African leafy vegetables (ALVs) are mostly gathered from the wild, with few selected species being cultivated, usually as part of a mixed cropping system in home gardens or smallholder plots. They have important advantages over exotic vegetable species, because of their adaptability to marginal agricultural production areas and their ability to provide dietary diversity in poor rural communities. Despite their significance in food and nutrition security, there is limited availability or access to these crops leading to underutilisation. The objective of this review was to document the state of utilisation and production of ALVs in South Africa. A qualitative systematic approach review of online sources, peer reviewed papers published in journals, books and other publications was conducted. There is lack of suitable production systems, innovative processing, and value-adding techniques that promote utilisation of ALVs. Furthermore, there is a perception that ALVs are food for the poor among the youth and urban folks, while, among the affluent, they are highly regarded as being nutritious. To promote ALVs from household consumption and commercialisation, further research on agronomy, post-harvest handling, storage and processing is required in South Africa.

A study was undertaken to assess variation in antioxidant, antimicrobial and phytochemical properties of thirteen Moringa oleifera cultivars obtained from different locations across the globe. Standard antioxidant methods including the DPPH scavenging, ferric reducing power (FRAP) and β-carotene-linoleic acid model were used to evaluate the activity. Variation in the antioxidant activity was observed, with TOT4951 from Thailand being the most active, with activity five times higher than that of ascorbic acid (reference compound). A different trend was observed for the activity in the FRAP and β-carotene-linoleic acid assays. Antimicrobial activity was tested against Gram-positive (Staphylococcus aureus) and Gram-negative (Klebsiella pneumoniae) strains using the microdilution method. Acetone extracts of all cultivars exhibited good antibacterial activity against K. pneumoniae (MIC values of 0.78 mg/mL). The remaining extracts exhibited weak activity against the two microorganisms. For the antifungal activity, all the extracts exhibited low activity. Variations were observed in the total phenolic and flavonoid contents. Cultivars TOT5169 (Thailand) and SH (South Africa) exhibited highest amounts of total phenolic compounds while TOT5028 (Thailand) exhibited the lowest amounts of five times lower than the highest. The information offer an understanding on variations between cultivars from different geographical locations and is important in the search for antioxidant supplementation and anti-ageing products.

The adoption of climate-smart irrigation technologies amongst smallholder farmers generally remains low beside their role in combating food and nutrition security in a society and in climate change adaptation strategies. This study identified the factors influencing smallholder farmers’ decision to adopt Climate Smart Irrigation Technologies (CSIT) in the Limpopo Province of South Africa. Data were collected through the completion of a face-to-face structured questionnaire by 100 smallholder farmers selected through convenience and purposive sampling. A probit regression and OLS model were used to identify factors that influence the smallholder farmer’s decision to adopt CSIT and the level of adoption. The results indicated that only 46% of the smallholder farmers adopted climate-smart irrigation technologies and suggested that adoption is influenced positively by factors such as gender, age, district, farm size, staple food production and knowledge on CSIT. There is an urgent need for related stakeholders to transform the smallholder farmer subsector through improved extension services, training, adopting resilient crop varieties, promoting underutilized and nutrient-dense crops adapted to harsh local conditions, and other interventions. This should be done by promoting awareness to smallholder farmers regarding these interventions and new technologies that have the potential to improve rural livelihoods and enhance resilience and adaptation.

Climate change continues to impact the livelihoods of smallholder farmers due to low adaptive capacity. In South Africa, the challenge is exacerbated by water scarcity and shortened crop-growing seasons. Climate-smart irrigation innovative technologies (CSIT) enhance smallholder farmers’ resilience to climate change. However, there is still a limited level of effective adoption and usage of these technologies in smallholder communities. This study investigated the barriers affecting the adoption of CSIT in rural areas of the Vhembe and Capricorn districts in Limpopo Province, South Africa. We explored the farmers’ socioeconomic factors extracted from farmers’ perceptions of CSIT-specific attributes. A multi-stage randomized sampling technique was used to select 100 smallholder farmers (SHF). Data analyzed by descriptive statistics such as percentages and frequency distribution are presented in graphs and tables. According to the findings, insufficient communication channels, a lack of financial availability, unstable land tenure systems, and insufficient training are the main obstacles to implementing CSIT. There is a need for policy and decision-makers to improve the communication channels for disseminating agro-meteorological information to the intended beneficiaries.

Seed germination is a crucial step in plant propagation, as it controls seedling production, stand establishment and ultimately crop yield. Approaches that can promote seed germination of valuable crops remain of great interest globally. The current study evaluated the effect of biostimulant (Kelpak^® and plant-growth-promoting rhizobacteria—PGPR) biopriming on the seed germination of five (VI037996, VI046567, VI055421, VI050956, and VI033796) Abelmoschus esculentus genotypes. The germination responses of the bio-primed seeds were measured using six parameters, including final germination percentage (FGP), mean germination time (MGT), germination index (GI), coefficient of velocity of germination (CVG), germination rate index (GRI), and time spread of germination (TSG). Biostimulant application significantly affected MGT (1.1–2.2 days), CVG (1.4–5.9), and TSG (1.2–3.0 days). Genotype also significantly influenced the TSG (1–3 days). Significant interaction effect of biostimulant treatment and genotype was evident on the FGP, GI, and GRI of the germinated seeds. The most noteworthy effect was demonstrated by Kelpak^® (1:100) applied to genotype VI037996, with significantly improved FGP (82%), GI (238), and GRI (77%/day) when compared to the control. Overall, the current findings suggest the potential stimulatory effect of biostimulants (especially Kelpak^®) on the germination of Abelmoschus esculentus seeds. However, this influence was strongly dependent on the type of genotype.

Low available soil phosphorus (P) is associated with its immobility, which renders it unavailable for plant uptake. In addition, farmers normally apply inorganic fertilisers to legumes to activate soil-bound phosphorus using root exudates. Sufficient soil mineral nutrition is key to sustainable crop production, and hence food and nutritional security. The aim of this study was to quantify the acid and alkaline phosphatase activity as an indicator of P supply and availability under varying levels of nitrogen, phosphorus and potassium (NPK) fertilization and different cropping systems. An intercropping (cowpea and amaranth) and fertiliser (control, 25%, 50%, and 100% of the recommended NPK levels) field trial was laid out in a 2 × 4 factorial treatment structure in a completely randomized design (CRD) with four replications. There was higher acid and alkaline phosphatase activity in the rhizosphere of cowpea and amaranth grown as sole crops compared to those from intercropping. The cowpea and amaranth plants grown without fertiliser or 25% NPK had the highest rhizospheric phosphatase activity, while 100% NPK application exhibited the least. The markedly higher phosphatase activity from the low fertiliser application treatments indicates the possible stimulation of microbial activity to supplement P demands for the crops. The study revealed that the application of lower rates inorganic fertilisers in a legume intercrop stimulates the activity of the phosphatase enzymes, which can subsequently liberate soil-bound phosphorus. Plant tissue phosphorus concentration of cowpea and amaranth plants increased proportionately to the increase in fertiliser application up to 50% of the recommended NPK level. The land equivalent ratio (LER) was greater than 1, indicating that it is more beneficial to intercrop cowpea and amaranth as opposed to growing them as sole crops. Overall, the application of NPK fertilizer to amounts of up to 50%, based on the results of this study, appear to be better than 100% in terms of biomass accumulation and phosphate activity.