Field Performance of Different Management Approaches Against Thrips (Scirtothrips dorsalis Hood) for Improved Growth and Yield of Capsicum (Capsicum annuum L.)

Abstract

Thrips infestation is a major constraint to capsicum production under open-field conditions. Scirtothrips dorsalis Hood is considered one of the most destructive pests of capsicum throughout the growing season. Considering public concerns regarding excessive pesticide use in vegetable production, the present study was undertaken to evaluate eco-friendly management approaches for reducing thrips infestation and improving capsicum yield. A field experiment was conducted at the Professor Dr. Purnendu Gain Field Laboratory, Khulna University, to assess the efficacy of different management approaches on capsicum varieties of different fruit colors and to evaluate their economic profitability under field conditions. The factorial experiment consisted of twelve treatment combinations comprising Factor A: three capsicum colors (green, yellow, and purple) and Factor B: four management treatments (kaolin, neem oil, chemical insecticide [Beldor], and untreated control). The experiment was laid out in a Randomized Complete Block Design (RCBD) with three replications. The results showed that growth parameters, yield components, fruit yield, and profitability were significantly influenced by capsicum color and management practices. Overall, purple capsicum plants treated with kaolin exhibited superior plant vigor, plant height, leaf number, and chlorophyll content compared with untreated plants. The highest fruit yield (44.86 t ha⁻¹) was obtained from the combination of purple capsicum and kaolin application, whereas the lowest yield (16.12 t ha⁻¹) was recorded in untreated green capsicum plants. Flowering occurred more than four days earlier in kaolin-treated plants compared with the control treatment. Kaolin application reduced thrips infestation by 73.76% compared with untreated plants. The combined effects of reduced pest infestation and increased yield resulted in the highest net profit of Tk. 2,707,828 ha⁻¹. The findings suggest that cultivation of purple capsicum combined with kaolin application can serve as an effective and environmentally friendly management strategy for reducing thrips infestation, increasing yield, and maximizing profitability. This approach may contribute significantly to sustainable capsicum production in Bangladesh.