Effect of Inter and Intra Row Spacing on Tuber Yield and Yield Components of Potato (Solanum tuberosum L.) in Guji zone, Southern Ethiopia

Potato (Solanum tuberosum L.) production plays an important role in improving household income and nutrition and thereby contributes to food security. Despite of this, the current productivity of the crop is below the potential. The major production problems of potato take into account that low tuber yield are unavailability and high cost of seed tubers, lack of well adapted cultivars, poor agronomic practices, diseases, insect pests, inadequate storage, transportation and marketing facilities. The experiment was conducted at Bore Agricultural Research center at Bore on station and Ana sora district on-farm during the period from April 2014 to September 2016 copping season with the aim to determine appropriate plant population per unit area to obtain high yield, quality tuber size and to evaluate the best economic return of inter and intra row spacing for potato production in area. The experiment was arranged in factorial RCBD with three replications. Treatments consisted of factorial combinations of four levels of inter row (70, 75, 80 and 85 cm) and four levels of intra row (20, 30, 40 and 50 cm) spacing. Data days to 50% emergence, 50% flowering and 90% maturity, plant height (cm), number of main stem, and average tuber number per hill, average tuber weight (gm) and marketable, unmarketable and total tuber yield (t ha-1) data were collected and analyzed by using SAS software computer. The ANOVA results revealed that both main and interaction effects of inter and intra row spacing not significantly (P < 0.05) influenced on days to 50% emergence, 50% flowering, and 90% maturity for both location and main stem number for bore location. However, the ANOVA results revealed that the main and interaction effect of inter and intra row spacing was significantly (P < 0.05) influenced plant height (cm), number of main stem, average tuber number per hill, average tuber weight, marketable and unmarketable tuber yield and total tuber yield due to the treatments. The maximum marketable tuber yield (42.57 t ha-1) and (41.61 t ha-1) for Bore and Ana sora site respectively obtained from 75 cm inter and 30 cm intra row spacing statistically at par with the control yield (20.55 and 19.91 t ha-1) and treatment employed on maximum spacing (85*50 cm) which yielded 23.05 and 18.85 t ha-1 at Bore and Ana sora respectively. The marginal rates of returns, which determine the acceptability of any treatment, show that treatment that plants planted in a spacing of 75*30 cm yielded good results with 2087.61% marginal revenue. The results of the study suggested that Belete potato variety responded well to the combined application use of Inter and Intra row spacing. Therefore, potato growers in the study area can benefit if they use 75*30 cm inter and intra-row spacing.”