Bt Cotton Hybrids Evaluation Report – Central Zone (2006-07 ...

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Hybrids RCH 386 Bt and MRC 7351 BG II were superior in fibre length. Hybrid
KDCHH 621 BG II recorded the lowest fibre strength. Micronaire showed variation
across locations and RCH 138 Bt (Check) had the lowest Micronaire.
Nine Bt cotton hybrids were evaluated for two successive years during 2005-06
and 2006-07 in Central Zone. The hybrids were evaluated at five locations in Khandwa,
Surat, Akola, Nanded and Nagpur. The crop at Surat during the second year was affected
due to floods and was not taken for analysis.
Jassids, Thrips and Aphids were the main sucking pests. All the Bt hybrids
evaluated were susceptible to sucking pests at varying intensities and grades. Chemical
intervention was required to control them. The Bt hybrids showed minimum damage to
bollworm with reduced green boll and locule damage.
The onset and severity of the foliar disease varied both years. The Bt hybrids
have been found susceptible to these diseases. However, proper and timely plant
protection measures can reduce the damage to the crop.
In terms of mean seed cotton yield, under protected conditions, only two hybrids
viz., RCH 386 Bt and JKCH 99 BT were found to be superior to the check hybrids.
However, under unprotected conditions, apart from RCH 386 Bt, MRC 7351 BG II and
ACH 155-2 BG II were also superior to the check hybrids. Fibre quality wise the Bt test
hybrids were superior to the non Bt check hybrid NHH 44 and were on par with the Bt
check hybrids.
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