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Background: Cannabis sativa is a high-value crop that can be cultivated for ruminant’s feed and medicinal purposes. The demand for Cannabis and Cannabis products has increased since the beginning of 21st century. Objectives: The increase in the production cost of high-protein feeds such as lucerne has led to an urgent need to investigate alternative high-protein sources. Methods: Cannabis has been identified as an alternative to lucerne due to its high protein content. Results: However, the cultivation and uses of Cannabis and its by-products in South Africa is limited due to the strict legislation. The metabolites and nutritional value of Cannabis are influenced by growing conditions and soil type. Furthermore, the available literature has shown that Cannabis contains anti-nutritional factors that may affect feed intake or bioavailability and digestibility. Conclusions: Therefore, it is crucial to employ a processing method that can reduce anti-nutritional factors to promote the feed intake and growth rate of sheep. Fermentation, as a processing method, can reduce anti-nutritional factors found in Cannabis, which will make it a palatable alternative feed supplement for ruminants such as Dorper sheep. Overall, this review paper aimed to examine the available literature on the use of Cannabis as an alternative high-protein feed supplement for Dorper sheep in South Africa.

The Cannabis species is one of the potent ancient medicinal plants acclaimed for its medicinal properties and recreational purposes. The plant parts are used and exploited all over the world for several agricultural and industrial applications. For many years Cannabis spp. has proven to present a highly diverse metabolomic profile with a pool of bioactive metabolites used for numerous pharmacological purposes ranging from anti-inflammatory to antimicrobial. Cannabis sativa has since been an extensive subject of investigation, monopolizing the research. Hence, there are fewer studies with a comprehensive understanding of the composition of bioactive metabolites grown in different environmental conditions, especially C. indica and a few other Cannabis strains. These pharmacological properties are mostly attributed to a few phytocannabinoids and some phytochemicals such as terpenoids or essential oils which have been tested for antimicrobial properties. Many other discovered compounds are yet to be tested for antimicrobial properties. These phytochemicals have a series of useful properties including anti-insecticidal, anti-acaricidal, anti-nematicidal, anti-bacterial, anti-fungal, and anti-viral properties. Research studies have reported excellent antibacterial activity against Gram-positive and Gram-negative multidrug-resistant bacteria as well as methicillin-resistant Staphylococcus aureus (MRSA). Although there has been an extensive investigation on the antimicrobial properties of Cannabis, the antimicrobial properties of Cannabis on phytopathogens and aquatic animal pathogens, mostly those affecting fish, remain under-researched. Therefore, the current review intends to investigate the existing body of research on metabolomic profile and anti-microbial properties whilst trying to expand the scope of the properties of the Cannabis plant to benefit the health of other animal species and plant crops, particularly in agriculture.

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.

In southern African countries, production of indigenous leafy vegetables is commonly practiced at home garden and/or commercial level due to their significant contribution toward eradication of hunger, food insecurity, and malnutrition. Black nightshade (Solanum nigrum L.) is among African leafy vegetable (ALV) highly recognised for its pharmacological and nutritive benefits. Several research have shown that ALVs can be cultivated in the open field or greenhouses, however, little information is available on the changes of the agronomical parameters and mineral composition. The aim of the study was to compare the physiological parameters and mineral composition of nightshade grown in the open field vs. greenhouse cropping systems. The results of the study revealed high-leaf area and relative chlorophyll content in the open field conditions while plant height and the number of leaves were reportedly higher under the greenhouse system. Minerals elements such as magnesium, copper, manganese, iron, zinc, and aluminium were significantly higher in the open field cropping system, while greenhouse cultivation recorded higher sulphur and boron. Notably, no significant amount was observed in calcium, phosphorus, potassium, and sodium between open field and greenhouse system. Furthermore, a significant amount of total nitrogen was reported in the open field, however, no significant difference was observed in moisture and ash content for both cropping systems. In conclusion, black nightshade cultivated in open field provided higher leaf chlorophyll, leaf area, and trace elements compared to greenhouse cultivation while macro minerals concentration had no significant difference in both cropping systems.

Burkea africana is a tree found in savannah and woodland in southern Africa, as well as northwards into tropical African regions as far as Nigeria and Ethiopia. It is used as fuel wood, medicinally to treat various conditions, such as toothache, headache, migraine, pain, inflammation, and sexually transmitted diseases, such as gonorrhoea, but also an ornamental tree. The current study investigated the possible symbiotic relationship between B. africana trees and the C. forda caterpillars and the mutual role played in ensuring the survival of B. africana trees/seedlings in harsh natural conditions and low-nutrient soils. Deoxyribonucleic acid isolation and sequencing results revealed that the fungal species Pleurostomophora richardsiae was highly predominant in the leaves of B. africana trees and present in the caterpillars. The second most prominent fungal species in the caterpillars was Aspergillus nomius. The latter is known to be related to a Penicillium sp. which was found to be highly prevalent in the soil where B. africana trees grow and is suggested to play a role in enhancing the effective growth of B. africana trees in their natural habitat. To support this, a phylogenetic analysis was conducted, and a tree was constructed, which shows a high percentage similarity between Aspergillus and Penicillium sp. The findings of the study revealed that B. africana trees not only serve as a source of feed for the C. forda caterpillar but benefit from C. forda caterpillars which, after dropping onto the soil, is proposed to inoculate the soil surrounding the trees with the fungus A. nomius which suggests a symbiotic and/or synergistic relationship between B. africana trees and C. forda caterpillars.

Gonimbrasia belina (mopane worm) and Cirina forda caterpillars (Lepidoptera: Saturniidae) are mostly found in shrubs and trees, from where they are collected as larvae and are widely consumed across southern Africa by rural and increasingly urban populations. These caterpillars are among the most prominent, traded, and economically beneficial edible insects found in Western African countries, but also in South Africa, Zimbabwe, Botswana, and the Democratic Republic of the Congo. Over the years, these caterpillars have evolved from being part of the diet in various communities to playing a vital role in income generation. In addition, consumption of G. belina and C. forda caterpillars as potential food sources has gained momentum due to their potential for contributing to livelihoods and mitigating food security challenges across Africa while providing significant benefits to developing countries on a socio-economic and ecological level. Edible caterpillars serve as a good source of rich nutrients such as proteins, fatty acids, and micronutrients and can be used in formulating nutrient-dense complementary foods. However, limited information is available, specifically on different trees that serve as hosts to these caterpillars, as they depend on the leaves as their only source of food. In addition, the review aims to critique and document knowledge on the nutritional benefits, acceptance of the use of these caterpillars as food security, commercial value, and level of acceptance towards the utilization of caterpillars as food sources.

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.

Low soil fertility in savanna soils has been linked to low crop yields, with nitrogen being the most limiting factor in crop yield. Soil used in this pot experiment was obtained from Motshephiri village with low total N, low NO3− and high NH4+. A pot experiment was conducted in a greenhouse laid in a Randomized Complete Block Design with four treatments (1) control, (2) Bradyrhizobium japonicum inoculant, (3) superphosphate and (4) Bradyrhizobium japonicum inoculant + superphosphate). The superphosphate was applied at three different levels (45, 60 and 75 kg/ha). Lablab was cultivated in each treatment and the results of the study indicated that lablab growth significantly increased total N and NO3−, and reduced concentration NH4+ relative to the original soil herein referred to as pre-lablab growth. However, the N forms (total N, NO3− and NH4+) did not differ significantly amongst different levels of superphosphate with or without Bradyrhizobium japonicum inoculant. Lablab growth, proved to have a significant impact on both the soil macro (P, K, Ca, Mg, and Na) and micronutrient level (Fe, Mn, Cu, B and Cl) with the exception of Zn. This study suggests that lablab’s ability to rapidly boost soil N content, overall soil fertility in a short period of time without the use of superphosphate fertilizers or Bradyrhizobium japonicum inoculants makes it ideal for intercropping or rotating with non-leguminous crops that have a short growing season.

Burkea africana is a leguminous tree used for medicinal purposes, growing in clusters, on soils impoverished from most nutrients. The study aimed to determine the factors responsible for successful reproduction and establishment of the B. africana trees in nature, as all efforts for commercial production has been proven unsuccessful. An investigation was carried out to determine the metabolomic profile, chemical composition, and microbial composition of the soils where B. africana grows (Burkea soil) versus the soil where it does not grow (non-Burkea soil). 1H-NMR metabolomic analysis showed different metabolites in the respective soils. Trehalose and betaine, as well as a choline-like and carnitine-like compound, were found to be in higher concentration in Burkea soils, whereas, acetate, lactate, and formate were concentrated in non-Burkea soils. Liquid Chromatography-Mass Spectrometry analysis revealed the presence of numerous amino acids such as aspartic acid and glutamine to be higher in Burkea soils. Since it was previously suggested that the soil microbial diversity is the major driver for establishment and survival of seedlings in nature, Deoxyribonucleic acid (DNA) was extracted and a BLAST analysis conducted for species identification. Penicillium species was found to be highly prevalent and discriminant between the two soils, associated with the Burkea soils. No differences in the bacterial composition of Burkea and non-Burkea soils were observed. The variances in fungal composition suggests that species supremacy play a role in development of B. africana trees and is responsible for creating a supporting environment for natural establishment and survival of seedlings.