EFFECT OF TIME OF PLANTING AND HEAT STRESSES ON WHEAT ADVANCED GENOTYPES

Abstract

The studies were conducted to determine the effects of time of sowing and heat stresses
on yield and yield associated traits of wheat genotypes. Twenty advanced wheat genotypes
including a local check variety Sarsabz were screened at two sowing dates viz., normal sowing
(9th November) and late sowing (12th December) at Experimental Farm, NIA, Tando Jam. Data
on different yield and yield contributing traits were recorded and statistically analyzed. The
highly significant effects of heat stresses (between 330C to 430C) were observed during grain
filling periods, which affected the plant height, 1000-grain weight and grain yield, except days to
heading. Delayed planting adversely affected the yield and yield components of wheat
genotypes. All the genotypes produced significantly higher grain yield at normal sowing time
than late sown as compared using t-statistic. Twelve genotypes produced higher grain yield
(more than 4000 kg/ha) than check variety Sarsabz at normal sowing, while four genotypes viz.,
V-7005, SI-91195, PR-70 and 97B2210 produced higher grain yield than Sarsabz under late
planting, others were either inferior or at par with Sarsabz.