Abstract:
The study was conducted in the central farm of Sher-e-Bangla Agricultural
University, Sher-e-Bangla Nagar, Dhaka during October 2018 to March, 2019 to
know the effect of biopesticides on major insect pests of cabbage and their natural
enemies. Six treatments were used under the experiment. They were T
1
= Spinosad,
T
2
= SNPV (Spodoptera litura nuclear polyhedrosis virus), T
3
ii
= Spodolure trap, T
4
=
Spodolure trap + Spinosad spray, T
5
= Spodolure trap + SNPV spray and T
6
=
untreated control. The experiment was laid out in a Randomized Complete Block
Design (RCBD) with four replications. Results revealed that the lowest number of
infested leaves by flea beetle (0.33/ 5 plants), tobacco cutworm (0.33/ 5 plants), semilooper
(0.33/
5
plants),
diamondback
moth
(1.33/
5
plants)
and
aphid
(7.50/
5
plants)
were
found in T
4
treatment (Spodolure trap + Spinosad). In case of incidence of
natural enemies, the highest number of lady bird beetle (8.00/plot) and spider
(8.60/plot) was also found from T
4
(Spodolure trap + Spinosad) treatment compared
to untreated control. The highest percentage of healthy plants (91.67%), highest
weight of healthy cabbge head plant
-1
(1.20 kg), marketable cabbage head plot
(19.48 kg) and marketable yield of healthy cabbage head (45.08 t ha
) was found in
T
4
(Spodolure trap + Spinosad) treatment. Spodolure trap in combination with
Spinosad spray may be considered as effective practice for the management of
cabbage insect pests and conservation of natural enemies.
