Growth, Yield, and Water Productivity of Potato Genotypes Under Supplemental and Non-Supplemental Irrigation in Semi-Arid Areas of Northern Ethiopia

Potato is the dominant tuber and root crop grown in Tigray. However, the productivity is very low due to moisture stress, traditional production techniques, and low-yielding varieties. Hence, this study aimed to optimize potato yield by selecting suitable genotypes under both supplemental and non-supplemental irrigation conditions. The study involved five potato genotypes and two irrigation levels used as treatments arranged in a split plot using a randomized complete block design with three replications. Results revealed a significant difference in days to flowering and maturity, marketable and total tuber yield, and water productivity due to the main and interaction effect of genotype and irrigation. CIP-3960478.90 recorded significantly higher marketable yield (27.13 t ha−1), total tuber yield (28.71 t ha−1), and water productivity (7.59 kg m−3) under supplemental irrigation. Genotype CIP-394611.112 had achieved high marketable yield (24.45 t/ha), total yield (25.60 t/ha) and total water productivity (8.51 kg m−3) under non-irrigated treatment. Additionally, the potato water requirements in September and October exceeded the rainfall amounts, suggesting that supplemental irrigation is necessary during this period for optimal yields. Likewise, genotypes CIP-394611.112 and CIP-3960478.90, are recommended for semi-arid areas to enhance tuber yield with or without irrigation.