Mineral Composition of Leaves and Tubers of Potato (Solanum tuberosum L.) Plants Cultivated in the Eastern Highlands of Ethiopia

Abstract

The problem of low yield and quality of potato in Ethiopia is attributable to nutrient deficiencies. Therefore, a survey was conducted to elucidate the problem through plant tissue analyses. Mature and fully expanded potato leaves and tubers were sampled randomly from purposively selected smallholder potato farms across seven villages in the eastern highlands of the country. The leaves were analysed for both macro- and micronutrients and the tubers were analysed for selected macronutrients. The data were subjected to analysis of variance, and explored with descriptive statistics. Ranges of leaf and tuber mineral concentrations were compared with deficiency, sufficiency, and excess ranges published for the crop. Leaf and tuber concentrations of the selected macronutrients were subjected to a correlation analysis. The results revealed that leaves sampled from four out of seven villages were deficient in nitrogen and phosphorus. Leaves from all villages were sufficient in all other macronutrients. Similarly, tubers sampled from five out of seven villages and those from three out of seven villages were deficient in nitrogen and phosphorus, respectively. Tubers from all villages were sufficient in potassium, calcium, and magnesium. Leaf micronutrient deficiencies were detected only for iron and manganese in two villages. Leaf and tuber concentrations of most mineral nutrients varied significantly across the villages, and some correlated positively. In conclusion, potato plants in the surveyed farms suffered mainly from nitrogen and phosphorus deficiencies, followed by deficiencies of iron and manganese.

Keywords: Deficiency; Leaves; Nutrient Concentration; Sufficiency; Tubers