Abstract:
Purpose : This study was conducted at Crop Physiology and Ecology Department. Hafer Mohammad Danesh Science and Technology Unimak): Dinajpur to identify, phenologn growing degree days, phenothermal index and heat use efficiency of wheat genotypes in response to heat stress. Research Method: Eight wheat genotypes viz.. Pawn-76. Prodip. BA R1 Crom-25. BA 11.1 Gom-26. BA1Y-1143. BAW-1146. BAN'-1147 and BAW-118 were used and seeding them at November 27 (normal), December 17 Rate) and January 7 (very late growing condition) over two successive years of 2011-12 and 2012-13. The experiment was laid out in a split plot design and main plot treatments were sowing time and sub plot design was wheat genotypes. Findings : The number of days for attaining different phenological stages. the requirement of heat unit (GOD). phenothermal index (PM and heat use efficiency (HUE) was higher for normal growing condition compared to late and very late growing condition and higher In heat tolerant genotypes than the heat sensitive genotypes in each sowings of every year The heat tolerant (HT) genotype BAW-1143 needed highest number of days whereas. HS genotype Pavan-76 required the lowest number of days for attaining all the phenological stages .Under normal growing condition. HT genotype VW -1143 had the significantly highest HUE (2.22 and 2.37 for first and second year• respectively). But HS genotype Pavan-76 had the lowest HUE (1.7! and 2.16 forfrst and second year. respectively). Limitations : The limitations of the research are apparent to the fact that it was done in a single location. Orkinalityablue : This research helps the researcher to identiffi heat tolerance genotypes for further investigation.
