Abstract:
An experiment was conducted to evaluate of some chemical and nonchemical
management practices against the epilachna beetle attacking brinjal
at the experimental farm of Sher-e-Bangla Agricultural University. The study
comprised seven treatments such as mechanical control, Cypermethrin 10
EC, Sevin 85 SP, Chlorpyriphos 20 EC, neem seed kernel, mechanical
control with application of neem seed kernel and an untreated control. The
experiment was carried out in Randomized Completely Block Design
(RCBD) with three replications. Sevin 85 SP, Cypermethrin 10 EC and
Chlorpyriphos 20 EC reduced more than 90% of the epilachna beetle
population in the brinjal field. Mechanical control in combination with neem
seed kernel spray also provided more than 80% reduction of the pest. Sevin
85 SP gave the highest fruit yield (20.0 tlha) of brinjal but Cypermethrin 10
EC and Chlorpyriphos 20 EC produced 19.90 tlha and 16.20 tlha yield,
respectively. Sevin and Cypermethrin also increased more than 200% yield of
brinjal over control. Chlorpyriphos and mechanical control with neem seed
kernel application increased more than 150% brinjal yield. Negative linear
relationship was observed between percent leaf infestation and yield, and
percent plant infestation and yield of brinjal. The highest benefit-cost ratio
(12.34) was observed in Sevin 85 SP. Almost equal BCR was calculated in
Cypermethrin and Chlorpyriphos (7.38 and 7.34, respectively) treated plots.
Mechanical control with application neem seed kernel, and neem seed kernel
only gave the BCR of 5.39 and 4.89, respectively. The lowest BCR 2.37 was
obtained in mechanical control plots. Sevin 85 SP, Cypermethrin 10 EC and
Chlorpyriphos 20EC had strong negative impact on the natural enemy
population. Mechanical control with application neem seed kernel, and neem
seed kernel had moderate effect on natural enemies.
Description:
A THESIS
Submitted to
Sher-e-Bangla Agricultural University, Dhakn
In partia' fulfillment of the requirements
for the degree of
MASTER OF SCIENCE (MS)
IN
ENTOMOLOGY
SEMESTER: JULY-DECEMBER, 2007