Author(s):
Potato is a vital food for human consumption, with a near optimal nutritional balance. However, the crop's quality is hampered by a variety of issues, the most serious of which is the limited availability of Potassium (K) and Phosphorus (P) in soils. The trial was carried out at Assosa to assess the influence of P and K fertilization on the quality of potato tubers. The treatments included four potassium levels (0, 100, 200 and 300 kg K2O ha-1) and six phosphorus levels (0, 100, 200 and 300 kg K2O ha-1) (46, 92, 138, 184 and 230 kg P2O5 ha-1). The experiment was set up as a factorial Randomized Block Design (RCBD) and duplicated three times. The result revealed that increasing the phosphorus level from 0 kg to 92 kg P2O5 ha-1 increased the mean tuber weight by approximately 26% over the zero phosphorus condition while increasing the potassium rate from 0 to 100 kg K2O ha-1 increased the average tuber weight by nearly 18%. The tuber specific gravity decreased when the mineral fertilizer rate was increased from 100 kg to 200 kg K2O ha-1. The potato tuber with the highest protein and starch content was obtained from the control and 100 kg K2O ha-1, respectively. Increasing potassium from 0 kg to 100 kg K2O ha-1 increased medium and large sized tuber production by approximately 34% and 91%, respectively. Raising the phosphorus rate increased small sized tuber yield significantly across all potash rates; however, increasing potash had a less pronounced effect on small sized tuber production across all phosphorus rates.
