BIORATIONAL MANAGEMENT OF LEAF FEEDING INSECT PESTS OF CABBAGE

Abstract

An experiment was conducted in the experimental field of Sher-e-Bangla Agricultural University, Dhaka, Bangladesh during the period from October, 2020 to February, 2021 to evaluate the effectiveness of some biorationals against leaf feeding insect pests of cabbage. The experiment was laid out in a Randomized Complete Block Design (RCBD) with four replications. Six treatments, viz. T 1 (Spinomax 45SC @ 0.5 ml/L of water at 7 days interval); T (Biomax 1.2EC @ 2 ml/L of water at 7 days interval); T (Bioneem plus 1EC @ 3 ml/L of water at 7 days interval); T 4 ii

3 (Antario @ 2 g/L of water at 7 days interval); T (Fytomax @ 2 ml/L of water at 7 days interval) and T 6 5 (untreated control) were used. Among the management practices, the lowest percentage of leaf infestation of cabbage by tobacco caterpillar (9.58%) and jute hairy caterpillar (6.88%) was found in T treated plot that reduced the highest leaf infestation over control (72.73% and 68.67%, respectively); whereas the highest percentage infestation by tobacco caterpillar (35.13%) and jute hairy caterpillar (21.96%) was found in untreated plot (T 1 ). The lowest mean incidence of tobacco caterpillar (5.74 larvae/6 plants) and jute hairy caterpillar (4.15 larvae/6 plants) was found in T that reduced highest incidence over control (49.52% and 58.95%, respectively); whereas the highest values of all these parameters were achieved from untreated control treatment (T 6 1 ). The lowest cabbage head infestation (23.64%) was recorded in T 1 , that gave the highest yield of cabbage (75.80 t ha -1 ) that increased the highest yield over control (96.93%). From the above study, it was found that the treatment T comprised of Spinomax 45SC @ 0.5 ml/L of water at 7 days interval gave the highest performance compared to those of all other treatments used in the present study. Spinomax 45SC may be used for the management of leaf feeding insect pests of cabbage.