The Study Effect of Residual in Some of Sulfonylurea Herbicides on Sunflower (Helianthus Annuus) and Cotton (Gossypium Hirsutum)

In order to study the effect of residual in some of sulfonylurea herbicides on sunflower and cotton, two randomized complete block design was conducted with ten treatments in four replications for both of plants. Treatments included: sulfosulfuron (Apirus), idosulfuron+mesosulfuron (Chevalier), chlorsulfuron (Megaton), sulfosulfuron+metsulfuron methyl (Total), idosulfuron+mesosulfuron+ mefenpyr (Atlantis) that all of the herbicides were used at three doses, and no-herbicide control. Soil was sprayed with the herbicides and the treated soils were transferred to the greenhouse after four months, therefore, sunflower and cotton were planted in the pots included the soils. Length and dry weight of different plant organs (root, stem and leaf) and total dry weight were measured at four-leaf stage. The results showed that the treatments had negative effects on the most of measured characters in sunflower and sulfosulfuron+ metsulfuron methyl and chlorsulfuron at highest dose (44 and 22.5 g ai ha-1, respectively) had the most harmful effects on the sunflower and reduced dry weight by 82.97% and 70.31% in comparison of control, respectively. Whereas, height and root length of cotton had been just affected of the herbicides and sulfosulfuron+metsulfuron methyl and chlorsulfuron at highest dose had the most negative effects on height and root length of cotton. In attention to the gotten results, we can conclude that sunflower is probably the more sensitive than cotton into sulfonylurea herbicides residual.