Abstract:
In order to study the efficacy of different neem products for the control ofjute
mites (yellow mite, Poivplzago:orsonernus lot its Banks and red mite.
Tetronvclzus hioculatus Wood- Mason). and its effect on predators, several
experiments were conducted at Iaboratoiy, greenhouse and in the field of
Bangladesh Jute Research Institute during the period from March to December
2007. In the greenhouse condition, the highest % mortality (67.37) was observed
in the plot treated with 3% neem oil but it had some phytotoxie effect on jute
leaves, therefore from the green house experiment. 2% neem oil was selected as
most appropriate dose for field experiment as higher dose cause phytotoxicity on
plant. In field experiment, highest % reduction of infestation over control
(79.23'h lowest number of nodes per plant (53.25). highest plant height (3.28 iii),
and highest % of yield increased (39.33%) over control were observed in the
plot treated with 2% neem oil. Benefit cost ratio was also found highest (16.55)
from 2% nccm oil treated plot. In late jute seed crop, the highest % reduction of
infestation by red mite (75.17%) and yellow mite (75.28). maximum 1000 seed
weight (2.53 g). % germination (86%) and seed vigour (56) was recorded from
2% necm oil treated plots. It was observed that Acarieide such as Sulphur.
Chlorinated hydrocarbon, Organophosphate and Abamectin killed all the
predators of' jute mites tested while; there is no harmful effect of neem products
on predators.
Description:
A Thesis
Submitted to the Department of Entomology
Sher-e-Barrgla Agricultural University, Dhaka,
in partial fulfilment of the requirements for the degree of
MASTER OF SCIENCE (M.S.)
IN
ENTOMOLOGY
SEMESTER: JULY- DECEMBER, 2007
