Bambara groundnut (Vigna subterranea L. Verdc) is the second most important indigenous food legume in Africa. The aim of this study was to evaluate plant growth, N 2 fixation, N contribution, C accumulation, and plant water relations of Bambara groundnut grown in 26 farmers' fields in Mpumalanga Province of South Africa. The data revealed marked (p ≤0.05) differences in plant dry matter (DM) yield, N concentration and content, δ

Nanoparticles possess several properties, such as antimicrobial, anti-inflammatory, wound healing, catalytic, magnetic, optical, and electronic properties, that have allowed them to be used in different fields. Among them, zinc oxide (ZnO) has received copious consideration due to its technological and medicinal applications. Plant-mediated synthesis of ZnO nanoparticles has provided a cost-effective and eco-friendly method. Therefore, the objective of the study is to assess the effect of the precursor concentration and silver and cerium doping on the optical properties of ZnO nanoparticles synthesized via a green process using bush tea leaf extract as the chelating agent. Zinc nitrate hexahydrate was used as the precursor. Quasi-spherical-shaped ZnO nanoparticles were obtained with an average crystallite size ranging between 24.53 and 63.02 nm. The crystallite size was found to decrease with the increase of precursor concentration at 43.82 nm (0.05 g), 37.25 nm (0.10 g), 26.53 nm (0.50 g), and 24.53 nm (1 g); thereafter, the size increases with an increase in precursor concentration. The optimum precursor concentration was 1 g with the smallest grain size and a high purity level. The increase in annealing temperature induced an increase in the crystallite size of ZnO nanoparticles from 24.53 nm (600 °C) to 34.24 nm (800 °C), however, increasing the level of purity of the nanopowders. The band gap energies were 2.75 and 3.17 eV as calculated using the Tauc plot with variations due to the precursor concentrations. Doping with both silver and cerium increased the band gap of ZnO nanoparticles up to 3.19 eV and the increase in annealing temperature slightly augmented the band gap energy from 3.00 and 3.16 eV, respectively. Hence, doping with Ag and Ce induced the formation of nanorods at higher concentrations. This study successfully demonstrated that the natural plant extract of bush tea can be used in the bioreduction of zinc nitrate hexahydrate to prepare pure ZnO nanoparticles, thus extending the use of this plant to the nano producing industry.

Bush tea (Athrixia phylicoides DC.) is a popular medicinal South African indigenous plant and it has been used for many decades as a health beverage and medicine. The objective of the study was to profile metabolites for assessment of quality of bush tea (A. phylicoides DC.) subjected to different pruning levels. Treatments consisted of untreated control, top-branch pruning, middle pruning, and basal pruning arranged in a randomized complete block design (RCBD) using 10 single trees as replications. The liquid chromatography quadrupole time-of-flight mass spectrometry (LC–QTOF–MS) was carried out to annotate the bush tea metabolites present in bush tea. Orthogonal partial least square-discriminatory analysis (OPLS-DA) from 1H nuclear magnetic resonance (NMR) revealed a separation between the basal, middle, top pruning, and the unpruned bush tea plants. The pruned (top) and unpruned tea plants, exhibited higher levels of metabolites than the basal and middle pruned. Pruning bush tea showed a significant effect on accumulation of secondary metabolites and thus could enhance bush tea quality. The study successfully annotated 28 metabolites (compounds), which elucidated canonical differences in pruning treatment of bush tea, as validated through multivariate analysis. Top pruning (apically pruned) resulted in improved metabolite accumulation than other treatment and can be recommended in bush tea cultivation. Future studies to enhance vegetative enhancement after pruning will be evaluated.

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Deterioration of soils over the years has led to a decline in crop yields and nutritional qualities, resulting from the oversupply of conventional fertilizers, which are unsustainable, costly and pose a threat to the environment. Nanoparticles are gaining a reputation in the field of agriculture for the remediation of soil degradation in a sustainable way. Recently, they have been recognized as potential fertilizers with properties that make them more absorbable and readily available for plant use than their bulk counterpart. However, there is less literature elaborating on the use of nanoparticles as agro-inputs for crop nutrition and protection. This review, therefore, provides insights into the application of nanoscaled nutrient elements such as silver, zinc, copper, iron, titanium, magnesium and calcium as fertilizers. In addition, the review explains the need for utilizing green synthesized nanomaterials as one of the ways to palliate the use of environmentally toxic chemicals in the cropping system and discusses the various benefits of nanoparticles, ranging from plant growth stimulation to defence against pathogens.