Abstract:
The experiment was conducted in the experimental field of Sher-e-Bangla
Agricultural University, Dhaka, Bangladesh, during the period from October, 2018 to
March, 2019 to evaluate biochemical insecticides applied against major insect pests of
cabbage. The treatments were T
1
: flubendiamide (Belt 24 WG); T
2
: spinosad (Success
2.5SC); T
3
: emamectine benzoate (Proclaim 5G); T
4
: farmer’s practice (cypermethrin
10 EC); T
5
: untreated control (no pesticides). The experiment was laid out in a
Randomized Complete Block Design (RCBD) with three replications. Data were
collected on the insect pest species associated with cabbage crop along with their
nature of damage, seasonal incidence, damaging stage, cabbage head length and
diameter, yield and data on natural enemies. A statistically significant variation was
recorded in terms of all the characters related to growth and yield quality. In terms of
leaf infestation by cabbage semi-looper at 20 DAT the highest number (12) of leaf
infested by semi-looper was for Untreated control and lowest (4) infestation was
observed for flubendiamide (Belt 24 WG). Significant variations were observed
among different number of treatments of cabbage semi-looper at 20 DAT the highest
(11.66) infestation by Cabbage semi-looper was observed for Untreated control and
lowest (6.66) were found for flubendiamide (Belt 24 WG). At 20 DAT the highest
(5.33) infestation by Cabbage cutworm was for Untreated control and lowest (2.66)
were for flubendiamide (Belt 24 WG). At 20 DAT the highest (16) infestation by
Cabbage diamondback moth larvae was for Untreated control and lowest (12) were
for flubendiamide (Belt 24 WG). In terms of number of field spiders at 20 DAT, there
was no significantly variation found among the treatments. For Lady bird beetle, at 20
DAT, there was no significantly variation found among the treatments. But at 60 DAT
the highest (6.66) number of lady bird beetle was observed for untreated control. The
highest diameter of cabbage head (22.2cm) was achieved from flubendiamide (Belt 24
WG) and lowest diameter (15.5cm) of cabbage was collected for untreated control.
The highest height of cabbage head was achieved from flubendiamide (Belt 24 WG)
(11.3cm) and lowest diameter of cabbage for untreated control (6.5cm) and the
highest yield (19.97 ton/ha.) of cabbage head was achieved from flubendiamide (Belt
24 WG) and lowest yield (18.22 ton/ha.) of cabbage was collected for untreated
control. Number of beneficial Arthropods as natural enemies, was also recorded and
data suggested relatively low effect on natural beneficial Arthropods.
Description:
A Thesis
Submitted to the Department of Entomology
Sher-e-Bangla Agricultural University, Dhaka, in partial
fulfillment of the requirements
for the degree
of
MASTER OF SCIENCE (MS)
IN
ENTOMOLOGY