Mkandawire, Frackson Lameck2026-08-142026-08-141996https://www.suaire.sua.ac.tz/handle/20.500.14820/7903DissertationA field experiment was laid out during the short (October to February) and long (March to June) rain seasons to evaluate the effects of population density and types of seedbed on the growth and grain yield of bambaranuts [Vigna subterranea (L.) Verde.). The experimental design was a split­ plot laid out in a randomized complete block with three replications. Types of seedbed (flat, ridge and furrow) were the main plot factors while population densities T, =■ (94 444), T2 - (133 333), T3 - (222 222) and T« - (666 666) plants ha'1 achieved by intra-row and inter-row spacings of 35 x 30, 25 x 30, 15 x 30 and 5 x 30 cm were sub plots, respectively. During both seasons, bambaranuts planted on the ridge across all population densities were slowest to emerge. Generally, emergence rates decreased with increase in plant population densities. During the short rain season, bambaranuts planted on the ridge were the tallest (38.2 cm) at 66 ' plants m'2, had the highest leaf area plant'1 (4460.6 cm2), highest leaf area index and highest root: shoot ratio at 9 plants m'2. Bambaranuts planted in the furrow had the highest number of flowers plant'1 (26.0) at 9 plants m'2, highest number of pegs plant'1 (57.8) and highest number of pods plant'1 (18.2 and 18.7) at 9 and 13 plants m'2, respectively. The crop planted in the furrow or ridge resulted into higher values for root dry matter plant'1 (6.7 g) at 13 plants m'2, number of plants at harvest (63), highest grain yield (519.2 kg ha'1 at 13 plants m'2 and highest harvest index (62.5) at 13 plants m'2. Bambaranuts recorded significantly (PX0.05) higher values for shelling percentage at 13 plants m'2 across all types of seedbed. During the long rain season, planting on the flat or in the furrow resulted into the tallest plants, highest leaf area plant'1 (1343.69) at 13 plants m' -2 2, highest shoot dry matter plant'1 (10.9 g and 10.1 g) at 13 and 22 plants m'2, respectively. The crop planted in the furrow resulted into the highest number of plants (66) at harvest at 66 plants m'2 and highest above ground dry matter (1271.6 kg ha'1) at 13 plants m'2. Bambaranuts planted on the ridge or flat recorded significantly (P<_0.05) high values for shelling percentage (85.5 and 80.6) at 22 plants m'2. The crop planted on the flat resulted into the highest number of flowers (31.6) and pegs (72.9) ijiant'1 at 22 plants m'2, highest number of pods (14.4 and 14.7) at 13 and 22 plants m'2, respectively, highest root dry matter (4.10) at 22 plants m'2, highest root : shoot ratio (0.45) at 22 plants m'2, highest pod yield (1065.3 kg ha'1), highest grain yield (746.6 kg ha'1) at 22 plants m'2, highest 100-seed weight (36.6 g) at 9 plants m'2 and highest harvest index (95.8) at 22 plants m'2. Generally, leaf area plant'1 for both seasons decreased with increase in population density while LAI increased. Flower, peg, pod, shoot and root dry matter decreased with increase in population density during the short rain season but were variable for the long rain season. Bambaranut yield was positively correlated with the number of flowers, pegs, pods, pod dry matter and kernel dry matter during the short rain season. Positive correlations for the number of pods, leaves, pod dry matter, kernel dry matter, stem dry matter with grain yield were also observed during the long rain season. On the basis of coefficient of determination (R2) values, pod dry matter, number of pods and kernel dry matter were the most important factors that determineenPlant densitySeedbed typesGrain yieldBambaranutsVigna subterraneaThesis