Evaluation of new systemic and contact insecticides against insectpest complex of cotton
Field evaluation of new insecticidal molecules was done against sucking pests and bollworms of cotton. The new molecules tested were methomyl (Lannate ® 40 SP), thiodicarb (Larvin ® 75 WP), triazophos (Hostathion ® 40 EC), lamda cyhalothrin (Karate ® 40 EC), profenofos+cypermethrin (Polytrin-C ® 44 EC), triazophos+deltamethrin (Spark ® 36 EC), indaxocarb (Auvant ® 14.5 SP), chlorpyriphos+cypermethrin (Chop ® 55 EC), endosulfan (Endocel ® 35 EC) and dimethoate (Rogor 30 EC). Methomyl recorded the lowest (2.00) aphid population which was on par with thiodicarb (2.69) followed by other insecticdes. Thiodicarb recorded the lowest (4.17) thrips population followed by indoxacarb and other treatments. The insecticidal treatment chlorpyriphos+cypermethrin recorded minimum (1.2 per plant) number of larvae and significantly superior over triazophos+ deltamethrin (4.2 larvae per plant) but on par with rest of the treatments on three days after first spray during first season. Methomyl recorded the lowest (0.87) bollworm population and significantly superior over profenofos+cypermethrin (3.47), endosulfan (4.00) and control (13.20), but was on par with rest of the treatments during three days after fourth spray. The cost : benefit ratio was maximum in methomyl (1 : 2.68) followed by chlorpyriphos+cypermethrin, profenofos+cypermethrin and indoxacarb.