Search Results (22)

Biodiversity conservation has been identified as an important climate change mitigation tool. Healthy ecosystems act as natural carbon sinks while also strengthening resilience, making them essential for climate change adaptation. Climate change effects have led to various negative impacts, including biodiversity loss and food insecurity. The loss of forest biodiversity threatens vital wild fruits and vegetables that sustain rural communities, disrupting natural food sources and constituting a form of social injustice for poor, vulnerable, and previously marginalised groups in rural and semi-urban communities. Therefore, this study aimed to investigate the relationship between previous biodiversity conservation outcomes, ecosystem services, highly utilised wild vegetables and fruits, food and nutritional security, climate change effects, and climate resilience. We identified gaps in African biodiversity conservation and developed a conceptual framework to highlight integral principles required for the effective biodiversity conservation of wild forests in Africa. The integral principles are active community engagement, a strong network of stakeholders, sustainable plant resources management practices, legal reforms, and the creation of awareness through various platforms. Conservation policies should prioritise African indigenous wild, drought-tolerant vegetables and fruits that serve as an interface between food and medicine; play various roles in human survival in the form of ecosystem services; and act as carbon sinks to ensure a food-secure future with reduced climate change effects. The African indigenous community’s efforts in biodiversity conservation engagements are key to successful outcomes. Full article

The instability between water demand and availability is making it challenging to cultivate viable, sustainable crops. To address this, improved irrigation scheduling regimes need to be adopted, focusing on full crop water requirements to determine optimal water allocation. This study aimed to identify suitable intercropping combinations of leguminous dry bean plants with indigenous African leafy vegetables (specifically cleome gynandra and cucumis myriocarpus) that could enhance interactions with regulated deficit irrigation. The experiment was designed in 3 (irrigation levels: 100%, 75%, and 50%) × 5 (three monocrops and two intercrops) split plot arrangement within a randomized complete block design (RCBD), replicated three times across four growth stages. The study was designed to rigorously assess the effectiveness of two intercrops compared to three monocrops, each cultivated under varying irrigation levels of 100%, 75%, and 50%. There was an increase in selected gaseous parameters, such as stomatal conductance and photosynthesis rates when dry beans were intercropped with cucumis myriocarpus and subjected to 75% deficit irrigation during the mid-pod stage of the dry bean. In contrast, decreased gaseous parameters were noted under a 50% deficit irrigation across all dry bean growth stages, which also negatively affected the growth of African leafy crops. Regarding yield, an inverse relationship was observed between the crops. The yield of dry beans significantly increased under 75% irrigation during the mid-pod stage. Meanwhile, yields of cucumis myriocarpus increased under both 75% and 100% irrigation levels during the early-pod stage of the dry beans, which corresponded to the vegetative stage of the two African leafy crops. In conclusion, regulating irrigation under 75% deficit irrigation during the mid-growth stage is recommended as an ideal irrigation level for intercropping dry beans with cucumis myriocarpus, and this can potentially save 25% of water. Full article

Prosopis glandulosa (Mesquite), an invasive alien tree species, poses major threats to soil health, native vegetation, and biodiversity in South African rangelands. The negative impacts of Prosopis on socio-economic, environmental, and ecological resources outweigh the benefits. Most South African researchers are afraid that if left uncontrolled or poorly managed, it can cause severe land degradation, reduced agricultural productivity, indigenous-species shift, and ultimately the loss of biodiversity. Consequently, this will undermine key sustainable development goals related to food security and environmental conservation. In this review we conducted a systematic review, identifying 309 peer-reviewed articles from Google Scholar and Web of Science, screening and analyzing 98 of these, and ultimately reviewing 34 publications in detail. Three key research gaps were identified: (1) insufficient research focused on Prosopis invasion in South Africa; (2) limited integration and collaboration between the agricultural sector, environmental conservation sector, and governmental bodies; and (3) challenges in policy implementation within invaded areas. The study seeks to address these gaps by highlighting the impact of this alien invasive Prosopis species on land, biodiversity, and overall ecosystem stability. It also investigates policy issues surrounding invasive species and their control. Effective management of Prosopis within the country will not only control the spread but also support the broader objectives of environmental conservation, agricultural sustainability, and socio-economic development. Full article

Nutrient profiling (NP) models that assess nutrient density of foods can help remedy micronutrient deficiencies. We used NP methods to identify the most nutrient-rich foods in the 2019 FAO/INFOODS Western Africa Food Composition Table (WAFCT). The WAFCT had complete data for 909 foods. Three versions of the well-established Nutrient-Rich Food (NRF) model were used: (1) the original NRF9.3 based on 9 micronutrients (protein, fiber, calcium, iron, potassium, magnesium, vitamin A, vitamin C, and vitamin D); (2) a new NRF6.3 based on 6 priority micronutrients (iron, zinc, calcium, folate, vitamin A, vitamin B12); and (3) NRF 15.3, based on 15 nutrients to encourage (NRF6.3 nutrients + vitamin D, vitamin E, vitamin C, vitamin B1, vitamin B2, vitamin B3, vitamin B6, copper, and magnesium). Data analyses used one-way ANOVAs and independent t-tests, with significance at α = 0.05. Animal-source foods were rated higher by NRF6.3 priority micronutrient and NRF15.3 NP models than by the NRF9.3 model. African indigenous vegetables had higher protein content and higher nutrient density compared to non-indigenous vegetables, and African indigenous grains had higher nutrient density compared to non-indigenous grains. Though animal-source foods received some of the highest scores, NP models adapted to the West African context showed that African indigenous vegetables and grains were also nutrient rich. Indigenous foods could be important sources of priority micronutrients for the region. Full article

Microgreens are innovative vegetable products whose production and consumption are gaining popularity globally thanks to their recognized nutraceutical properties. To date, the effects of lighting conditions and growing substrate on the performances of Brassica carinata microgreens (indigenous to Africa) remain underexplored. The present study aimed at providing insights into the influence of different lighting treatments provided by LEDs, namely monochromatic blue (B), red (R), cool white (W) and a combination of three color diodes (B + R + W), and substrates (cocopeat, sand and cocopeat–sand mix (v/v) (1:1)) on the growth, yield and bioactive compounds of B. carinata microgreens. Seeds were germinated in dark chambers and cultivated in growth chambers equipped with LED lighting systems for 14 days under a fixed light intensity of 160 ± 2.5 µmol m⁻² s⁻¹ and photoperiod of 12 h d⁻¹. The best performances were associated with the spectrum that combined B + R + W LEDs and with substrate resulting from the cocopeat–sand mix, including the highest yield (19.19 g plant⁻¹), plant height (9.94 cm), leaf area (68.11 mm²) and canopy cover (55.9%). Enhanced carotenoid and flavonoid contents were obtained with B + R + W LEDs, while the B LED increased the total amount of chlorophyll (11,880 mg kg⁻¹). For plants grown under B + R + W LEDs in cocopeat, high nitrate levels were observed. Our results demonstrate that substrate and light environment interact to influence the growth, yield and concentration of bioactive compounds of B. carinata microgreens. Full article

Traditionally, indigenous African leafy vegetables such as Amaranthus, blackjack, jute mallow, cleome monophyla, and spider plants have been conventionally and organically grown as weeds in open fields. However, the lack of land space due to the increase in population has resulted in unconventional, modern, and advanced agricultural farming. The introduction of a greenhouse has recently become the second most popular growing system alongside shade net and glasshouse to increase productivity and meet consumers’ demand. Several studies on Amaranthus species have solely focused on physiological parameters and nutritional composition, leaving a huge gap on their metabolomic profile of the leaves which is crucial to comprehend when growing Amaranthus species in different cropping systems. Therefore, the study aimed to determine the influence of different cropping systems on the release of metabolites of two commonly consumed Amaranthus species in South Africa. H¹ -Nuclear Magnetic Resonance (NMR) tool was used to profile the untargeted metabolites of green (Amaranthus graecizans L.) and red (Amaranthus cruentus L.) species. A total of 12 metabolites—trehalose, betaine, glutamine, choline, sucrose, caprate, adenosine, asparagine, carnitine, caffeine, aspartate, and alanine—were detected in green amaranth grown in open fields. Except for caffeine, aspartate, and caprate, which were found in the green amaranth grown in open fields, all the other metabolites were detected in the greenhouse grown once. Interestingly, allantoin, which serves as an allelochemical, was the sole distinct metabolite detected in greenhouse cultivated green amaranth. On the contrary, seven similar metabolites were quantified in red amaranth grown in both open fields and greenhouses, apart from caffeine, which was only detected in greenhouse-cultivated red amaranth. Full article

Antimicrobial resistance is considered a “One-Health” problem, impacting humans, animals, and the environment. The problem of the rapid development and spread of bacteria resistant to multiple antibiotics is a rising global health threat affecting both rich and poor nations. Low- and middle-income countries are at highest risk, in part due to the lack of innovative research on the surveillance and discovery of novel therapeutic options. Fast and effective drug discovery is crucial towards combatting antimicrobial resistance and reducing the burden of infectious diseases. African medicinal plants have been used for millennia in folk medicine to cure many diseases and ailments. Over 10% of the Southern African vegetation is applied in traditional medicine, with over 15 species being partially or fully commercialized. These include the genera Euclea, Ficus, Aloe, Lippia. And Artemisia, amongst many others. Bioactive compounds from indigenous medicinal plants, alone or in combination with existing antimicrobials, offer promising solutions towards overcoming multi-drug resistance. Secondary metabolites have different mechanisms and modes of action against bacteria, such as the inhibition and disruption of cell wall synthesis; inhibition of DNA replication and ATP synthesis; inhibition of quorum sensing; inhibition of AHL or oligopeptide signal generation, broadcasting, and reception; inhibition of the formation of biofilm; disruption of pathogenicity activities; and generation of reactive oxygen species. The aim of this review is to highlight some promising traditional medicinal plants found in Africa and provide insights into their secondary metabolites as alternative options in antibiotic therapy against multi-drug-resistant bacteria. Additionally, synergism between plant secondary metabolites and antibiotics has been discussed. Full article

Okra (Abelmoschus esculentus) is an important vegetable that has been indigenized in African countries where it is consumed as a relish. There is still, however, a lack of documented cultivation techniques for better yields. An organic medium-enclosed trough (OMET) system is a growing technique that has been developed to reduce water and nutrient seepage during plant production. The study objectives evaluated the effect of OMET on the growth, yield, and nutritional attributes of okra. A complete randomized block design was established to accommodate the two treatments: OMET and non-OMET, in a micro-plot under field conditions. The stem diameter and plant height were recorded weekly during plant growth, and a clear increasing trend in OMET over non-OMET was observed from week 4 of transplantation. The OMET growing technique significantly increased the stem diameter and plant height by 37 and 48%, respectively. When evaluating the yield attributes, a similar trend was observed, where the OMET system significantly increased the yield attributes of okra as follows: biomass by 50%, the number of branches by 50%, the number of pods per plant by 49%, fresh pod weight by 53%, and pod length by 51%, while there was no significant difference in pod diameter width. Non-essential amino acids compounds, including arginine, serine, glycine, aspartate acid, glutamic acid, alanine, and proline and essential amino acids, including histidine, threonine, methionine, lysine, tyrosine, leucine, phenylalanine, asparagine and glutamine, were highly maintained in OMET compared to non-OMET. OMET enhanced the upregulation of proteins, Ca, Mg, K, Mn, Na, P and Zn elemental nutrients in the disposal of less irrigation water than non-OMET. This growing technique could be recommended for small-scale and commercial farming to improve the okra production of nutrition. Full article

Previously, researchers have not paid attention to indigenous African leafy vegetables such as nightshade and kale, however, amaranth species have recently gained popularity due to their adaptability to various climatic conditions and their cultivation in both open fields and hydroponics. Amaranth species are ranked among the underutilized leafy vegetables with medicinal properties, economic values, nutritional and health benefits. This study aimed to compare the growth parameters and nutritional composition of two consumed red (Amaranthus Cruentus L.) and green (Amaranthus Graecizans L.) amaranth species in South Africa, cultivated in an open field versus a greenhouse. The findings showed a high chlorophyll content and large leaf area under open field conditions on red and green species. The number of leaves and stem height were higher in the greenhouse cultivation system. In open field cultivation, minerals such as calcium, magnesium, phosphorus, iron, zinc, aluminium, copper and manganese for both species were significantly higher whilst potassium, sodium, boron, sulphur were significantly higher in the greenhouse production. The sufficient total nitrogen and ash were recorded in the open field production, and no significant difference was observed between the open field and greenhouse on moisture and ash content of A. Cruentus. In conclusion, A. Cruentus and A. Graecizansn grown in an open field had higher proximate and mineral composition over the greenhouse cultivation system. Full article

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. Full article

South Africa is blessed with vast plant resources and unique vegetation types. Indigenous South African medicinal plants have been well-harnessed to generate income in rural communities. Many of these plants have been processed into natural products to heal a variety of diseases, making them valuable export commodities. South Africa has one of the most effective bio-conservation policies in Africa, which has protected the South African indigenous medicinal vegetation. However, there is a strong link between government policies for biodiversity conservation, the propagation of medicinal plants as a source of livelihood, and the development of propagation techniques by research scientists. Tertiary institutions nationwide have played a crucial role in the development of effective propagation protocols for valuable South African medicinal plants. The government-restricted harvest policies have also helped to nudge natural product companies and medicinal plant marketers to embrace the cultivated plants for their medicinal uses, and thus have helped support the South African economy and biodiversity conservation. Propagation methods used for the cultivation of the relevant medicinal plants vary according to plant family and vegetation type, among others. Plants from the Cape areas, such as the Karoo, are often resuscitated after bushfires, and propagation protocols mimicking these events have been established through seed propagation protocols with controlled temperatures and other conditions, to establish seedlings of such plants. Thus, this review highlights the role of the propagation of highly utilized and traded medicinal plants in the South African traditional medicinal system. Some valuable medicinal plants that sustain livelihoods and are highly sought-after as export raw materials are discussed. The effect of South African bio-conservation registration on the propagation of these plants and the roles of the communities and other stakeholders in the development of propagation protocols for highly utilized and endangered medicinal plants are also covered. The role of various propagation methods on the bioactive compounds’ composition of medicinal plants and issues of quality assurance are addressed. The available literature, media online news, newspapers, and other resources, such as published books and manuals, were scrutinized for information. Full article

Traditional preparation of African indigenous vegetables (AIVs) such as African black nightshade (Solanum nigrum) and African spiderplant (Cleome gynandra) involves either boiling and discarding the first water or lengthy boiling. Fermentation is considered a better alternative processing technique due to the enhanced retention of phytochemical contents and sensory properties. However, little is known about the impact of lactic acid fermentation on the phytochemical content, antioxidant capacity, sensory acceptability and microbial safety of the African black nightshade and African spiderplant. This study aimed to ferment AIVs using combined starter cultures (Lactobacillus fermentum and Lactococcus lactis) and further determine their effect on the phytochemical content (phenolic compounds and flavonoids), antioxidant capacity, sensory acceptability and microbial safety of the vegetables. There was a marked increase in phenol and flavonoid contents in all fermented vegetables (p < 0.05). The highest phenol content was 228.8 mg/g GAE (gallic acid equivalent) in the starter-culture-inoculated African black nightshade, while flavonoid content was 10.6 mg/g QE (quercetin equivalent) in the same. Starter-culture-inoculated AIVs presented significantly higher antioxidant capacity with a 60–80% radical scavenging activity compared to levels in uninoculated batches (p < 0.05). Fermented vegetables were more liked than the boiled vegetables and were microbiologically safe. In conclusion, lactic fermentation of AIVs increased phytochemical contents (phenolic compounds and flavonoids), maintained antioxidant capacity and improved product safety and sensory acceptability. Therefore, fermentation and consumption of the African indigenous vegetables are to be encouraged. Full article

African indigenous leafy vegetables (AILVs) are plants that have been part of the food systems in Sub-Saharan Africa (SSA) for a long time and their leaves, young shoots, flowers, fruits and seeds, stems, tubers, and roots are consumed. These vegetables are high in vitamins, minerals, protein, and secondary metabolites that promote health. This study aimed at isolating, characterizing, and identifying dominant lactic acid bacteria (LAB) from naturally fermenting commonly consumed AILV in Kenya. A total of 57 LAB strains were isolated and identified based on phenotypic and 16S rRNA gene analyses from three AILVs (23 nightshade leaves, 19 cowpeas leaves, and 15 vegetable amaranth). The highest microbial counts were recorded between 48 h and 96 h of fermentation in all AILVs ranging from approximately log 8 to log 9 CFU/mL with an average pH of 3.7. Fermentation of AILVs was dominated by twenty eight Lactobacillus spp. [Lactiplantibacillus plantarum (22), Limosilactobacillus fermentum (3), Lactiplantibacillus pentosus (2) and Lactiplantibacillus casei (1)], eleven Weissella spp. (Weissella cibaria (8), W. confusa (2), and W. muntiaci) six Leuconostoc spp. [Leuconostoc mesenteroides (3), Leuc. citreum (2) and Leuc. lactis (1)], six Pediococcus pentosaceus, four Enterococcus spp. [Enterococcus mundtii (2), E. faecalis (1) and E. durans (1)] and, finally, two Lactococcus garvieae. These bacteria strains are commonly used in food fermentation as starter cultures and as potential probiotics. Full article

Poor nutrition during the first two years of life has long term consequences, but resource-poor households often do not have the means to access nutrient-dense and diverse diets. Pooled data of 24-h dietary recalls (n = 3336) and 2019 retail food prices were analyzed to determine associations of retail cost and energy cost (per 100 kcal) with diet quality indicators for diets of 6–24-month-old South African children who were breastfed (BF-diet) and not breastfed (NBF-diet) during the 24-h recall period. Compared to the BF-diet, retail cost for the NBF-diet was three times higher for age 6–11 months, and double for age 12–17 months. Higher retail cost and energy cost were both associated with higher mean adequacy ratios and dietary diversity scores for BF and NBF diets, except energy cost for the NBF-diet for age 6–11 months. Overall, inclusion of flesh foods, vitamin A-rich fruits and vegetables, and other fruit and vegetables increased from the lowest to the highest retail cost tertile. The higher cost of more nutritious diets highlights the importance of the affordability of diets in interventions aimed at improving diet quality. Possible strategies include: identifying the most-affordable foods within each food group, focusing on foods that provide multiple key micronutrients, and the inclusion of locally available indigenous foods. Full article

Nightshades are among many underutilized and neglected African indigenous leafy vegetable (AILVs) species, and if adequately exploited, they could improve food, nutrition and income among the rural population. Morphological characterization of available accessions is key for the breeder to identify and select superior accessions as parents for utilization in breeding programs. Fifteen accessions of nightshade were evaluated for morpho-agronomic variation in an open field trial implemented in a randomized complete block design with three replicates across the two growing seasons. The accessions exhibited significant (p < 0.0001) differences in all quantitative traits. The data analysis showed that Scabrum (805.30 g/plant) followed by Ncampus (718.60 g/plant) produced the highest fresh leaf yield; for fruit fresh yield, the accession NigSN18 (1782.00 g/plant) recorded the highest, followed by ManTown (1507.90 g/plant). The accession N5547 had the tallest plants (66.83 cm), followed by accession Timbali (62.31 cm). The first four principal components (PCs) accounted for 86.82% of the total variation, which had an eigenvalue greater than 1. The cluster analysis grouped the accessions into 14 clusters based on their genetic similarity. Results of genetic studies revealed that phenotypic coefficient variation was higher than genotypic coefficient of variation for all parameters evaluated, indicating the environmental influence on the expression of these traits. Both GCV and PCV were higher for the largest leaf area, moderate to high for the remaining characters and low for leaf fresh yield per plant. High heritability coupled with genetic advance as a mean percentage (H²-70.59%, GAM-142.4%), indicating the presence of additive gene effects. Hence, selection can be employed for the improvement of this trait in nightshades. The study revealed sufficient genetic variability in the nightshade accessions, which can be exploited for crop improvement. Full article