ABSTRACT

Yield has been the major factor determining the level of production and consumption of African yam bean in Nigeria. Fifteen different accessions of the African yam bean (sphenostylls stenocarpa. Hochst ex A rich) Harms were screened for yield and yield association traits in field experience conducted at the Michael Okpara University of Agriculture Umudike experimental farm. The accessions of the African yam bean were laid out in a Randomized Complete Block Design with three replicates during the 2003 planting season and data were collected on the following attributes: leaf area, pod, weight, number of flowers per plant, days to flowering, grain filling period, days to physiological maturity, 100 seed weight, number of pods per plant, number of seeds per pod, tuber yield per plant, seed yield per pod, number of seeds per plant and seed yield per plant. Analysis of variance showed a highly significant difference among the accessions for few of the attributes investigated viz: leaf area (p<0.01), pod length (p<0.001), pod weight (p<0.01), seeds per pod (p<0.05), seed yield per pod (p<001) and 100 seed weight (p<0.05). The phenotypic and the genetic variances were quite low for all the attributes. Generally, heritability estimates in the broad sense were low for the attributes. Seed yield per plant was positively and significantly associated with pod weight, leaf area, number of flowers per plants, 100 seed weight, pods per plant, seeds per pod, seed yield per pod and seeds per plant (p<0.001). The implication of this result is discussed in terms of improvement in this very important pulse.