Yield response of Bambara groundnut to plant population and seedbed type

(22 April, 2001; accepted 16 October, 2001) Abstract A field experiment to study the effect of plant population and seedbed type on yields of bambara groundnuts was conducted at Morogoro in Tanzania. The experiment was designed with three seedbed types split-plot; flat, ridge and furrow in the main plots and bambara groundnut population densities (9, 13, 22 and 66 plants m-2) in the sub plots. At 63 days after sowing (DAS), leaf area index (LAI) was highest for 66 plants m-2 and/or when planted on the ridge. In the short rain season, bambara groundnuts planted in the furrow at 13 plants m-2 had the highest (P< 0.05) grain yields (519.2 kg ha-1) and harvest index (62.5). Shelling percentage values were highest across all seedbed types (average 74.2%) at 13 plants m-2. In the long rains, LAI was also the highest (P< 0.05) for 66 plants m-2 at 63 DAS, but differences in LAI between seedbed types were not significant. Crop performance at 22 plants m-2 on a flat seedbed, earthed at weeding, was generally superior as it gave the highest (P< 0.05) pod yield (798 kg ha-1), grain yield (585.1 kg ha-1), and harvest index (75.0). In both the short and long rainy seasons, yields were significantly reduced to the lowest level at 66 plants m-2 regardless of the seedbed type. Key Words: Harvest index, leaf area index, population density, seedbed, Tanzania, Vigna subterranea Résumé Une expérience de terrain pour étudier les effets de la population des plantes et le type de semis sur le rendement de l'arachide bambara était conduite à Morogoro en Tanzanie. Les expériences étaient préparées sur trois types de semis: split-plot; plat, billons et sillons dans la parcelle principale et l'arachide bambara de densité (9, 13, 22 et 66 plantes m-2) dans les parcelles secondaires. Soixante et trois jours après la semence, l'indice de surface foliaire (LAI) était le plus élévé pour 66 plantes m-2 et / ou pour les plantes sur des stries. Durant la courte saison pluvieuse, l'arachide de bambara plantée sur les sillons à densité de 13 plantes m-2 avait le rendement le plus élévé de 519.2 kg ha-1 (