Effect of barrier crops as a management tool against Thrips tabaci in onion ecosystem

Impact of barrier crops on the management of Thrips tabaci was studied for two consecutive years. Wheat, mustard and fennel were grown as border crops of onion crop and were compared to imidacloprid treated onion and untreated sole onion crops. Wheat barrier crop (WBC) gave significant result followed by mustard (MBC) and fennel barrier crops (FBC) in relation to reduction in the density of onion thrips. Dispersal of T. tabaci was prevented by presence of vertically tall wheat plants during both the years. The incidence of T. tabaci was variably influenced by abiotic factors. Weather parameters showed positive correlation with thrips population in all the treatments except relative humidity. A non-significant correlation was found between rainfall and thrips density. Yield was significantly higher in WBC than other barrier crops and the control. It was 11.33 and 12.63 t/ha with 2.09 and 3.34 t/ha yield of wheat in 1st and 2nd year, respectively. Wheat as a barrier crop in onion ecosystem managed T. tabaci.