The Influence of Genotype, and Harvesting Regime on Yield of Orange-Fleshed Sweet Potatoes and their Ranking by Farmers in Coastal Kenya

Abstract

A study was conducted in coastal Kenya in 2006 and 2007 to evaluate orange fleshed sweet potato (OFSP) genotypes for yield under different harvesting regimes. A randomized complete block design was used, with factorial arrangement of the treatments. Four OFSP genotypes (199034.1 (VI), 199027.3 (V2), 199026.1 (V3), and 199024.2 (V4) were evaluated alongside one local check {Mattawa 8 (V5)} under three harvesting regimes (three, four and five months after planting). The results indicated that the number of roots and the number of marketable roots per plant were higher (P ::; 0.05) for all the OFSP genotypes than for the check. The check was superior to all the test genotypes except V2 in terms of the proportion of marketable roots to the total number. Genotype VI showed higher vine yield than V5 (P:::: 0.05). Storage roots of the local check had higher percent dry matter than those of the OFSP genotypes (P :::: 0.05). Harvesting three months after planting gave lower number of storage roots (4.4) per plant than the 5-months harvesting regime (5.4) (P :::: 0.05). The harvesting regimes differed (P:::: 0.05) in their effect on the yield of storage roots. The ideal harvest time to for OFSP genotype V2 and the local check, was four months after planting. The most appropriate harvest time for the rest of the OFSP genotypes was five months after planting. Results of a farmers' evaluation showed that the farmers rated the local check highly in terms of percent dry matter, root shape and root flesh colour and root yield. There is need to educate farmers on the nutritional value of the OFSP varieties.