Potential role for wild vegetables in household food security: a preliminary case study in Kwazulu-Natal, South Africa

The value of wild edible vegetables in food security has not been given sufficient attention in South Africa. Consequently, there are no formal interventions that seek to encourage people to use traditional vegetables as sources of essential nutrients. Studies on the role of wild leafy vegetables in food security could provide important information for development of policies on careful exploitation of natural resources for human sustenance. The objective of this study was to provide a rapid assessment of general knowledge about wild leafy vegetables among subsistence farmers from Ezigeni, a rural location in South Africa, and to determine the availability of wild leafy vegetables from cropping fields during spring - before the cropping season started. A focus group discussion and transect walk were used to collect qualitative data on knowledge of traditional vegetables. Availability of wild leafy vegetables was quantified using one-square-meter plots, randomly located in a cropping field and in an area that has never been cultivated (veld). Results showed that knowledge of wild leafy vegetables among the participants was positively correlated with age. Education status improved knowledge of wild vegetables for middle-aged participants, but not for the youth (35 years or younger). Availability of wild edible leafy vegetables (plant numbers and yield) increased from August to October, but there was a significant difference between species. Data from a focus group discussion showed that wild leafy vegetable availability occurred early in spring, when traditional crops were less abundant. It is concluded that knowledge of wild leafy vegetables may be lost in the near future, unless efforts are made to educate younger generations about their importance. They could be used as an important source of nutrients during the pre-cropping season, before traditional crops are available for human consumption. It is recommended that agronomic investigations into cultivation of wild leafy vegetables that are adapted to rural areas where exotic leafy vegetables are not widely available be undertaken. Those studies could contribute significantly in government policies to improve food security in rural areas, and in the improvement of wild vegetable status, whose potential as sources of nutrition is currently undervalued. Keywords: availability, knowledge, wild leafy vegetables African Journal of Food, Agriculture, Nutrition and Development Vol. 6(1) 200

Growth temperature and plant age influence on nutritional quality of Amaranthus leaves and seed germination capacity

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, temperatur

Water use of sorghum (Sorghum bicolor L. Moench) in response to varying planting dates evaluated under rainfed conditions

It is vital to understand how rainfall onset, amount and distribution between planting dates affect sorghum yield and water use, in order to aid planting date and cultivar selection. This study investigated morphological, physiological, phenological, yield and water use characteristics of different sorghum genotypes in response to different planting dates under rainfed conditions. Four genotypes (PAN8816 [hybrid], Macia [open-pollinated variety, OPV], Ujiba and IsiZulu [both landraces]) were planted on 3 planting dates (early, optimal, and late) in a split-plot design, with planting dates as the main factor. Low soil water at the optimal planting date was associated with delayed crop establishment and low final emergence. Sorghum genotypes adapted to low and irregular rainfall at the late planting date through low leaf number, canopy cover, chlorophyll content index and stomatal conductance, and hastened phenological development. This resulted in low biomass and grain yields. Landraces exhibited grain yield stability across planting dates, whilst OPV and hybrid genotypes significantly reduced grain yield in response to low water availability when planted late. Biomass and grain yield water use efficiency (WUE) were highest at optimal planting date (30.5 and 9.2 kg∙ha-1·mm-1), relative to late (23.1 and 8.7 kg·ha-1·mm-1), and early planting dates (25.2 and 8.3 kg·ha-1·mm-1). For PAN8816 and Macia, biomass and grain WUE decreased in response to low soil water content, and irregular and disproportionate rainfall experienced during the late planting date. By contrast, biomass and grain WUE for Ujiba and IsiZulu improved with decreasing rainfall. PAN8816 is recommended when planting under low soil water availability to maximize crop stand. Cultivation of Macia is recommended under optimal conditions. Ujiba and IsiZulu landraces are recommended for low rainfall areas with highly variable rainfall. Repetition or modelling of genotype responses across environments different from Ukulinga is required for thorough water use characterisation of these genotypes.Keywords: planting dates, water use efficiency, rainfall variability, cultivar selection, landraces and improved sorghum varietie

Positron emission tomographic imaging of Copper 64- and Gallium 68-labeled chelator conjugates of the somatostatin agonist Tyr3-octreotate

The bifunctional chelator and radiometal have been shown to have a direct effect on the pharmacokinetics of somatostatin receptor (SSTR)-targeted imaging agents. We evaluated three Y3-TATE analogues conjugated to NOTA-based chelators for radiolabeling with 64 Cu and 68 Ga for small-animal positron emission tomographic/computed tomograhic (PET/CT) imaging. Two commercially available NOTA analogues, p-SCN-Bn-NOTA and NODAGA, were evaluated. The p-SCN-Bn-NOTA analogues were conjugated to Y3- TATE through β-Ala and PEG 8 linkages. The NODAGA chelator was directly conjugated to Y3-TATE. The analogues labeled with 64 Cu or 68 Ga were analyzed in vitro for binding affinity and internalization and in vivo by PET/CT imaging, biodistribution, and Cerenkov imaging ( 68 Ga analogues). We evaluated the effects of the radiometals, chelators, and linkers on the performance of the SSTR subtype 2–targeted imaging agents and also compared them to a previously reported agent, 64 Cu-CB-TE2A-Y3-TATE. We found that the method of conjugation, particularly the length of the linkage between the chelator and the peptide, significantly impacted tumor and nontarget tissue uptake and clearance. Among the 64 Cu- and 68 Ga-labeled NOTA analogues, NODAGA-Y3-TATE had the most optimal in vivo behavior and was comparable to 64 Cu-CB-TE2A-Y3-TATE. An advantage of NODAGA-Y3-TATE is that it allows labeling with 64 Cu and 68 Ga, providing a versatile PET probe for imaging SSTr subtype 2-positive tumors

Reversible DNA i-motif to hairpin switching induced by copper(II) cations

i-Motif DNA structures have previously been utilised for many different nanotechnological applications, but all have used changes in pH to fold the DNA. Herein we describe how copper(ii) cations can alter the conformation of i-motif DNA into an alternative hairpin structure which is reversible by chelation with EDTA

Assessment of the Nutritional Status of Four Selected Rural Communities in KwaZulu-Natal, South Africa.

Under- and over-nutrition co-exist as the double burden of malnutrition that poses a public health concern in countries of the developing regions, including South Africa (SA). Vulnerable groups such as pregnant women and children under five years are the most affected by malnutrition, especially in rural areas. Major contributing factors of malnutrition include food and nutrition insecurity, poverty, and unhealthy lifestyles. The current study aimed to assess the nutritional status, using selected anthropometric indices and dietary intake methods (repeated 24 h recall and food frequency), of four rural communities in KwaZulu-Natal (SA). Purposive sampling generated a sample of 50 households each in three rural areas: Swayimane, Tugela Ferry, and Umbumbulu and 21 households at Fountain Hill Estate. The Estimated Average Requirement cut-point method was used to assess the prevalence of inadequate nutrient intake. Stunting (30.8%; n = 12) and overweight (15.4%; n = 6) were prevalent in children under five years, whilst obesity was highly prevalent among adult females (39.1%; n = 81), especially those aged 16-35 years. There was a high intake of carbohydrates and a low intake of fibre and micronutrients, including vitamin A, thus, confirming the need for a food-based approach to address malnutrition and micronutrient deficiencies, particularly vitamin A deficiency

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

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

Policy gaps and food systems optimization: a review of agriculture, environment, and health policies in South Africa

South Africa faces the triple burden of malnutrition, high poverty levels, unemployment, and inequality. “Wicked problems” such as these require innovative and transdisciplinary responses, multi-stakeholder coordination and collaboration, managing complex synergies and trade-offs, and achieving sustainable outcomes. Through qualitative content analysis of national and provincial sector-based policies, we explored the interlinkages between the agriculture, environment, and health sectors in South Africa in the context of sustainable food and nutrition security and the extent to which these interlinkages are integrated into policy and planning. A systemic analysis of the review outcomes was performed to identify its main learning outcome, the status quo in the policy process. The nature of feedback loops was identified, and a leverage point was suggested. The review highlighted that policymakers in the agriculture, environment and health sectors are aware of, and have understood, the relationships among the three sectors. They have also made attempts to address these interlinkages through collaboration and coordination. Unfortunately, this has been met with several challenges due to fragmented sector-specific mandates and targets and a lack of resources for integrated solutions. This creates implementation gaps and unintended duplication of activities, leading to poor service delivery. Transitioning to sustainable and healthy food systems will only be possible after these gaps have been closed and implementation optimization has been achieved. Focusing on meta-level problem-framing, functional collaboration through transdisciplinary approaches, and integrated targets are critical to successful policy implementation and progressive realization of national goals related to sustainable food and nutrition security, unemployment, poverty, and inequality

Assessing Progress towards Sustainable Development Goals through Nexus Planning

Sustainable Development Goals (SDGs) acknowledge the inter-linkages between human wellbeing, economic prosperity, and a healthy environment and, hence, are associated with a wide range of topical issues that include the securities of water, energy and food resources, poverty eradication, economic development, climate change, health, among others. As SDGs are assessed through targets to be achieved by 2030 and monitored through measurable indicators, this study applied the nexus planning model to monitor and evaluate progress towards SDGs using South Africa as a case study. The study highlighted pathways to ensure socio-ecological sustainability and environmental health by establishing the connectivity between SDGs and nexus approaches. The linkages between SDGs and nexus planning facilitated the sustainable management of resources in an integrated manner. They addressed the cross-sectoral synergies, value-addition, and trade-offs within interlinked sectors. The connectedness of current challenges facing humankind (climate change, rapid urbanisation, migration, and the emergence of novel infectious diseases) require transformative approaches that address these cross-cutting challenges holistically. Managing the intricate relationships between distinct but interconnected sectors through nexus planning has provided decision support tools to formulate coherent strategies that drive resilience and sustainability. The established linkages between nexus planning and SDGs have strengthened cross-sectoral collaboration and unpacked measures for cooperative governance and management through evidence-based interventions. As food production, water provision, and energy accessibility are the major socio-economic and environmental issues currently attracting global attention; the methodology promotes attaining sustainability by 2030