Bio-rational management of rose bollworm, Helicoverpa armigera

A field experiment was conducted at farmer’s field of Vowal village, Gazipur, Bangladesh during January to May 2021 to develop an effective bio-rational based management approach against rose bollworm, Helicover paarmigera. Six treatments, such as: T₁: Sex pheromone Mass trapping T₂: Sex pheromone Mass trapping + Azadirachtin (Bio-neem plus 1EC) @ 1ml/L of waterat 10 days interval; T₃: Sex pheromone Mass trapping + spraying of HNPV @ 0.2 g/L of water at 10 days interval; T₄: Sex pheromone Mass trapping + spraying of Spinosad (success 2.5 SC ) @ 1.2 ml/L of water at 10 days interval; T₅:Farmers practice (spraying of synthetic insecticides, Proclaim 5SG @ 1g/L ) at 7 days interval; T₆: Untreated control were evaluated following RCB design with three replications. The results indicated that T₃ treatment, Sex pheromone Mass trapping + spraying of HNPV @ 0.2 g/L of water at 10 days interval showed the best performance reducing plant and flower infestation and increasing marketable yield followed by T₄ treatment, Sex pheromone Mass trapping + spraying of Spinosad (Success 2.5SC ) @ 1.2 ml/L of water at 10 days interval. In case of maximum marginal benefit cost ratio, T₄ treatment showed best performance.