Physiological analysis of growth and productivity in wheat cultivars

Fifteen promising wheat cultivars developed between sixties and nineties in India were evaluated for their morpho-physiological traits associated with growth and productivity. Among the cultivars of different stature and duration, semi-dwarf long duration cultivars, viz. Kalyansona, HD 2643, HD 2687, UP 2338 and PBW 343 recorded highest productivity followed by semi-dwarf short and medium duration cultivars namely Arjun, Moti, HD 2285, HD 2329, Pratap and Kundan, while tall and semi-tall cultivars (C 306, K 68 and Sonalika) manifested lowest grain yield. The maximum productivity in semi-dwarf long duration cultivars was attributed to marked increase in their biological yield, leaf area index, grains/spike, days to flowering and grain growth rate. The enhancement in productivity of semi-dwarf short and medium duration cultivars over tall and semi-tall cultivars was mainly attributed to marked improvement in their harvest index. However, lowest grain yield in tall and semi-tall cultivars was probably due to their poor leaf area index and harvest index. The net photosynthetic rate of flag leaf at flowering and post flowering stages and chlorophyll content did not show any relationship with grain yield in tested wheat cultivars. Thus, further improvement in biological yield without reduction in present level of harvest index (45–46%) either through greater leaf area duration or increased leaf photosynthetic activity may possibly result in further improvement of wheat productivity.