Genotype Responses of Barley for Crop Adaptability, Yield Variations and Quality Traits under Terminal Heat Stress Conditions

Abstract

Genotype Responses of Barley for Crop Adaptability, Yield Variations and Quality Traits under Terminal Heat Stress Conditions. Int. J. Agric. Nat. Resour. 148-163. Barley, a vital crop globally, faces increasing threats from rising temperatures and climate variability. The physiological and morphological characteristics of ten advanced barley lines and two cultivars were assessed in this study over a two-year period under rain-fed conditions. This research revealed significant variations in genotype performance under terminal heat stress. The results highlight that temperature stress exceeded critical thresholds during critical growth stages, impacting grain yield and quality. Genotypes such as 'IBON HI 16-12' displayed consistently high yields, whereas 'Kendal' showed adaptability across varying conditions. The leaf chlorophyll content (SPAD) and normalized difference vegetation index (NDVI) varied among the genotypes, and a high NDVI did not consistently lead to higher yields under heat stress conditions. Quality traits, including protein content, test weight, and thousand-kernel weight, fluctuated independently of yield. Canopeo measurements highlight rapid ground cover growth, emphasizing its importance for plant productivity. Genotypes with delayed heading and prolonged physiological maturity presented high yields under heat stress. Leaf area index (LAI) measurements may aid in the selection of heat-tolerant genotypes. Alternatively, Canopeo measurements at 85-95% coverage provide valuable data for assessing genotype performance. This study enhances our understanding of barley's response to heat stress, emphasizing genotype adaptability and the need for further research to address temperature-related yield variations.