Tests were performed to study the effects of various
concentrations of the four conventional insecticides malath
ion, pirimiphos—rnethyt deltarnethrin, cy’permethrin. - end
neemazal—? (a botanical insecticide contains 5% Azadiractiri)
on seeds of wheat, maize, broad bean, cowpea. cotton and
squash seeds. Criteria tested were germination rate, growth
rate and chlorophyll content of their seedlings. Results
showed rio significant differences in germination rate of
maize, borad bean and squash seeds after treatment with the
various conventioned insecticides. On the other hand, the
germination of wheat and cowpea seeds was reduced after
neemazal treatments at 1600, 3200 and 6400 ppm. Also, germi
nation of cotton seeds was impaired after malathion, del
tamethrin, cypermethrin and neemazal treatments at all con
centrations. Growth rate of maize, cowpea and cotton seed
lings was markedly affected by all the tested insecticides
while wheat and broad bean seedlings were affected by neem—
azal only.
The chlorophyll A end B contents of wheat. maize, broad
bean and cowpea seedling leaves were not markedly affected
after malathion treatment. On ‘th. other hand, chlorophyll
content was much more lower in cotton seedling leaves and
higher in aquash. Pirimiphos—methyl treatment resulted in
lower chlorophyll content of maize, cowpea. cotton and
squash seedling leaves as compared with the control and did
not affect on wheat and broad bean seedlings
Deltamethrin had no obvious effect on the chlorophyll
content for the various crop seedling leaves
The same phenominon was found with cypermethrin treat
ment, the total chlorophyll content of wheat, broad bean and
squash seedlings was not significantly affected. On the
other hand, it was reduced in maize and cotton and increased
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