Effect of the Soil and Sawdust Substrates on the Sprouting Rates of Yam Minissetts Varieties in the Guinea Sudan Zone of Benin

Abstract

Yam (Dioscorea spp.) is a staple food for the Beninese population and is considered a food of great value. Despite its importance, production is limited by several factors, including the lack of planting material. In order to contribute to the sustainable production of yam plants, the technique of mini-fragmentation (minissett) was carried out as part of a land survey in the Guinea-Sudan zone in Benin. The objective of the study is to evaluate the effect of soil and sawdust substrates and interaction factors on sprouting rates of yam minissetts varieties. The experimental design consisted of a randomized complete block using a partial nested model with four factors (treatment, variety, repetition, year) conducted at the village level in the Akpéro and Gbanlin sites in central Benin. Substrate treatment varied between sites (sawdust (Sa) and sandy-clay (Scs) soil at Akpero, basket with sandy-clay soil (BScs) and basket with sawdust (BSa) at Gbanlin) according to smallholder farmers’ preference. For each treatment, early yam (Gangni, yanabo) and late maturing (kokoro) varieties were used replicated four times during the 2002-2003 and 2003-2004 seasons. Substrates of the basket were tested at Gbanlin by considering 5 alternating layers of mini-strata with sandy-clay soil or sawdust for the bed of the nursery. The healthy yam plants used ranged from 500 to 800 g, cut into 25-30 g portions with early and late maturing varieties of yams. The highest sprouting rates were significantly recorded in sandy-clay soils (no-basket). Treatment, Variety, Year and Treatment × Variety interactions were significant at the site.