Indigenous fruit tree species (IFTs) can play a crucial role in poverty alleviation and as a source of food in South Africa. Although these species contain nutrient-rich edible fruits that are also locally processed to food products such as jams and jellies, they are still underutilized and also harvested from the wild. This study aimed to prioritize in northern KwaZulu-Natal, IFTs with domestication and commercialization potential. A literature survey and focus groups were used to list tree species that produce edible fruits with this potential. Plant experts, through focus groups and reference group meetings, further ranked fruit trees using a scorecard method based on various attributes. A total of 29 prioritized IFTs was obtained, of which the Sapotaceae was the most represented family with a maximum of four species. Based on scorecard assessment, the most preferred species in descending order wereStrychnos spinosaLam.,Garcinia livingstoneiT.Anderson,Englerophytum magalismontanum(Sond.) T.D.Penn,Sclerocarya birrea(A.Rich) Hochst.,Dovyalis caffra(Hook.f. & Harv) Hook.f.,Vangueria infaustiaBurch. andBerchemia zeyheri(Sond.) Grubov.Strychnos spinosawas ranked as the first most important IFTs with a final score of 151, whereasBerchemia zeyheriwas ranked the least with the final score of 146.1. However, the final scores of all most preferred species were relatively similar to one another. The top seven species identified in this study should be considered as a baseline for future IFTs development programmes such as domestication, whereby these species are introduced to small-holder farmers and food processing industries.

The exploring of biostimulant sources is important for sustainable agriculture. Although all parts of the moringa plant (Moringa oleifera Lam.) are rich in phytohormones and phytochemicals which may be utilised as a potential plant growth enhancer, most attention has been placed on its leaves as a possible biostimulant for enhancing productivity of plants. Little has been reported on moringa seed extract (MSE) as a growth enhancer on medicinal plants. Thus, this study investigated the efficacy of MSE doses (water spray as control, MSE at 2, 4, 6 and 8%) on growth attributes, mineral content and phytochemical compositions of cancer bush plants (Lessertia frutescens L.) grown during the winter–spring and spring–summer seasons of 2021. A gradual increase in growth characteristics, chlorophyll content, phenols and flavonoid contents was recorded in all concentrations of MSE-treated plants compared with controls. Furthermore, all levels of MSE effectively enhanced the concentrations of macronutrients such as calcium, magnesium, phosphorus, nitrogen and potassium as well as micronutrients comprising copper, zinc, iron, manganese and sodium of cancer bush plants relative to untreated plants. Both 6 and 8% MSE concentrations showed high productivity, minerals and phytochemical constituents in cancer bush plants in comparison with 2 and 4% MSE treatments. Overall, the findings of this study demonstrated that, even at low concentrations, MSE can be successfully applied as a biostimulant to improve the growth and biochemical attributes of cancer bush plants.

Sesamum alatum Thonn. is one of the less-popular but nutritious leafy vegetables that is still collected from the wild or as weeds among crops in South Africa. The plant is also used in medicines and cosmetics in Africa and elsewhere. Despite its importance, the cultivation of S. alatum under different agronomic systems for improved harvestable yield and nutrient content is still lacking. The study aimed to determine the response of S. alatum nutrient content to the application of poultry and goat manures. Plants were grown in pots under rain-fed shade cloth conditions, with poultry and goat manures applied at 0, 1, 2, and 3 t ha^–1 each, and they were laid in a completely randomized design. Shoot tips were harvested at 60 days after planting and analyzed for nutrient content. Shoots contained better nutrients in S. alatum plants grown during the first than the second season, with minor exceptions. Poultry and goat manure application led to an increase in Ca, Mg, K, P, and micro-nutrients. Goat manure had potential to increase the nutrient content in S. alatum than poultry manure, although differences were not substantial. Therefore, both manures could be equally used to improve nutrient content of S. alatum.

Strychnos spinosa Lam. of the Loganiaceae family is associated with versatility, poverty eradication, and rural economic development. However, the morphological diversity of S. spinosa is not well documented. This limits efforts toward its improvement and commercial exploitation. This study aimed to characterize the variability, vegetative and reproductive traits, and heritability of S. spinosa morphotypes at Bonamanzi Game Reserve. The majority of the morphotypes had green, rough, round immature fruits with dark green, elongated, open fully developed leaves. Fruits varied between roundish and pyriform shape as well as green and purple colour. Positive correlation was mainly seen between fruit and seed traits. Principal component analysis indicated fruit and seed traits as major discriminating factors for morphotypes, followed by leaf size and seed thickness. A dendrogram primarily grouped morphotypes according to fruit texture. Genotypic variance and genotypic coefficient of variation were higher than environmental variance and environmental coefficient variation in reproductive traits of S. spinosa. A rough pericarp texture and purple tinge on the immature leaves of some morphotypes was recorded for the first time. Differences in morphological features across S. spinosa morphotypes indicate a high level of diversity that could be utilized by breeders to generate new cultivars. This first report on variability and heritability among S. spinosa morphotypes forms the basis of available germplasm essential for future breeding programs.

Corchorus olitorius, a leafy vegetable with high nutrient content, is normally collected from the wild, in areas that are prone to cadmium (Cd) toxicity. However, studies on how Cd accumulation affects vegetative and reproductive traits of leafy vegetables in South Africa are limited. Therefore, this study tested the effect of Cd accumulation on C. olitorius morphological traits. Plants were grown under various Cd concentrations and studied for variation in vegetative and reproductive traits as well as accumulation in roots and shoots. Plants exposed to 5 mg/kg Cd had longer roots with higher moisture content, heavier fresh and dried stems, as well as dried leaves, which indicated a hormetic effect in C. olitorius after exposure to low Cd concentration in the soil. Again, plants treated with 5–10 mg/kg Cd, accumulated toxic (>10 mg/kg dry weight) Cd within shoots and roots, with minor morphological alterations. Plants could survive, with some morphological defects, Cd toxicity up to 20 mg/kg in soil. Only plants exposed to 5 mg/kg could reproduce. Cd accumulation increased with an increase in the soil, with higher accumulation in shoots. The translocation factor was high (>1) in all Cd concentrations. In conclusion, C. olitorius can accumulate toxic Cd, and yet grow and reproduce either normally or better than the control. The proposed dose of Cd that induces hormesis in C. olitorius is 5 mg/kg in the soil. Therefore, C. olitorius is suitable for phytoremediation of Cd contaminated soils, but unsafe for consumption when it grows in such areas.