Effect of Intra-row Spacing on Growth and Yield of Irish Potato (Solanum tuberosum L. cv. Mondial) Grown in a Sub-tropical Environment of Eswatini

Abstract

Irish potato yields vary widely, usually showing a declining trend, due to differences in in-row spacing used, as well as poor varietal selection for specific locations. In this study the growth and yield responses to different intra-row spacing on Irish potato cultivar Mondial was evaluated. The treatments consisted of four intra-rows spacing namely: 15 cm, 30 cm, 45 cm and 60 cm. Inter-row spacing was maintained at 90 cm for all treatments. Treatments were arranged in a Randomized Complete Block Design (RCBD) and replicated four times. Measurements were taken on plant height, number of potato tubers per plant, leaf length and width and fresh weight of potato tubers. In-row spacing were significantly different at P <0.05 with 15 cm producing the highest mean height (26.90 cm) at 14 weeks after planting. The number of stems per plant were not significantly influenced (P>0.05) by the intrarow spacing. The highest number of main stems (6) was JOURNAL OF AGRICULTURE AND SUSTAINABILITY 2 recorded at 45 cm spacing and the lowest (5) at 15 cm spacing. The number of tubers per plant were not significantly different (P>0.05) in all the intra row spacing, and 15 cm intra row spacing had the highest number of tubers. There were significant (P<0.05) differences among the different intra row spacing for yield per plot. The highest yield (6.71 t/ha) was at the 60 cm spacing and the lowest (4.87 t/ha) was at the 15cm spacing in terms of size and marketability of the tubers. Based on the findings of the study it can be concluded that intra row spacing can be chosen according to the farmer’s desired size of tuber: that is to say as the intra row spacing decreases there is also a decrease in the size of tuber produced and vice versa. These results have shown that Irish potato (cultivar Mondial) grown at the 60 cm x 90 cm intra row spacing gave the best yield results and economic yields.