Selectivity of Pre-Emergence Herbicides Applied on Forage Grasses

This study aimed to evaluate the selectivity of pre-emergence herbicides on yield and seed quality of Brachiaria brizantha cv. Brizantha and Brachiaria decumbens cv. Basilisk. The herbicides evaluated were: diuron (800 and 1.600 g ha(-1)), ametryn (625 and 1.250 g ha(-1)), imazaquin (75 and 150 g ha(-1)), imazethapyr (50 and 100 g ha(-1)) and flumetsulam (70 and 140 g ha(-1)), plus a control without herbicide application. The species were evaluated separately in the field. The experiments were arranged in a randomized block design with four replications. The herbicides ametryn (625 g ha(-1)), imazaquin (75 and 150 g ha(-1)), imazethapyr (50 and 100 g ha(-1)), and flumetsulam(70 and 140 g ha(-1)) provided the highest selectivity to B. brizantha plants, while for B. decumbens, diuron (800 and 1.600 g ha(-1)), ametryn (625 and 1.250 g ha(-1)), and imazethapyr (50 and 100 g ha(-1)) were more selective, especially diuron, at the lowest dose. However, the tested herbicides do not affect the yield and quality of the seeds of the forage grasses studied.