Some Morpho-Physiological Characteristics of Winter Wheat and Their Effects on Grain Yield

摘要

The grain yield of wheat is influenced by several morpho-physiological characteristics and also by developmental processes in the vegetation period. Five winter wheat genotypes (Yayla-305, Do?u-88, SXL/VEE "S", BEZ/CAL//BB, Turkey-13) were evaluated in respect to N doses (0, 40, 80, 120 kg/ha) and seeding rates (350, 475, 600 seed/m2) under the conditions present in Erzurum in the crop seasons of 1993-94 and 1994-95. A total of 29 characteristics were investigated and all the correlations between these characteristics were calculated. The effects of the 10 main characteristics on grain grain yield were investigated using path coefficient analysis and diagrams. Grain yield variations were mainly due to the number of kernels per spike and the number of spike per m2. Thousand kernel weight had a negligible effect on grain yield. An increase in the number of spike per m2 appeared to be accompanied by fewer kernels per spike and lighter kernels. These results indicate the existence of a dynamic balance in these characters. Thousand kernel weight was a function of grain-filling rate and green area duration. This study shows that future attempts to improve grain yield must focus on increasing the number of kernels per unit area rather than manipulating kernel weight.