Effect of blended fertilizer rates and planting density on yield and yield components of Irish potato (Solanum tuberosum L.) at Gombora condition, Hadiya zone, Southern Ethiopia

Potato is an important food and cash crop and it has high yielding potential in many parts of Ethiopia; however the yield of the crop is often constrained due to low and imbalanced rates of inorganic fertilizers and inappropriate spacing. The field experiment was conducted to determine the effect of five rates of blended fertilizer (0, 100, 150, 200, and 250) kg NPS ha(−1) and intra-row planting spacing of 20 cm, 30 cm and 40 cm and laid out by randomized complete block design with three replication in a factorial arrangement. The analysis of variance revealed that, marketable tuber yield, total tuber yield, stem number per hill, total fresh mass, underground fresh and dry mass were significantly (P < 0.05) influenced by the interaction of Nitrogen, Phosphorous and Sulfur (NPS blended fertilizer) and intra-row spacing. The highest plant height (96.60 cm), highest marketable tuber yield (34.29 tha(-1)), highest total tuber yield (38.36 t ha(−1)) and highest total fresh biomass (1274.2 g plant(−1)) were recorded from NPS rate of 250 kg NPS ha(−1) and intra-row spacing of 20 cm while the lowest recorded from control treatment in wider intra-row spacing (40 cm). Therefore, the application of 250 kg NPS ha(−1) with the intra-row spacing of 20 cm can give an optimum tuber yield and it could be recommended for the production of potato in the study area.