PERFORMANCE OF WHEAT IN LATE PLANTING INDUCED HIGH TEMPERATURE STRESS

Abstract

An experiment was conducted at the Research farm and laboratory of Crop Physiology and Ecology Department, Hajee Mohammad Danesh Science and Technology University, Dinajpur during November 2011 to April 2012 to examine the effect of late sowing heat stress on performance of some wheat genotypes. The experiment was laid out in split plot design with three replications. Two sowing dates (November 30 and December 30) were considered as main plot treatments and four wheat genotypes (BAW 1051, BARI Gom 26, Bulbul and BARI Gom 25) were considered as sub plot treatments. BAW 1051, BARI Gom 26 and BARI Gom 25 provided greater maximum ear dry weight and longer grain growth duration under heat stress compared to Bulbul. In addition, these three wheat genotypes (BAW 1051, BARI Gom 26 and BARI Gom 25) showed greater ability to retain flag leaf chlorophyll, accumulate greater amount of proline in both flag leaf and kernel along with keep the canopy cooler compared to Bulbul. Late sowing induced ‘heat stress significantly reduced ears m”, grains ear’, spikelets ear’, 1000-seed weight, grain yield and straw yield but greater reduction of these parameters was found in Bulbul than the other genotypes e.g. in BAW 1051, BARI Gom-26 and BARI Gom-25. Finally, based on heat susceptibility index for grain yield, and praline content in both flag leaf and kernel Bulbul was most susceptible genotype and BARI Gom-26 was found as the most tolerant in view of praline accumulation in leaf and kernel.