Efficacy and Economic Viability of Integrated Pest Management Modules Against Onion (Allium cepa L.) Thrips (Thrips tabaci Linderman)

摘要

An experiment was carried out during rabi season of 2011-12,2012-13 and 2013-14 to evaluate the effective eco-friendly IPM modules for management of thrips (Jhripstabarilln&em&n) in onion. The treatments /modules My- IPM module consisted of planting barrier crops in outer row of maize and inner row of wheat on all sides of the onion plots prior to 7-10 days of onion planting and the seedlings roots were dipped from l/3td of bottom in carbosulfan solution for 2 hr before transplanting as well as sprayof neem oil+carbosulfan solution or neem oil+ profenofos solutions were made whenever thrips cross ETL, M_2: Farmers practice wherein dimethoate or profenofos or carbosulfan insecticides spray was made at 15 days interval or as soon as thrips appeared in the field and M3: untreated control laid out in randomized block design. Both M_1 and M_2 modules significantly reduced the thrips population on onion than M_3 (untreated control). The polar diameter, equatorial diameter, total yield and marketable yield were considerably high in M_1 and M_2 during all three years. However, in 2012-13 and 2013-14, these parameters were significantly higher in M_1. The three years pooled maximum marketable yield (296.51 and 297.13q/ha, respectively) was obtained in M,and M_2were significantly higher than M_3 (contol, without any management of thrips). Thrips population was greatly reduced in IPM module M_1 (10.60) followed by Farmers' practice M_2 (12.46) over the control M_3 (26.86) as pooled of three years indicated the barriers are real restrictors for invasion of thrips. The gross income, additional income and additional yield were similar in modules M, and M_2. However, cost of treatments was considerably higher in module M_2 (Rs. 8258.23) than M_5 (Rs. 2604.67). Higher cost:benefit ratio was obtained in M_1 (1:27.00) than M_2 (1:8.30). It was concluded that adoption of IPM module consisting of planting of border crops of maizein outer row and wheat in inner row on all sides prior to 7-10 days of planting, seedling dip treatment with carbosulfan and neem oil based spray of insecticides when thrips population exceeded ETL reduced the thrips infestation in onion crop coupled with better yield, higher C:B ratio and economic return in onion.