Bioefficacy and Residues of Phorate and Quinalphos in Upland Paddy at Medium High Altitude

Soil application of granular phorate and quinalphos in furrow and broadcast applications @ 0.5,1.0 and 2.0 kg. a.i./ha resulted in deposits ranging from 2.2 to 6.0 ppm, and 1.2 to 3.4 ppm, respectively. These deposits dissipated more than 50% in 45 days, and reached below detectable level in 75 -105 days. The half - life (RL_so) ranged from 22 to 30 days and T (BDL) from 93 to 206 days. Both insecticides were effective for controlling insect pests of paddy. Phorate was better than quinalphos. Maximum yield of paddy and straw was recorded in the plots treated with phorate.