Investigations on Seasonal Incidence and Management of Mirid Bug, Poppiocapsidea Biseratense Distant Bt Cotton
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Date
2013
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UAS Dharwad
Abstract
Investigations on seasonal incidence and management of mirid bug, Poppiocapsidea
biseratense (Distant) in Bt cotton was carried out at MARS, UAS, Dharwad during 2011-12
and 2012-13 indicated that the incidence of mirid bug started during 38th Meteorological
Standard Week (0.17 bug/10 squares) and reached maximum population 5.74 bugs at 47th
MSW. Thereafter, the population declined to 3.12, 1.25, 0.79, 0.57 and 0.15 bugs between
48th and 52nd standard weeks of November and December month.
During roving survey the highest population of mirid bug was observed in Haveri
(average of 8.26 and 6.80 bugs/10 squares) whereas, the lowest incidence was recorded in
Bagalkot district with an average of 4.02 and 3.20 bugs during 2011-12 and 2012-13,
respectively).
In fixed spot survey, the peak incidence of the pest was observed during November II
fortnight (8.80 bugs/10 squares) in Dharwad. But, in Belgaum and Haveri district the peak
incidence registered (6.20 and 12.2 bugs/10 squares) during October II fortnight,
respectively.
The effect of different dates of sowing on incidence of mirid bug revealed that the
early sown cotton crop (June 1st and June 15th) had registered lowest mirid bug population
with highest GOB and yield. The late sown crop suffered much with the increased incidence
followed by lowest yield.
Field screening of cotton cultivars for their reaction to mirid bug damage revealed
that, Chiranjeevi (HxH BG-II), RCH-2Bt and Bunny (NBt) appeared as less prone to mirid
bug attack with highest yield. While, the lowest yield was recorded in Nathbaba, DHB-915
and DHH-11 which were more prone to mirid bug.
The morphological characters of cotton plant viz., gossypol gland, trichome density,
and trichome length were exhibited positive and leaf thickness had negative correlation with
mirid bug incidence. The amount of phenol, gossypol and tannin had a negative and total
sugar had a positive correlation with incidence of mirid bug.
The efficacy of different components tested against mirid bug revealed that the
fipronil 5 SC @1 ml/lit found to be superior followed by acephate 75 WP @ 1.0 g/lit in
suppressing the mirid bug population.