Optimization and Economic Perspective of Planting Density and Minituber Size in Potato Seed Production

Minitubers serve as an excellent starting material for disease-less and healthy Pre-Elite seed tuber production. Nevertheless, it requires an optimum choice of production technology due to the associated high costs. Optimization and economic study were carried out using three different minituber sizes and five in-row planting distances of two industrial potato genotypes (Lady Olympia “LO” and Russet Burbank “RBB”). Two years of field data on yield and yield-related traits showed that both genotypes performed better at 26 cm intra-row spacing with large minitubers (≥ 25.1 mm). Planting of ≥ 25.1 mm minitubers resulted in the highest average tuber yield in both genotypes at a narrow planting distance of 10 cm. Minitubers of 20.1–25.0 mm and ≤ 20.0 mm produced low tuber yield at any in-row planting distance since large minitubers possess a high amount of food and energy reserves, which made them suitable for commercial seed production. Regression studies revealed a sequential decrease in tuber yield with an increase in plant spacing irrespective of minituber size. Partial budget analysis suggested that large minitubers (≥ 25.1 mm) gave maximum net returns at 22 and 26 cm in LO, while an efficient intra-row distance in RBB was 18 cm. However, if RBB was sown with minitubers of 20.1–25.0 mm, it yielded the highest economic returns at wider plant spacings (22 and 26 cm). Minitubers of ≤ 20.0 mm generated minimum benefits due to the lowest tuber yield and less net economic returns. This study revealed the importance of optimization of plant density depending on minituber size and cultivars for pre-basic seed potato production.