EVALUATION OF DIFFERENT NPV FORMULATIONS AND BIOAGFNTS IN THE MANAGEMENT OF Helicoverpa armigera (Hubner) ON SUNFLOWER
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Date
2001-08-06
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UNIVERSITY OF AGRICULTURAL SCIENCES GKVK BANGALORE
Abstract
Investigations on testing the efficacy of NPV purified through ordinary and
deep freeze centrifuge, development and evaluation of different NPV
formulations and evaluation of different bioagents under field conditions against
Helicoverpa armigera on sunflower have revealed the following.
There was no significant effect on recovery and virulence of POB's with
the increase in centrifugation speed from 2000 rpm to 10000 rpm though
temperature was increased upto SS.BOOc at 10000 rpm in ordinary centrifuge.
Rise in temperature from -5°c to 25°c also did not have effect on recovery and
virulence of POB's as the temperature was below critical temperature.
Flyash based dust formulation was found to be more effective though all
other three dust formulations (Chalk powder, talc and lignite) were found
significantly less effective compared to aqueous formulation. Starch based WP
formulation was found to be more effective followed by bentonite and talc.
Neem oil based formulation was significantly more effective compared to
aqueous formulation and pundi oil based formulation was on par with the latter.
Based on the per cent reduction in larval population overall per cent head
damage and yield among the different bioagents tested NPV (g) 250 LE per ha
was found to be significantly more effective which was at par with the NSKE
five per cent followed by Nomuraea riieyi (1 kg/ha), Baciiius thuringiensis (1 kg/ha)
and Beauveria bassiana (1 kg/ha). However two sprays of endosulfan (2ml/l) at
15 days interval was found significantly more effective compared to all the
bioagents.
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