An experiment was conducted in Passo Fundo, Rio Grande do Sul, Brazil, to evaluate the effects of treatment of oat seeds (Avena sativa) with naphthalic anhydride safener (AN) on the herbicide selectivity used for ryegrass (Lolium multiflorum) control. The experimental design used was a split-plot one, in randomized blocks, with four replications. The treatments consisted of oat seed treated or not with AN (5 g kg-1 seed) as main plots, and of five herbicide treatments, one check without ryegrass and herbicide and one check without ryegrass control, as sub plots. Herbicide treatment used were diclofop (284 e 426 g ha-1), sulfentrazone (600 g ha-1), isoxaflutole (52,5 g ha-1) and clomazone (1000 g ha-1). Ryegrass percentage control, visual phytotoxicity of herbicides and characteristics associated with the oat crop as shoot dry weight, plant height, number of plants and panicles per area, weight of 1000 grains and grain yield were evaluated. Results showed that treatment of oat seeds did not increase herbicide selectivity, with exception of shoot dry weight, for the sullfentrazone. Herbicides that provided the best ryegrass control level caused the greatest phytotoxic damage to the oat crop.
Avena sativa; safener; plant injury; grain yield
