Bio-efficacy and Phytotoxicity of Insecticidal Dusts Used on Brinjal (Solanum melongena L.) for Control of Insect Pests

The bio-efficacy of insecticidal dusts including methyl parathion 2D, fenvalerate 0.4D and cyper-methrin 0.25D was evaluated at 0, 20, 24, 28, 36, 48 and 96 kg/ha against jassids and epilachna beetle on brinjal variety Azad B-1 alongwith their phytotoxic effect on the treated crop. The jassid and epilachna were effectively suppressed with two application of these insecticides å 24 kg/ha upto 15 days, but cypermethrin was less efffective thereafter at 21 days of treatment. The insecticides had their significant superiority å 24 kg/ha dosage over lower dosage of 20 kg but could not had remarkable differences from the higher dosages of 28 kg/ha. There was no phytotoxicity of the dusts of fenvalerate 0.4D and cypermethrin 0.25D and methyl parahion 2D at normal dosages of 20, 24 and 28 kg/ha. Methyl parathion produced 9.93 per cent phytotoxic symtoms after 7 days of treatments at 36 kg dosage which had increased with the increase in dosages at 1.5 × 2x × 4x level as well as repeated application of these insecticides.