Papers

Summary

This study aimed to determine the mobility of sulfentrazone in two soil classes as a function of increasing rain indices, as well as possible influences of chemical and physical properties of soils with different iron oxide contents (Red Latosol and Chernosol), on herbicide action. The containers consisted of 36 PVC tubes (10 cm diameter x 50 cm long), which were filled with the soils and saturated in 65% (w/w) water followed by sulfentrazone (800 g ha-1 of a.i.) application on the exposed area. Daily rainfalls of 10 mm were subsequently simulated and, as the desired rain indices were reached (30, 60 and 90 mm), six PVC tubes from each soil (with and without application) were disassembled. Five sorghum (Sorghum bicolor) seeds were seeded on soil at depths of 2.5; 7.5; 12.5; 17.5; 22.5 and 30.0 cm, and maintained under greenhouse conditions for 15 days for germination and initial growth evaluation. Also, evaluation of possible morphophysiological changes that could be characterized as toxic effects of the product wascarried out and shoot length up to the last visible ligule was measured. The shoots were bagged and dried in a forced draught over (70 oC for 96 h) to dry matter determination. There was a uniform distribution of the product on the length of the tube, proportional to the rainfall on Chernosol; on Red Latosol, sulfentrazone had little mobility, remaining on the top 2.5 cm, regardless of the rainfall.