Evaluation of upland cotton (Gossypium hirsutum) genotypes suitable for machine picking

The experiment was conducted for five years 2007-2011 for evaluation of Non Bt and Bt varieties/genotypes. Twenty seven released/pre-released varieties (non-Bt) of Gossypium hirsutum L. were evaluated for 3 years from 2007 to 2009 and thirteen Bt cotton hybrids were also evaluated during 2010 and 2011 for their suitability to machine picking. The study suggested that Bt hybrids were better suited to machine picking than non Bt genotypes because of better synchronized maturity. Two non Bt genotypes RS 875 and F 2383 were found to be compact and early in maturity. However their seed cotton yield was significantly lower than other non Bt genotypes and Bt hybrids. Amongst Bt hybrids evaluated Masscot, Anlcur 2226, VBCH 1534, MRC 7031 and MRC 6304 were found to be high yielding and relatively better suited to machine picking. Defoliant "DROPP" was found to be effective when applied @ 5000ppm at 135 to 150 days after sowing or at 70% boll opening.