Dissipation kinetics of trifloxystrobin and tebuconazole on wheat leaves and their harvest time residues in wheat grains and soil.

Following single application of Nativo 75 WG (trifloxystrobin 25% + tebuconazole 50%) on wheat crop @ 300 and 600 g ha(-1), resulting in active application of trifloxystrobin @ 75.0 and 150.0 g a.i. ha(-1) and tebuconazole @ 150 and 300 g a.i. ha(-1), the average initial deposits of trifloxystrobin on wheat leaves were 5.54 and 8.30 mg kg(-1), and that of tebuconazole were 14.66 and 27.94 mg kg(-1), respectively. Half-life values for trifloxystrobin were observed to be 2.80 and 2.51 days whereas those for tebuconazole were found to be 2.46 and 1.85 days at recommended and double the recommended dosages, respectively. The residues of trifloxystrobin and tebuconazole dissipated to the extent of >89% at both the dosages after 7 days. Wheat grain samples at harvest having pre harvest interval of 140 days did not show the presence of trifloxystrobin and tebuconazole at their determination limit of 0.01 mg kg(-1).