Evaluation of potato (Solanum tuberosum L) genotypes for yield and agronomic traits under irrigation in southern Tigray, Ethiopia

Abstract

Potato (Solanum tuberosum L.) is most important food crop in Ethiopia, and understanding its genetic variability is crucial for improvement efforts. However, research evaluating genotypes for yield and agronomic traits under irrigation in specific regions remains limited. This study aimed to assess the performance of 15 potato genotypes across 16 quantitative traits under irrigated conditions in Maichew and Emba-Alaje woredas during the 2024/2025. Randomized Complete Block design, with three replications was employed, utilizing plots of 3m x 3m with a spacing of 75 cm between rows and 30 cm between plants. Significant interaction effect was observed among the genotypes for most traits. The highest total tuber yields were recorded for G12 CIP302498.72 (48.94 t ha-1), G3 CIP397029.21 (48.71 t ha-1) and G2 CIP312923.637 (48.49 t ha-1) at Maichew while the lowest yield was noted for G13 CIP312920.599 (14.27 t ha-1) at Emba Alaje. Correlation analysis revealed positive associations between total tuber yield and Plant height (r=0.43), marketable tuber yield (r=0.99), unmarketable tuber number per hill (r=0.34), marketable tuber number per hill (r=0.68) and total tuber number per hill (r=0.58). Conversely, a negative correlation was observed with days to maturity (r= -0.47). Principal component analysis results revealed that the first three components accounted for 75.09% of the total variability (PC1:37.16%, PC2:23.98%, PC3:13.98%). Hierarchical clustering grouped the genotypes into five distinct clusters based on yield and quality traits. These findings highlight significant genetic variability among the evaluated potato genotypes. Given that the study was conducted over a single growing season at two locations, further research involving multiple seasons and locations is recommended to validate these results and assess factors such as late blight resistance in the southern zone of Tigray and similar agro-ecological areas.