Genotypic Variations in Quality and Shelf-Life of Fresh Roots of Philippine Sweet Potato Grown in Two Planting Seasons

Abstract

Sweet potato breeding in the Philippines has recently integrated root quality and shelf-life attributes in varietal development. In this study, the harvest and post-harvest quality of the fleshy roots of different sweet potato genotypes were determined. These genotypes included the existing recommended varieties and the elite selections from the polycross breeding nursery and were grown during the dry and wet planting seasons. Dry matter, starch, sugar and protein contents of freshly harvested roots were found to differ widely with genotype. During storage at ambient temperatures, starch content decreased, sugar content increased and in some genotypes dry matter increased. Protein content of the stored roots varied only slightly from that of fresh roots. The different genotypes also differed in the degree of weight loss, shrivelling, decay and consequently, shelf-life. Some genotypes had short-lived roots (less than 1 month) while others had roots which were still marketable at the end of the 3-month storage period. Root quality and shelf-life similarly varied with planting season. Some genotypes had increased dry matter, starch and sugar contents and long shelf-life when planted in the dry season while others had these characteristics when produced in the wet months. Protein content generally decreased in wet-season-produced roots. However, a number of genotypes had comparable root quality and shelf-life regardless of planting season.