RELATIVE EFFECTIVENESS OF A NEW INSECTICIDE AGAINST MUSTARD APHID, Lipaphls erysimi (KALTENBACH) ON RAPESEED- MUSTARD UNDER FIELD CONDITIONS

摘要

The studies were conducted at the Oilseed Research Farm, PAU, Ludhiana for three years and for one year at Regional Research Station, Bathinda. The new insecticide Thiamethoxam (Actara 25 WG) with four dosages was compared with already recommended insecticides viz. dimethoate (Rogor 30 EC) and oxydemeton methyl (Metasystox 25 EC). Aphid population was suppressed by all insecticides after one day of treatment at Ludhiana and Bathinda. After seven days of treatment at Ludhiana, the difference in numberof aphids was non-significant among plots treated with Actara, Rogor and Metasystox but the percent mortality data indicates that it is above 90 % in Actara treated plots whereas in Rogor and Metasystox treated plots it is below 70%. The yield data shows that a significantly superior yield was obtained in case of Actara treated plots. At Bathinda, the percent mortality data shows that in case of Rogor and Metasystox treatments the number of aphids increased to significant levels after four and seven days whereas in case of Actara treated plots the percent mortality varies from 65.7 to 86,4. The yield was also significantly superior in Actara treated plots. The results indicated that Actara had quick knock down effect, a day after insecticide application and mortality of aphids becomes higher after four and seven days after treatment No significant difference in number of aphids among Rogor and Metasystox indicates that these are effective but slower in action than Actara.