Effect of different management practices on sucking insect pests, disease incidence, and natural enemies in tomato plants

Abstract: Tomato (Solanum lycopersicum L.) is a nutritionally important vegetable crop, rich in vitamins, minerals, fiber, and antioxidants; however, its production in Bangladesh is severely constrained by sucking insect pests, and various management practices have been adopted to address these challenges. In this study, a field experiment was conducted with five treatments-cultural, mechanical, biorational, sequential bio-pesticide application, and an untreated control to evaluate the effects of these management approaches on the population dynamics of sucking insect pests, namely aphids, whiteflies, and thrips, in tomato, as well as on the incidence of leaf curl disease and the abundance of their natural enemies. Among the treatments, sequential management maintained the lowest populations of sucking pests, reducing aphids to 7.8 plant⁻¹ compared with 15.4 plant⁻¹ in control and lowering whitefly to 8.4 plant⁻¹ versus 16.4 plant⁻¹. Thrips were also minimized (3.0 plant⁻¹) compared with control (5.0 plant⁻¹). Leaf curl incidence was lowest under sequential (6.4%) and biorational (9.2%) treatments. Natural enemy abundance was highest in the control plots, while sequential and biorational treatments recorded comparatively lower population. Overall, sequential management proved most effective in suppressing pests and disease while maintaining ecological balance, suggesting its suitability as a sustainable tomato pest management strategy. 

Keywords: Pest population dynamics, Bio-pesticide, Sequential management, Tomato production