Barley (Hordeum vulgare L.) is a widely cultivated crop with significant economic and agricultural importance. This study aimed to evaluate the performance of four barley genotypes (Tarm 92, İnce, Ünver, and Burakbey) under irrigated, drought, and potassium iodide (PI)-induced drought stress conditions. Key yield components, quality traits, and biochemical responses were assessed. Statistical analyses, including ANOVA, PCA-Biplot, Decision Tree, and a Ridge Regression Artificial Intelligence Model, were used to determine the primary factors influencing seed yield. Results revealed that irrigation significantly increased yield-related traits, while drought stress led to higher protein content, micro-sedimentation, proline, and catalase activity, indicating stress adaptation mechanisms. PI application effectively simulated drought conditions, confirming its suitability for drought tolerance screening in breeding programs. Among genotypes, Tarm 92, İnce, and Ünver demonstrated superior yield, quality, and drought tolerance. Statistical analyses revealed that chlorophyll B, chlorophyll A, seed number per spike, seed weight per spike, and test weight were identified as the most influential factors affecting seed yield. These findings emphasize the importance of photosynthetic efficiency, biomass partitioning, and stress adaptation in enhancing barley productivity under different environmental conditions.
Okan Sezer (Tue,) studied this question.