Screening of Different Onion Varieties Against Onion Thrips and Evaluation of Botanical and Chemical Management Strategies in District Charsadda, Khyber Pakhtunkhwa

Abstract

Onion thrips, Thrips tabaci Lindeman, is considered one of the most injurious insect enemies of onion and can cause reduced growth, yield and marketable quality if not controlled on time. A field study was carried out at the Agriculture Research Station, Charsadda, Khyber Pakhtunkhwa province to test three onion varieties: Winner F1, Premium and Nikerson; and four management treatments: neem oil, Mexican marigold extract, moringa extract and lambda cyhalothrin; and an untreated control. The experiment was laid out in randomized complete block (RCB) design with split-plot experimental design and three replications. Three applications were sprayed and thrips population density was recorded at 3, 7 and 10 days after spray (DAS) and bulb diameter, yield and cost-benefit ratio were recorded at harvest. Lambda cyhalothrin and moringa extract had the lowest overall thrips population (9.49 and 10.95 thrips plant^-1 respectively) while the control had the highest population (17.64 thrips plant^-1). Nikerson had the lowest mean number of thrips per plant (9.90 thrips plant^-1) among varieties and Winner F1 had the highest (17.97 thrips plant^-1). Premium had the highest yield (34,080 kg ha^-1) whereas Nikerson had the largest bulb diameter (8.72 cm). The highest mean yield (31,614 kg ha^-1), net benefit (Rs 460,850 ha^-1) and cost-benefit ratio (14.6) were recorded with lambda cyhalothrin. The results suggest Premium containing lambda cyhalothrin was the most productive and most economically viable, and Nikerson might be considered in situations where varietal tolerance is desired. Botanicals can be used to supplement an IPM program in the low to moderate thrips pressure range, particularly moringa extract and Mexican marigold.