Study of Grain Yield and Agro-Physiological Characteristics of Some Promising Rainfed Bread Wheat Genotypes under No-Till Condition

   In order to evaluate the productivity potential of some bread wheat varieties and promising lines under no-till rainfed condition two different on-farm trials were conducted in cold (Sonqor) and warm (Sarpol-e Zahab) regions of Kermanshah province during 2017-18 cropping season. In the cold condition, 12 winter genotypes and in the warm condition 32 spring genotypes were evaluated for grain yield and its components, morphological traits, canopy temperature, relative chlorophyll content (SPAD) and normalized difference vegetation index (NDVI). In the cold condition, the genotypes were significantly different for peduncle extrusion length, number of grain per spike, number of spike per m2 and thousand-kernel weight, peduncle length and gain yield. Grain yield of genotypes varied from 2849 (Sardari) to 4274 (G10) kgha-1 and four genotypes (G2, G4, G10 and G12) had higher yield than check variety (p < 0.05). In the warm condition, the genotypes were different for SPAD, plant height, peduncle extrusion length, peduncle length, 1000-kernel weight and days to heading. Grain yield of genotypes varied from 364 (G22) to 1363 (G8) kgha-1, and G8 and G10 were superior to the check variety (Aftab) by 89% and 61%, respectively. The profiles of trait associations were relatively different in cold and warm conditions. NDVI was positively correlated with grain yield, number of kernel per spike and 1000-kernel weight and negatively correlated with canopy temperature in the warm region. These results showing the importance of NDVI in identifying productive wheat genotypes for dryland conditions.