Effect of propagule size and intra-row spacing on the growth and yield of sweetpotato in a humid agro-ecological zone

Abstract

A 4 x 3 factorial experiment with three replications was used to investigate the responses of sweetpotato to propagule size (1, 2, 3 and 4 node cuttings) and intra-row spacing (20, 30, and 40 cm) in 2003 and 2004 cropping season. The result showed that 3 and 4 node cutting had higher percentage (%) emergence at 2 weeks after planting (WAP) while % emergence of 1 and 2 node cuttings increased from 2 to 4 WAP. The number of roots per plant of all propagule sizes increased with age of plant but not beyond 11WAP while fresh root weight per plant consistently increased up to the time of harvest in most cases. Planting of higher propagule size at narrow spacing of 20cm depressed storage roots weight per plant. The graded number of storage root yield increased significantly (P 0.05) among average root yield of 17.9, 19.7 and 20.0 t/ha for 2, 3 and 4 node cuttings respectively compared to the yield of 13.4 t/ha recorded by 1-node cutting in both seasons. Planting of 2 node cuttings at narrower spacing of 20 cm on the average produced significantly more saleable and total storage root yield than when planted at wide spacing of 30 or 40 cm but the yield was not significantly different from the 3 or 4 node cuttings at various spacing in both seasons. The 2, 3 and 4 node cuttings produced similar yield and as such, number of nodes could be reduced to 2 to provide more plantable vine pieces in time of scarcity of planting material. Keywords: Sweetpotato, Ipomoea batatas , node cuttings, propagule size, intra-row spacing.