This research was carried out to assess yield and agronomic and physiological parameters of barley genotypes under rainfed conditions. The experiments were set up with 25 barley genotypes in a completely randomized blocks design with four replications during the 2017-2018 growing cycle at two locations in Edirne and Tekirdağ in the Trakia region, Turkey. Grain yield, plant height, days of heading, peduncle length, spike length, spike number per square meter, kernel number per spike, spike weight, flag leaf area, NDVI, canopy temperature, chlorophyll content, 1000-kernel weight, test weight, protein ratio, grain uniformity were investigated. The results of the study showed that there were significant differences among genotypes based on investigated characters. The highest grain yield (8509 kg ha-1) was computed for the G22 line. Grain yield was positively slightly correlated with spike weight, kernel number per spike, NDVI (Z55), 1000-kernel weight, test weight, and grain uniformity but no correlated with flag leaf area. There was a significant positive relation with spike weight and flag leaf area, spike length and kernel number per spike. Flag leaf area positively significantly correlated with kernel number per spike, and slightly positively correlated with spike length. Biomass (NDVI) at Z55 growth stage had a positive direct effect on grain yield, spike weight, peduncle length, spike number per square meter, 1000-kernel weight, test weight, protein ratio and grain uniformity. A negative correlation was observed between canopy temperature with grain yield, spike number per square meter, plant height, biomass (at Z55), 1000-kernel weight, test weight, protein ratio and grain uniformity. Therefore, biomass and canopy temperature would be important selection criteria for improved grain yield and yield components in the breeding material studied
