Vol. 10, Special Issue 12 (2021)

Author(s):
Sujay Pandey, MK Pathak, MK Pandey, Ashok Tailor and PK Gupta

Abstract:
Onion thrips (Thrips tabaci L.) is a serious pest of onion crop and losses are reported to be as high as 90% (Mote, 1977, Gupta et al., 1984 and Srivastava et al., 1997). Thrips in onion are difficult to control because of succulent nature of leaves, which prevents spray solution reaching the pests and also due to hiding habit of thrips in central axis near the bulb (Shitole et al., 2002). Considering the above problems field trials were conducted in three consecutive years during rabi 2015-16, 2016-17 and 2017-18 seasons on onion variety NHRDF Red to evaluate the efficacy of new insecticides against thrips in onion at NHRDF, Regional Research Station, Karnal (Haryana). A total of 6 treatments with 4 replications in Randomized Block Design were arranged. The application of treatments was started just after appearance of thrips and total 4 sprays were given at 10 days interval. The treatments were T₁-Chlorantaniliprole @ 0.30ml/L., T₂-Emmamectin Benzoate @ 0.40 g/L., T₃-Buprofezin 25 EC @ 1.0ml/L., T₄-Spinosad @ 0.3 ml/L., T₅-Fenpropathrin 30 EC @ 0.6ml/L. and T₆-Control. The thrips population (Nymphs/plant) was counted visually with the help of hand lens on 10 plants selected randomly in each treatment at ten days interval after appearance. The combined data revealed that spray of Spinosad @ 0.3 ml/L. started at 60 days after transplanting (just after appearance of thrips) and subsequently at 10 days intervals performed superior with lowest thrips population (7.65 nymphs/plant). The significantly highest gross yield (292.71 q/ha) were recorded in Spinosad @ 0.3 ml/L. The lowest gross yield (256.80q/ha) were recorded in untreated control. The highest cost benefit ratio (1:7.78) was recorded in Fenpropathrin 30 EC @ 0.6 ml/L. due to lower rate of insecticide.