Revista Brasileira De Herbicidas 2016; 15(3): 271-280

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Volatility of clomazone formulations under field conditions

DOI: 10.7824/rbh.v15i3.475

Volatilization plays an important role in the process of herbicide dispersion in the environment. The physicochemical characteristics of the clomazone molecule indicate its volatility potential. The present study aimed to evaluate the volatilization rate of three clomazone formulations under field conditions using indicator plants and wind tunnels. Transparent polyethylene tunnels were placed on a sorghum (Sorghum bicolor) field parallel to the prevalent wind direction, and the herbicide formulations were applied in plastic trays containing 10 kg of sieved soil and placed at the center of the tunnel. The experiment was arranged in a slip-plot design with four replications. The main plots were represented by different formulations of the herbicides: Gamit 360 CS®, Gamit 500 EC® and Gamit Star®, and control plots without herbicide application. The sub-plots represented the distances from the application site: 1, 2, 3, 4, 5, 6 meters. Herbicide injury in sorghum was then assessed at different days after application. The symptoms of all formulations were more intense in the plants that were closer to the application site, and were even more severe in the prevailing wind direction. In general, regardless of the application distance, Gamit 360 CS® caused less injury to the sorghum. It is concluded that among the formulations assessed, Gamit 360 CS® has a lower volatilization rate and, consequently, lower contamination risk of neighboring crops and the environment. The other two formulations have higher volatility potential.