Persistence and phytotoxicity of soybean herbicides on successive sunflower crop

The objective of this work was to avaluate the residual effect of imazaquin, imazethapyr and diclosulam, applied on soybean, on successive sunflower crop. In the main plots, sunflower was sowed 60 and 90 days after application (DAA) of imazaquin and diclosulam and 45 and 75 DAA of imazethapyr. The subplots consisted of imazaquin (150 g/ha), imazethapyr (70 g/ha) and diclosulam (33.6 g/ha) applied on soybean and an untreated control. The sunflower sowed 90 and 75 DAA of imazaquin and imazethapyr applied on soybean, respectively did not show symptoms of phytotoxicity. The diclosulam caused a total reduction on sunflower stand in two periods of sunflower sowing. Herbicide injury potential, as indicated by sunflower yield, was diclosulam > imazaquin > imazethapyr.