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The economic potential of African leafy vegetables (ALVs) remains obscured by a poorly developed value chain. This scoping review assembled and examined scattered knowledge generated on ALVs across southern Africa, focusing on production, processing, marketing, and consumption. Two electronic databases (Scopus and Web of Science) were screened, and a total of 71 relevant studies were included and evaluated. The review provides a state of the art on knowledge related to utilisation of ALVs across the entire value chain. The findings show that functional properties are of prime importance in the production and consumption of ALVs. However, the lack of improved germplasm and a non-existent seed supply system are significant production bottlenecks. Pests and diseases affecting the productivity of ALVs remain mostly unexplored. Sun-drying and boiling were the most reported post-harvest processing methods, suggesting that traditional processing methods are still prominent. Many studies also confirmed the predominance of informal marketsin the trading of ALVs as they fail to penetrate formal markets because of poor product positioning and exclusion from produce demand and supply forecasts. The inception of cultivar development,mechanised processing methods, and market linkages will enhance the profitability of ALVs in the region. This review enhances the gaining of insight into the state of different value chain componentswill assist in upscaling production, value addition of products, and enhance marketing efficiency. There is a great opportunity for basic and applied research into ALVs.

Main conclusion Bambara groundnut has the potential to be used to contribute more the climate change ready agriculture. The requirement for nitrogen fixing, stress tolerant legumes is clear, particularly in low input agriculture. However, ensuring that existing negative traits are tackled and demand is stimulated through the development of markets and products still represents a challenge to making greater use of this legume. Abstract World agriculture is currently based on very limited numbers of crops, representing a significant risk to food supplies, particularly in the face of climate change which is expected to increase the frequency of extreme events. Minor and underutilised crops can help to develop a more resilient and nutritionally dense future agriculture. Bambara groundnut [Vigna subterranea (L.) Verdc.[, as a drought resistant, nitrogen-fixing, legume has a role to play. However, as with most underutilised crops, there are significant gaps in knowledge and also negative traits such as 'hard-to-cook' and 'photoperiod sensitivity to pod filling' associated with the crop which future breeding programmes and processing methods need to tackle, to allow it to make a significant contribution to the well-being of future generations. The current review assesses these factors and also considers what are the next steps towards realising the potential of this crop.

Seed storage proteins are mobilised during germination, especially at radicle protrusion. The objective of this study was to examine changes in protein expression during germination of Cleome gynandra in the presence or absence of light and at constant or alternating temperatures. Seeds were germinated at alternating 30/20 or 20oC in darkness and in continuous white light. Four prominent proteins of 28 - 32 kDa and 18 - 20 kDa, and a fifth low molecular weight protein of 13 kDa were observed in seedsharvested at brown pod maturity. These proteins remained unchanged during photoinhibition as shown on SDS-PAGE gels. Photoinhibition is a pseudodormancy condition during which seed storage proteins are not utilised.

As a leafy vegetable, Amaranthus can be harvested at different stages of plant growth, ranging from young seedlings to the late juvenile stage, but data on the changes in leaf nutritional value with plant age are scanty. The objective of this study was to determine the effect of growth temperature on Amaranthus leaf yield and nutritional quality at different stages of plant growth. Five species, A. hybridus var. cruentus, A. hypochondriacus, A. tricolor, A. thunbergii and A. hybridus were compared for their response to hot (33/27oC), warm (27/21oC) and cool (21/15oC) temperature regimes (day/night) in separate glasshouses. Plants were harvested at 20, 40 and 60 d after sowing and leaf yield, minerals (Ca, P and Fe), total protein content, amino acid (methionine and lysine) content and antioxidant activity (inhibition of linoleic acid oxidation) were determined. Seed yield and germination capacity, during two years of after-ripening, were also determined. Results showed that leaf protein content differed significantly (P < 0.01) between species. It was also significantly (P < 0.01) influenced by the growth temperature and stage of plant growth. The pattern of changes in the amounts of lysine and methionine was comparable to that of protein content, but A. thunbergii showed significantly higher amino acid content than the other species. Amaranthus leaves also contained significantly (P < 0.01) more lysine than methionine, regardless of the species and growth temperature. The phosphorus content of leaves was not significantly affected by temperature and stage of plant development, and there were also no significant differences between species. However, the amounts of both calcium and iron changed significantly (P < 0.05) with stages of plant development and with increasing temperatures for all species. The antioxidant activity of Amaranthus leaves increased consistently with plant age and there were significant (P < 0.01) differences between stages of plant development and growth temperature. Warm temperature regimes were most favourable (P < 0.01) for biomass accumulation in all species. Seed production under cool and hot temperatures significantly (P < 0.01) decreased seed germination capacity for all species, but germination improved in response to after-ripening. It is recommended that for greater nutritional benefit, Amaranthus should be grown under warm conditions and younger leaves are preferable.Keywords: Amaranthus, leaf nutrients, plant age, temperature