IDENTIFICATION OF INSECT PESTS IN SWEET POTATO AND THEIR MANAGEMENT

Abstract

The present study regarding identification of insect pests in sweet potato and their management has been conducted during rabi season (November 2016 to March 2017) in the experimental field of Sher-e-Bangla Agricultural University, Dhaka. The variety of BARI Sweet Potato 8 was used as test crop. Six insecticidal treatments with one untreated control were tested in this study. They were T1: Emamectin benzoate @ 2 ml/L of water; T2: Carbofuran 5G @ 15 kg/ha at 60 days after sowing; T3: Diazinon 10G @ 12 kg/ha at 60 days after sowing + Azadiractin @ 3 ml/L at 10 days interval (3 times application); T4: Sevin 85WP @ 3 g/L + Admire @ 1 ml/l at 15 days interval (3 times application); T5: Voliam flexi 300SC @ 1 ml/L at 15 days interval (3 times application); T6: Lamda cyhalothin @ 1 ml/L at 10 days interval (3 times application) and T7: Untreated control. The experiment was laid out in Randomized Completely Block Design (RCBD) with three replications. Under the present study 9 different species of insect pests were recorded and they were belonged to 9 family under 3 orders. Among the insect pests it was observed that sweet potato weevil was more destructive for storage roots of sweet potato. Data revealed that for sweet potato weevil, the lowest number of sweet potato weevil was T2 (1.67), while the highest number from T7 (6.73) treatment. At 15 days early harvest, in consideration of infestation level of storage roots in number and weight basis, the lowest infestation was recorded from T2 (3.69% and 5.68%), whereas the highest infestation (12.25% and 12.98%) was observed from T7 treatment. At optimum days harvest, for infestation level of storage roots in number and weight basis, the lowest infestation was recorded from T2 (4.49% and 6.49%), whereas the highest infestation (13.56% and 14.16%) was observed from T7 treatment. After 15 days from optimum harvest, in case of infestation level of storage roots in number and weight basis, the lowest infestation was recorded from T2 (5.31% and 6.93%), whereas the highest infestation (16.37% and 17.05%) was observed from T7 treatment. The highest yield was recorded from T2 (41.86 t/ha), whereas the lowest from T7 (30.27 t/ha) treatment. It was revealed that Carbofuran 5G @ 15 kg/ha at 60 days after sowing was the best for the controlling insect pests of sweet potato among different control measures under the study and also attaining highest yield of storage roots.