Journal of Experimental Agriculture International

Aims: This study is aimed to know the effect of biopesticides on insect pests, predators and yield of cabbage.

Study Design: The experiment was laid out at a randomized complete block design with four replications.

Place and Duration of Study: Central farm of Sher-e-Bangla Agricultural University, Bangladesh during the period from October 2018 to March 2019.

Methodology: The experiment was conducted with six treatments viz. T₁= Spinosad @25 ml/ha at 7 days interval , T₂= SNPV (Spodoptera litura nuclear polyhedrosis virus) @ 2.47/ha at 7days interval, T₃= Spodolure trap @ 1/6 plot at 14 days interval, T₄= Spodolure trap + Spinosad spray, T₅= Spodolure trap + SNPV spray and T₆= untreated control.

Results: The lowest infested leaves per five plants by flea beetle (0.33), tobacco cutworm (0.33), semi- looper (0.33), diamondback moth (1.33), aphid (7.50), was found in treatment (Spodolure trap + Spinosad).The population of natural enemies per plot was also recorded and highest population of lady bird beetle (8.00) and spider (8.60) was also observed from Spodolure trap + Spinosad treatment as compared to untreated control. The highest percentage of healthy plants (91.67), maximum weight of healthy cabbge head plant^-1 (1.20 kg), marketable cabbage head plot^-1 (19.48 kg) and marketable yield of healthy cabbage head (45.08 t ha^-1) was found with Spodolure trap + Spinosad treatment.

Conclusion: It is concluded that Spodolure trap in combination with Spinosad spray may be effective practice for the management of cabbage insect pests.