The wheat cultivars grown under elevated temperature of 3.5°C showed significant increase in average leaf area (LA), leaf area per shoot, leaf weight ratio (LWR) and leaf length, whereas it reduced the specific leaf weight (SLW), leaf width, plant height, total dry weight and days to flowering and maturity of wheat cultivars. The mean grain yield declined by 36% under warmer condition, which was attributed to maximum reduction in biological yield (35%) followed by grain growth rate per spike (24%), number of grains/spike (20%), number of spikes/pot (12%), 1000 grain weight (4%) and harvest index. The biological and economic yields of wheat were reduced at the rate of about 10% per°C increase in temperature. Amongst the cultivars, C 306, K 68, Kundan, HD 2329 and HD 2687 manifested higher productivity under warmer condition. High temperature also increased nitrogen content both in leaf and stem at flowering and maturity as well. However, the content of total sugar reduced drastically in shoots both at flowering and maturity stages. The starch content, however, increased markedly in leaf both at flowering and maturity.
Biological yield, harvest index, heat stress, leaf weight ratio, specific leaf weight
