Crop phenology, thermal requirement, yield and fiber properties of cotton (Gossypium hirsutum) genotypes as influenced by different environments

Abstract

A field experiment was conducted during 2012-2013, and 2013-2014 with two dates of sowing as main plot and six genotypes as sub-plot treatments. Late sowing resulted in significant reduction in the days to 50 % flowering, days to 50 % boll bursting and days to maturity as well as number of GDDs for boll bursting and maturity compared to normal sowing. The fiber quality parameters, viz., 2.5 % span length, uniformity ratio, micronaire value, fiber strength, elongation and fiber maturity exhibited sig- nificant decline under late sowing. However, short fiber index increased under late sowing. Late sown crop could not develop a full canopy surface area as evidenced by reduced plant height, sympodia, leaf area and LAI at dif- ferent growth stages. The Bt hybrid, Ankur-3028 BG-II recorded significantly higher plant height, sympodia, number of bolls, boll weight, seed cotton yield, seed and lint index and fiber properties like 2.5 % span length, fiber strength. The Bt hybrid G.Cot.Hy.-8 BG-II was early in terms of days to 50 % squaring, flowering, boll bursting and maturity and required less GDDs to attain a particular growth stage. The genotype Ankur-3028 BG-II took sig- nificantly higher number of GDDs during flowering to boll opening stage.