Study the seasonal incidence of T. tabaci under field condition

Abstract

A field experiment was carried out to evaluate the seasonal incidence of onion thrips at Vegetable Improvement Project, Research Farm Mahatma Phule Krishi Vidyapeeth, Rahuri, Maharashtra, during Kharif and Rabi season of the year 2013-14. Study on seasonal incidence of thrips (Thrips tabaci) was carried out on variety Basvant-780 during kharif and N-2-4-1 during rabi, 2013-14. In kharif season incidence of thrips was observed from 34th August MW (fourteen days after transplanting). The incidence of thrips ranged from 0 to 34.56 thrips per plant. The highest population was recorded in 44th MW (34.56 thrips/plant) (84 days after transplanting). The incidence of thrips was severe from 41th to 45th MW corresponding to mid week of October to first week of November. The population of coccinellids grub observed in kharif season ranged from 1.33-4.27 coccinellids/plant during 35th to 50th MW. The peak activity was noticed during 44th MW October with population 4.27/plant. The studies revealed that correlation of thrips population with maximum temperature (0.6117**) was significant and positive, whereas rainfall, minimum temperature, relative humidity (AM), relative humidity (PM) was non significant and negative. In Rabi season incidence of thrips was observed from 2nd January MW (fourteen days after transplanting). The incidence of thrips ranged from 5 to 32.15 thrips per plant. The highest population (32.15 thrips/plant) was recorded in 14th April MW (98 days after transplanting). The incidence of thrips was severe from 12th to 14th MW corresponding to last week of March to first week of April. The population of coccinellids grub observed in rabi season ranged from 1.10-3.37 coccinellids/plant during 3rd to 15th MW with its peak activity 14th MW.