Papers

Summary

The objective of this study was to determine the mobility of sulfentrazone in two soils classes as a function of increasing rain indices, as well as possible influences of the chemical and physical properties of soils with different iron oxides contents, on the herbicide action. The containers were 36 PVC tubes (10 cm diameter X 50 cm long). The containers were filled with soils and irrigated in 65%(w/w) and, then, the application of sulfentrazone (800g a.i/ha) was done on the exposed area. Subsequently, daily rainfalls of 10mm were simulated and, as the desired rain indices were reached (30, 60 and 90mm), six PVC tubes from each soil (with and without application) were disassembled. Five sorghum (Sorghum bicolor) seeds were sowing on soil from the depths 2,5-7,5-12,5-17,5-22,5-30,0 cm, and were maintained in a greenhouse for 15 days to evaluation of the germination and initial growth. After this time, an evaluation of possible morphophysiological changes that could be characterized as toxic effects of the product was done and the length of the shoot up to the last visible ligule. After measurement the shoots were dried in a forced draught over (70°C for 96h) to determine the dry matter. The results indicated that on the Dusky Red Latosol (Typic Acrustox) the product was percolated down to 12,5 cm with 90mm rainfall and on the Yellowish Red Latosol (Typic Acrustox) the sulfentrazone had little mobility, staying on the top 7,5cm, independently the rainfall.