Department of Agronomy, CCS Haryana Agricultural University, Hisar-125 004 (Haryana), India.
1 Department of Agronomy, Punjab Agricultural University, Ludhiana-141 004 (Punjab), India.
The degradation of sulfosulfuron was investigated in sterilized and unsterilized soils (pH 8.2) spiked at 64 μg a. i./ha (64 ppb) under laboratory conditions at 25°C and a moisture content corresponding to field capacity using maize bioassay. Degradation data in the two soils did not fol1ow first order kinetics. Degradation of sulfosulfuron was faster in unsterilized soil than in sterilized soil, demonstrating the importance of microbes in breakdown process. Half-life of chlorsulfuron sulfosulfuron was 93 days in unsterilized soil, whereas it was 120 days in sterilized soil. This study shows that if sulfosulfuron is applied at recommended rate of 25 g/ha (12.5 ppb) then risk of residual carry over to succeeding crop of sorghum is possible.
