Influence of Sowing Date on the Growth and Yield of Bambara Groundnut Landraces in Tanzania

Abstract

Sequential sowings were carried out at Dodoma, Tanzania, to examine the eect of changing climatic parameters on the growth and yield of bambara groundnut (Vigna subterranea). Rainfall during the crop life cycle varied from 163 to 611 mm, mean photoperiod from 11.82 to 12.09 h d 71 and mean temperature from 22.6 to 24.4 8C. In 1994, the highest pod yields were achieved at the earliest sowing date, with a maximum of 2.87 and 1.42 t ha 71 for the red-and cream-seeded landraces, representing pod harvest indices of 0.56 and 0.34 respectively. A 30-d delay in sowing caused 460% reduction in pod yield, and a further 30-d delay resulted in no pods at all. Similarly, in 1995 successive delays in sowing caused dramatic yield declines, and the maximum yield was much lower, at 0.44 t ha 71 . In 1996 there was no signi®cant dierence in pod yields between the two early sowing dates for the red-seeded landrace and yields were again lower than in 1994 with a maximum of 1.02 t ha 71 . Dierences in dry matter production between sowings and years were attributed mainly to dierences in the amount and distribution of rainfall and to declining temperatures towards the end of the season; however, partitioning to pods was remarkably consistent across sowings.

Evaluation of Bambara groundnut varieties for off-season production in Zimbabwe

“…This suggests that they might have been tolerant to low ambient soil temperatures. The observed yields are comparable to the 3.0 t ha -1 reported for landraces in Tanzania (Collinson et al, 2000) and for experimental entries in South Africa (Swanevelder, 1998). Chipofu, Tulimara-S2, 3806/ 90, IND-1, BS544, BS545, Ndebvu, and BS28 took the shortest time (Table 1) to reach 95% physiological maturity, indicating that they are early maturing; while the rest could be classified as intermediate to late maturing.…”

“…Although there was lack of balance between the entries in the two groups, this preliminary observation suggests that high yield potential is strongly associated with long pod filling period in bambara groundnut and that selection for yield increased maturing period of the improved varieties. Overall, the yields observed in this study were comparable to those in-season yields in Zimbabwe (Madamba, 1995), Tanzania (Collinson et al, 2000) and South Africa (Swanevelder, 1998). There is, therefore, potential for off-season cultivar development from the current germplasm.…”

“…Madamba (1995) reported yield of 0.3 t ha -1 under marginal conditions and up to 4.2 t ha -1 with improved cultivars under optimum conditions. This was comparable to ranges of 3.0 t ha -1 reported for landrace in Tanzania (Collinson et al, 2000) and South Africa (Swanevelder, 1998). Landrace varieties still dominate the area under bambara groundnut production in southern Africa, which is a clear indication that limited breeding efforts have been put on the crop.…”

“…The days to maturity were more than the in-season times of 102 -115 days reported in Zimbabwe by Chibudu (1995), but the OP (Fig. 1d) was comparable to the 111 -134 days and 110 -150 days ranges reported for Tanzania and South Africa by Collinson et al (2000) and Swanevelder (1998), respectively. However, there were similar (P>0.05) days to 50% flowering (Fig.…”

In vitro culture of Bambara groundnut [<i>Vigna subrerranea</i> (L.) Verdc., Favaceae ]: Effect of plant growth regulators, explant type and genotype on callus induction and differentiation

“…The seeds can be eaten fresh (when semi-ripe), as a pulse (when dry and mature) or they can be ground into flour (Linnemann and Azam-Ali, 1993). Bambara plays an important role in food security, particularly in terms of protein requirements for low-income farmers (Collinson et al, 2000). The seeds are used also as feed for pigs and poultry and the haulm as fodder (Doku and Karikari, 1971).…”