Comparative Efficacy of Botanical and Chemical Insecticides against Major Lepidopteran Pest of Cauliflower (Brassica oleracea var. botrytis L.) under Field Conditions

Abstract

Cauliflower (Brassica oleracea var. botrytis L.) is an economically important vegetable crop widely cultivated for its nutritional and commercial value. However, severe infestations of insect pests, particularly diamondback moth (Plutella xylostella L.) and tobacco caterpillar (Spodoptera litura Fabricius), significantly reduce yield and market quality. Excessive dependence on synthetic pesticides has resulted in environmental pollution, pesticide resistance, and health-related concerns, creating the need for sustainable pest management alternatives. The present study evaluated the efficacy of selected botanical extracts against major insect pests of cauliflower under field conditions and compared their effectiveness with a conventional chemical pesticides. The experiment was conducted using a randomized complete block design (RCBD) with multiple treatments including tobacco leaf extract, papaya leaf extract, dhatura extract, chlorpyrifos and an untreated control. Data on pest infestation, plant growth, and yield attributes were collected and analyzed using analysis of variance (ANOVA). All botanical treatments significantly reduced pest infestation compared with the untreated control (p < 0.05). Among the botanical treatments, tobacco leaf extract showed the highest efficacy against P. xylostella and S. litura, resulting in lower leaf damage (63.46% over control) and improved curd yield (84.63% over control). Chlorpyrifos demonstrated the maximum suppression (81.79% reduction over control) of pest infestation and produced the highest marketable yield (113.58% over control); however, botanical treatments showed promising eco-friendly potential for sustainable pest management.