African Leafy Vegetables for Improved Human Nutrition and Food System Resilience in Southern Africa: A Scoping Review

Concentrations and health risks of selected elements in leafy vegetables: a comparison between roadside open-air markets and large stores in Johannesburg, South Africa

This study compared concentrations and health risks of selected elements (Al, As, Cd, Co, Cr, Cu, Hg, Ni, Pb, Zn) in leafy vegetables (coriander, lettuce, mint, spring onion, swiss chard) from roadside open-air markets (OM) and large stores (supermarkets: SM, vegetable markets: VM) in Johannesburg, South Africa. Along with washed leaves (OMW, SMW, VMW), unwashed OM leaves (OMUW) were assessed to investigate the contribution of deposition. The findings revealed that OMUW leaves had the highest concentrations of all elements. Furthermore, compared with washed leaves, OMUW leaves showed significantly higher (p < 0.05) mean concentrations of Cd, Hg, Ni and Pb, elements that typify the composition of polluted urban air. Bi- and multivariate analysis indicated anthropogenic origin of most elements in OM leaves and several in SMW and VMW leaves. Although only OMUW leaves exhibited hazard quotient above the safe threshold of 1 for Cd, Cr, As and Ni, hazard index exceeded this safe limit in all samples (OMUW (11.77) > OMW (1.83) > SMW (1.29) > VMW (1.01)). Determined cancer risk for Cd and As was greater than 1 × 10-6 in both washed and unwashed leaves, and the greatest cancer risk was estimated for OM leaves. Thorough washing of OM vegetables with water reduced non-carcinogenic risk (84%) and cancer risk (74‒87%) markedly. In conclusion, residents primarily relying on open-air markets for their regular leafy vegetable supplies might face far more severe lifelong health implications compared to customers of large stores in Johannesburg.

Study on characters associations and path coefficient analysis for quantitative traits of amaranth genotypes from Ethiopia

Selection based on yield alone may not be effective for yield improvement in plant breeding programs. Thus, in order to progress the genetic gains during selection, yield should be considered along with potential yield contributing traits. The objective of this study was to improve the genotype of amaranth and increase the effectiveness of selection in the program by identifying the correlation and path coefficients between yield and its relevant attributes. On 120 genotypes of amaranth planted during two growing seasons in 2020 and 2021, the study was carried out using an alpha lattice design with two replications. The results revealed significant positive phenotypic and genotypic associations on leaf yield, with leaf area, leaf breadth, branch number, leaf number, plant height at flowering, and grain yield all having positive direct effects. Similar strong positive phenotypic and genotypic relationships were found for grain yield and grain sink filling rates. Using path coefficient analysis, the direct and indirect effects of yield-related traits on yield were also determined. In addition to having a strong direct impact on grain output, the grain sink filling rates showed both phenotypic and genotypic evidence of substantial positive relationships with grain yield. It was further suggested that leaf yield in amaranth genotypes may increase through the indirect selection of plant height at maturity, leaf length, and terminal inflorescence lateral length, which showed such significant indirect influences, mostly through leaf area, days to maturity, and days to emergence, which displayed such strong indirect effects, primarily through plant height at flowering. This study consequently shows the need for traits with significant positive indirect impacts via leaf area to be considered indirect selection criteria for improving leaf yield in amaranth genotypes. The grain sink filling rate also significantly improved grain yield indirectly at both the phenotypic and genotypic levels, mainly via days to flowering and leaf yield. This demonstrated that selection that mainly targeted days to flowering, leaf yield, and grain sink filling rate would ultimately boost the grain yield in amaranth genotypes.

Effect of Consumers' Acceptance of Indigenous Leafy Vegetables and Their Contribution to Household Food Security

In the past decades, indigenous leafy vegetables (ILVs) have played a significant role in household food security, especially in poor rural households. However, ILVs have been replaced by exotic cash crops in the contemporary world. This study was conducted to assess the consumption of indigenous leafy vegetables and their contribution to household food security of households in Limpopo and Mpumalanga provinces. The study used secondary data collected by the South African Vulnerability Assessment Committee in 2016. A total of 1520 respondents were selected using a multistage sampling method. The results from descriptive statistics revealed that most consumers did not produce ILVs but consumed them. Meanwhile, a small number of people produced ILVs yet did not consume them. The results from the Household Food Insecurity Access Scale (HFIAS) showed that a large proportion of the population experienced moderate food security while some of the individuals within the population experienced severe food insecurity. An endogenous switching regression model (ESRM) was employed to analyze the impact of the consumption of ILVs on household food security. The results revealed that only a few variables of the consumption of ILVs were significant and positive (household size, wealth index, and 'if the disabled person receives grants'). As a result, the consumption of ILVs had a minimal impact on the household food security of the Limpopo and Mpumalanga provinces. The findings further revealed that age, gender, and education variables negatively influenced the consumption of ILVs. Thus, the recommended programs must be established to educate people about the importance of consuming ILVs. Agricultural extension services must equally promote the consumption of exotic cash crops and ILVs. Lastly, policies can contribute by increasing the diversity of ILVs left at retail outlets through diverse production.

The Role of Indigenous Vegetables to Improve Food and Nutrition Security: Experiences From the Project HORTINLEA in Kenya (2014–2018)

Many warning signs indicate that the food security goals formulated in 2015 will not be achieved. This situation is particularly true for the African continent. After substantial progress up to 2015, the situation has hardly improved or has worsened in many respects. In addition to the rapid population growth, the increasingly frequent long dry periods or sometimes erratic rainfall have contributed to this. In addition, current production systems have dysfunctional side effects due to increasing yield optimization and specialization. Thus, besides the associated resource degradation, it also leads to a monotonous food supply and the emergence of vitamin and mineral deficiencies (hidden hunger). A meaningful way to diversify the food supply is to cultivate and market previously underutilized species. However, they are characterized by not being known and traded globally and usually having only local importance. Accordingly, they have been widely ignored in research. Increasingly, however, there is a growing realization worldwide that these plants can make an essential contribution to food and nutrition security, especially for poorer segments of the population. Moreover, they are adapted to local conditions and are often produced with less resource input. This article aims to show how these species can be better utilized to provide nutritious food through sustainable production, using the example of African indigenous vegetables. In doing so, the impact of emerging social and ecological changes in Kenya will be considered. This source is an interdisciplinary collaborative research project, Horticultural Innovation and Learning for Improved Nutrition and Livelihood in East Africa (HORTINLEA), which was carried out in Kenya from 2014 to 2018. Many different disciplines were involved in the German-African cooperation project. The results will be brought together in this article with the help of a food-sensitive value chain approach, and the experiences gained from this project will be reflected.

Considering Ecosystem Services in Food System Resilience

The prevalence and severity of natural hazards pose a serious risk to food systems, undermining their function to provide food security and improved nutrition. The impact of such events is extensive, and the level of damage and recovery significantly depend on ecosystem services, including their own resilience capacity. This paper provides evidence that the role, value, and utilization of local ecosystem services are essential for food system resilience and for food security in parts of the world where high vulnerability and lack of coping capacity exist to combat climate change. Patterns of ecosystem services-based strategies were revealed that can be introduced to cope and adapt to climate-related natural hazards at the smallholder food system level. The study suggests that food system diversification, technological innovations and nature-based practices, and traditional and indigenous knowledge operationalized across the food system components have a potential for sustaining smallholder resilience in the face of natural hazards.