Effect of Time of Planting and Age at Harvest on Marketable Yield and Quality of Four Tanier Cultivars

Abstract

An experiment was initiated in April 1972 at the Isabela Substation to evaluate the effect of season of planting and age at harvest on yield and tuber quality of four tanier cultivars. Bimonthly plantings were made from April 1972 to February 1973. Cultivar Kelly was harvested at 8 and 10 months of age, whereas Blanca del País, Morada, and Rascana were harvested at 10 and 12 months. The best planting dates appeared to be from April through August. A sharp reduction in marketable yield was evident for all cultivars planted after this period. For all planting dates the best yields were obtained when both Rascana and Morada were harvested at 12 months of age. Yields of Blanca del País, the standard tanier for the Isabela area, were inferior to those of the other cultivars with the excepton of Kelly. In general all cultivars were favored by the 2-month delay in harvest. However, Rascana was most favored by this delay, which significantly increased the number of marketable tubers. Planting dates and age at harvest had no effect on tuber internal quality. Although the delay in harvest somewhat softened the texture, cooked tubers were rated "acceptable" by a tasting panel.