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Bambara groundnut is vital for food security due to its high nutritional content and resilience to environmental stresses. The objectives of the study were to determine associations among agronomic traits and nutrients in Bambara groundnut and identify traits influencing grain production in Bambara groundnut. Field experiments were conducted at the University of KwaZulu-Natal's Ukulinga Farm and Controlled Environment Facility (CEF) to assess agronomic performance and nutritional content. Nutritional content was evaluated using standard combustion procedures and electron microscopy. Correlation, regression, and path coefficient analyses revealed varying relationships among agronomic traits, nutrient content, and grain yield. The number of seeds (NS), healthy seeds (NHS), and plant height (PH) exhibited significant associations with grain yield. Neutral detergent fiber (NDF), starch, magnesium (Mg), nitrogen (N), oxygen (O), and phosphorus (P), were the key predictors of grain yield productivity. Path coefficient analysis showed that NS, PH and magnesium, oxygen, and carbon contents positively affected grain yield. In conclusion, grain yield was influenced by multiple traits through different pathways that are complicated by the growing environment. Selecting taller genotypes with good agronomic traits and high nutrient content is recommended to develop high yielding Bambara groundnut cultivars. [ABSTRACT FROM AUTHOR]

Bottle gourd [Lagenaria siceraria(Molina) Standly] is a neglected underutilized species that is available only as a landrace in sub-Saharan Africa. The objective of this study was to evaluate responses of bottle gourd landraces to water stress compared with pumpkin (Cucurbita maxima) and cucumber (Cucurbita pepo), the closest relatives. For this purpose, two bottle gourd landraces and one green pumpkin cultivar and a cucumber cultivar were grown under controlled conditions at three levels of water stress. Landraces had longer vines than hybrids while hybrid varieties produced more leaves than landraces at all levels of water treatments. The responses of landraces and hybrids to water stress were similar in that they all showed lower chlorophyll content index, stomatal conductance and plant growth in response to decreasing water availability. However, the landraces showed better stomatal regulation indicating better acclimation to water stress. The comparable performance of landraces to the exotic pumpkin and cucumber varieties and their water stress tolerance suggests that bottle gourd could be promoted as an alternative food security crop in rural communities. [ABSTRACT FROM PUBLISHER]

Three sweet potato cultivars (A40, A45 and 199062.1) were planted in three small-scale farms located under different agro-ecological zones of KwaZulu-Natal. The objective was to assess growth, physiological responses and yield of the sweet potato cultivars under low-input agricultural system and different environmental conditions. Sweet potato planted at Richards Bay (28°19'S; 32°06E), a coastal sandy soil location, recorded low stomatal conductance(SC; 102.2 m moles m−2s−1) and chlorophyll content index (CCI; 29.4). This consequently resulted in reduced vine length, leaf number and branching of sweet potato plants. Environmental conditions in that location (Richards Bay) such as high evapotranspiration, high temperatures and low water retention capacity of sandy soils created drought stress condition. This caused reduction in photosynthetic activities and translocation to the harvestable plant parts. The other two locations (Deepdale at 28°01'S; 28°99'E and Umbumbulu at 29°98'S; 30°70'E) located further from the coast and characterized by clayey soils recorded higher SC and CCI. Branching and number of leaves were significantly influenced by locations and growing season while vine length varied with locations, indicating specific varietal adaptation. Biomass and storage root yield followed a similar trend as plant growth and physiology. Richards Bay recorded very low biomass and storage root yield (5.4 and 5.0 t ha−1) in both seasons while Deepdale recorded higher yields (42.0 t ha−1) during the first growing season. Yields reduced by 67% (13.6 t ha−1) in the second season. Storage root yields from Umbumbulu were stable in both growing seasons (29.4 and 28 t ha−1during seasons one and two, respectively). Adding fertilizer only improved storage roots yield in Richards Bay, otherwise cultural practises were responsible for storage root yield increases in Deepdale and Umbumbulu. Orange-fleshed sweet potato cultivar A45 showed good environmental plasticity while cultivar 199062.1 responded well to fertilizer application. This indicated its suitability for use in food security programmes under low-input agriculture. [ABSTRACT FROM PUBLISHER]