Diversity of natural enemies and efficacy of biopesticides for the management of Bemisia tabaci (Gennadius) in Bt cotton
Loading...
Date
2017
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Punjab Agricultural University, Ludhiana
Abstract
The studies on "Diversity of natural enemies and efficacy of biopesticides for the
management of Bemisia tabaci (Gennadius) in Bt cotton" were conducted during Kharif,
2016. The population of whitefly and its natural enemies were comparatively less in sprayed
field as against unsprayed fields at Abohar and Muktsar. Among natural enemies of whitefly,
Chrysoperla zastrowi sillemi, spiders and coccinnellids were observed in both sprayed and
unsprayed fields. Diversity of natural enemies associated with whitefly in the cotton
ecosystem was quite less without dominance of any particular specie. Under net house
conditions, Neem oil 1 per cent @ 700 and 500 ml/acre (27.11 to 74.43 per cent reduction
over control) was most effective in reducing number of nymphs of B. tabaci. It was followed
by Metarhizium anisopliae @ 1200 g/acre (27.06 to 58.38 per cent reduction over control).
Neem oil 1 per cent @ 700 and 500 ml/acre (32.00 to 67.54 per cent reduction over control)
proved to be highly effective in minimising the population of whitefly adults under net house
conditions, followed by M. anisopliae @ 1200 g/acre (23.71 to 51.01 per cent reduction over
control). In field conditions, the order of efficacy of biopesticides in case of B. tabaci nymphs
Neem oil 1 per cent @ 700 and 500 ml/acre (53.95 to 94.61 per cent reduction over control) ˃
M. anisopliae @ 1200 and 1000 g/acre (13.41 to 79.99 per cent reduction over control) ˃
Beauveria bassiana @ 1200, 1000 and 800 ml/acre (12.26 to 77.20 per cent reduction over
control) and the order of efficacy of biopesticides in case of B. tabaci adults was Neem oil 1
per cent @ 700 and 500 ml/acre (53.12 to 95.05 per cent reduction over control) ˃ M.
anisopliae @ 1200 g/acre (13.15 to 70.04 per cent reduction over control). It was concluded
that Neem oil 1 per cent @ 700 and 500 ml/acre and fungal formulations (B. bassiana, M.
anisopliae) being safer than chemical insecticides could be included in the IPM of whitefly in
the Bt cotton in field condition.
Description
Keywords
null