Department of Plant Breeding & Genetics, Punjab Agricultural University, Ludhiana -141 004
A field experiment was laid out to study the effect of defoliant (ethrel) through foliar application on yield and fibre quality traits of a late maturing Bt cotton hybrid (RCH 134 Bt) during 2007 and 2008. No significant differences for seed cotton yield during 2007 were recorded when the ethrel was applied (500, 650 and 800 ppm) at 130 and 145 DAS. However, the treatments recorded, numerically, higher seed cotton yield than that of the control. Maximum increase of 12.5% in seed cotton yield was observed when ethrel was applied @ 800 ppm at 145 DAS. Maximum number of bolls per plant (68) with maximum boll opening percentage (80) was recorded in the same treatment. To further improve the boll opening percentage for better yield performance same experiment was conducted using higher doses of ethrel (1500, 2000 and 2500ppm) at 145 and 160 DAS during 2008. Of the various treatments, ethrel @ 2000 ppm at 145 and 160 DAS was found most effective in improving the boll opening percentage to get higher yield potential from the late maturing Bt hybrid without having any adverse affect on fibre quality traits.
Seed cotton yield, fibre quality traits, per cent boll opening, ethrel, Bt cotton
