeds. The results for injury on the plants indicate significant importance of dietholate as seed safener, for the use of clomazone herbicide on pasture areas.