Optimum in-row distances for potato minituber production

Abstract

Two field trials were conducted in the Dominican Republic to determine the influence of in-row distances on 'Granola' potato (Solanum tuberosum) minituber yield and economic returns. Seedlings generated from in vitro microtubers were transplanted in open-field raised beds at in-row distances of 0.20, 0.25, 0.30, 0.35, and 0.40 m to compare their minituber yield. In-row distances affected potato minituber weight and number per hectare and per plant. Increasing in-row distances from 0.20 to 0.40 m produced a significant decline on minituber weight per hectare (from 12.6 to 8.7 t·ha-1, respectively). Minituber weight per plant increased linearly with in-row distances, improving from 195 g/plant at 0.20 m to 269 g/plant at 0.40 m. Minituber number per hectare declined linearly as inrow distances increased from 0.20 to 0.40 m, with values ranging between 425,000 and 119,000 minitubers/ha. Maximum values for the number of minitubers per plant were found with 0.20 and 0.25 m, with an average of 6.5 minitubers/plant. However, as distances between plants increased to 0.30 m or farther, the average values decreased to 5 minitubers/plant or less. The results demonstrated that the in-row distances of 0.20 and 0.25 m between plants were the most appropriate from the horticultural standpoint. However, the partial budget analysis reflected that the 0.25 m spacing had the highest marginal return rate among the treatments.