SEEDLING EMERGENCE STABILITY OF BAMBARA GROUNDNUT [VIGNASUBTERRANEA L. (VERDC.)] UNDER SAVANNA AND HUMID RAIN FOREST AREAS CONDITIONS DURING TWO CROPPING SEASONS IN COTEDIVOIRE

The yield of Bambara groundnut [Vignasubterranea L. (Verdc.)] is extremely low and unpredictable. Erratic yields have been attributed, at least in part, to variable or poor field establishment due to seedling emergence. The aim of this study wasto evaluate under field conditions, the effects of genotype and environment on seedling emergence in Bambara groundnut. Field experiment was conducted with 15 landraces in Northern and Southern regions of Cote dIvoire. A randomized complete block design with five replications was used in each environment. Estimated variables included number of day for emergence (DFE), mean emergence time (MET), emergence index (EI), time to 50% emergence (T50) and seedling emergence percentage (EP). Analysis of variance revealed significant (P < 0.05) differences between genotypes, locations and the interaction genotype x location for all traits studied. Location x year x genotype interactions were only significant for DFE, EI and EP.The highest DFE and T50 and MET were observed with the genotype Ci7. The least DFE, MET and T50 were obtained with genotypes Ci1, Ci2, Ci10, Ci11, Ci12, Ci13 and Ci22. Highest seedling emergence percentage was recorded with genotype Ci15 (93.29%) in Korhogo and Ci4 in Korhogo (90.85%) and Abidjan (89.59 %). Lowest EP was observed with the genotype Ci3 (42.33%).Correlations indicated that genotype with higher emergence percentage, emerged faster (low DFE, MET, T50) and exhibited higher emergence index (EI). AMMI analysis showed that Ci1, Ci4, Ci7, Ci11, Ci14 and Ci15 were the ideal genotypes because they expressed high and stable EP.