Effect of Potassium on Tuber Yield and Yield Component of Potato (Solanium Tubersum ) on Loamy Soils of Atsbi-Wenberta, Tigray, Ethiopia

Abstract

An experiment was conducted to investigate the effect of different levels of potassium (K) fertilizer on the tuber yield and yield component of potato grown on loamy soils of Atsbi-Wenberta Wereda, Tigray, Ethiopia. The treatments were 0, 50, 100, and 150, kg/ ha K₂O. Nitrogen and phosphorus were applied at 110 N and 89.7 P₂O₅kg /ha, respectively to all plots. Potato variety Gudane was planted in with inter and intra row spacing of 70 cm and 30 cm, respectively. The experiment was laid out in RCB design with three replications. The result revealed that application of K has significantly increased, on days to flowering, average tuber weight, tuber diameter, and marketable and total tuber yield of potato compared with the control. The highest marketable (33.0t/ha) and total tuber yield (34.6t/ha) was obtained at K level applied at the rate of 100 kg /ha K₂O, it increased the total tuber yield from 27.26 t/ ha in the control to 34.6 t /ha. The highest total and marketable tuber yield increase by 29.2 and 26.92 %, respectively compared to the control was obtained due to K application at rates of 100 K₂O Kg/ha. Furthermore the partial budget analysis data showed that the highest net benefit and marginal rate of return (2450%) was obtained at K fertilizer application  rate  of 100 kg/ ha K₂O . It is concluded that application of K has   significant and positive response to tuber yield and yield component of potato in the study area, the highest biological and economic yield was obtained at K level of 100 kg /ha K₂O   indicating that soils of Atsbi-Wenberta area are deficient in K .Hence, it is recommended to apply K in the study area in order to attain optimum tuber yield, net income and return.

Keywords: Marketable yield, Potassium (K); Potato; tuber yield