Wild vegetables (WV) are an important source of food in the maize based subsistence farming sector of rural South Africa. Their main role is as relish as they are used as an accompaniment for staple cereal based diets. They are generally reported to be rich in micronutrients. Although they may be consumed in small quantities, they influence the intake of cereal staples, manage hunger and play a central role in household food security for the poorer rural groups. Mixing several WV species in one meal contributes to dietary diversity in terms of more vegetable types as well as in terms of choice of relish. For some very poor families WV are substitutes for some food crops. The seasonal occurrence of these vegetables leaves many families without a food source during the off-season. Wild vegetables increase agro-biodiversity at the household level. This agro-biodiversity helps in buffering against the accumulation and multiplication of pests and diseases and provides important cover for the soil. Further research on agronomic, social and economic dimensions is required to understand the roles of WV in subsistence farming systems in South Africa.

Audouin, M., R. Preiser, S. Nienaber, L. Downsborough, J. Lanz, and S. Mavengahama. 2013. Exploring the implications of critical complexity for the study of social-ecological systems. Ecology and Society 18(3): 12. https://doi.org/10.5751/ES-05434-180312

Globally, food and nutritional state are marked by an acute prevalence of undernourishment, leading to malnutrition, starvation, and poverty. This state has remained vital for the past years, making attaining zero hunger for the anticipated period (2030) in Africa less possible. To alleviate this challenge, more sustainable food production systems, policy frameworks, mindset changes, and diversification of the food production systems must include some highly nutritious underutilized orphan crops. Acknowledging the potential of untapped, versatile, and climate resilience, Amaranthus significantly promotes sustainable and nutrient-rich food systems. Amaranth grain is a pseudocereal with 4 g of protein and 19 g of carbohydrates per 100 g of cooked amaranth. It is a nutrient powerhouse constituting valuable nutraceuticals, protein, and carbohydrates. Grain amaranth yield ranges from 1500 to 7200 kg/ha. Yield variableness of grain amaranth, lays openings for scientists and researchers to study crop improvement and access a rich pool of genetic materials. These attributes make Amaranthus (amaranth) the most suitable crop candidate in these climate change scenarios. The Amaranthus spp. are popularly known as weedy species and largely undomesticated crops with good adaptability to various geographical locations. Despite its good adaptability, it is less known, under-exploited, and less popular as human food, and its production is very scanty, especially in southern Africa. Efforts are needed to promote its adoption and commercialization. The authors searched pieces of literature in books, journals, and conference papers to establish the potential usage of Amaranthus, its nutritional composition, and its production practices.

Food security in sub–Saharan Africa is threatened by the increasing incidence of heat stress. Therefore, ameliorating heat stress influence in plants is vital for sustainable crop production. A 2 × 3 × 3 × 2 factorial experiment fitted into a completely randomized design with four replications was performed. The factors were heat stress, maize variety, soil amendment, and soil type. The results showed that heat stress exerted a depressive effect on maize growth and yield attributes. It reduced the leaf chlorophyll content, leaf area, plant height, stem diameter, dry biomass yield, and harvest index by 35%, 36%, 41%, 59%, and 78%, respectively. Sandy clay loam soil provided a better maize growth condition than loamy sand soil. Organic manure soil amendment improved maize growth attributes over the mineral fertilizer in the non–heat–stress environment and ameliorated the negative impact of heat stress in the heat–stress environment. The ranking of the attributes identified leaf area, dry biomass yield, stem diameter, and plant height as the most discriminating and representative attributes. These attributes should be considered in maize development projects for heat–stress prone areas. Selection of appropriate maize variety and accompanying soil amendment should be integrated into food security strategy as they influenced maize growth and yield under (non–)heat–stress conditions.

A rise in global temperature will reduce maize yield, particularly in Africa, where maize is a staple food. Therefore, improving maize yield under heat stress will promote food security in the region. The objective of this study was to assess the influence of heat stress on the grain yield of drought-tolerant maize varieties under varied growth conditions. The experimental design used was a 2 × 3 × 3 × 2 factorial fitted into a completely randomized design with four replications. The factors were heat stress, maize variety, soil amendment, and soil type. The results showed a better yield from sandy clay loam over loamy sand soil. Varieties WE5323 and ZM1523 amended with poultry manure gave the best yield under the non-heat and heat-stressed environments, respectively. Heat stress reduced the cob weight, grain weight, grain number, and stover dry weight by 64, 73, 69, and 23%, respectively. Grain number, grain weight, and cob weight were the most informative yield attributes in this study and should be considered in a maize selection program. The ranking for the maize varieties was WE5323 > ZM1523 > WE3128. Drought-tolerant maize varieties can be useful in heat stress mitigation. This information is useful for the simulation of maize yields for heat stress-prone areas in Sub-Saharan Africa.

Identificationof agronomic practices that can ameliorate the negative effect of combined heat and water stress on maize plants is vital in food security strategy. The objective of this study was to evaluate the effect of heat and water stress on the growth of maize (Zea mays L.) under variable growth conditions. A repeated greenhouse factorial experiment laid out in a completely randomized design with four replications was performed. The factors were maize variety, water stress, soil amendment, and soil type. The results showed a depressive effect of water stress on the maize leaf area, chlorophyll content, stem diameter, dry biomass yield, and harvest index. These attributes decreased as the severity of the water stress increased with harvest index dipping by 30.3 and 92.9% in moderate water stress (MS) and terminal water‐stress (TS) plants, respectively. Sandy clay loam soil gave higher maize growth and yield attributes than loamy sand soil. The varied growth conditions imposed by the different water stresses, soil types, and soil amendments elicited different responses from the three maize varieties. Mean stability analyses/ranking identified ZM1523 and WE5323 as the top‐performing varieties under poultry manure amendment for both non‐stress and MS conditions, whereas under TS their performance improved in combined poultry manure/mineral fertilizer and mineral fertilizer treatments. Similarly, WE3128 gave its best performance under mineral fertilizer amendment for non‐stress, MS, and TS conditions. Therefore, under combined heat and water stress conditions, the interaction of maize variety, soil type, and soil amendment should be considered to guarantee a high maize yield.