Selected micronutrients effect on growth, development, and yield of black nightshade (Solanum nigrum)

Abstract Black nightshade (Solanum nigrum) is an important indigenous leafy vegetable consumed in sub‐Saharan Africa. The species is an important source of micronutrients for medicinal purposes. A controlled experiment was conducted at the University of KwaZulu‐Natal, Pietermaritzburg, South Africa, to investigate the effect of zinc and boron applications on the growth, development, and yield of black nightshade. Each micronutrient (zinc and boron) was applied at five different concentrations, namely, 100 (T1), 200 (T2), 300 (T3), 400 (T4), and 500 (T5) ppm, including a control (T0) (distilled/high pressure liquid chromatography water spray), giving a total of six treatments. Treatments were arranged in a complete randomized design (CRD) with three replications, giving a total of 18 experimental units (pots). After 14 days of transplanting, the treatments were applied through foliar spraying three times over 24 h with an 8‐h interval between each spraying event. Data collection started 14 days after transplanting, and thereafter, measurements were taken fortnightly. At harvest (70 days after transplanting), fruit number, fresh shoot weight, dry shoot weight, root fresh mass, and root dry mass were determined. The results showed significant growth and yield differences with respect to the different concentrations of zinc and boron (p < 0.05). The application of 500 ppm of boron performed significantly better than all other treatments, viz., zinc, and control across the measured variables (p < 0.05). Therefore, it is concluded that the application of boron at 500 ppm was found to be effective in enhancing plant growth and higher fruit yield (45 fruits) of black nightshade

Response to various water regimes of the physiological aspects, nutritional water productivity, and phytochemical composition of bush tea (Athrixia phylicoides DC.) grown under a protected environment

The influence of water regimes on plants is crucial for integrating bush tea (Athrixia phylicoides DC.) into strategies in Sub-Saharan Africa to tackle food and nutritional insecurity by considering physiological aspects, nutritional yield, nutritional water productivity, and metabolite composition. The objective of the study was to determine the physiological aspects, including leaf gas exchange and chlorophyll fluorescence, nutritional yield, nutritional water productivity, and metabolite composition of bush tea under varying water regimes. The tunnel experiment was laid out in a randomized complete block design (RCBD) with treatments consisting of three water regimes: 100% of crop water requirement (ETa), 30% of ETa, and a control (no irrigation), all replicated three times. The morphological aspects were recorded on a weekly basis. However, yield, nutrient content, nutritional water productivity (NWP), and phytochemical composition were determined at harvest. The phytochemical analysis by liquid chromatography mass spectrometry (LC-MS), coupled with visualization of the detected chemical spaces through molecular networking, indicated Athrixia phylicoides DC. to be rich in various bioactive compound derivatives, including methyl chlorogenate, flavonoids, tartaric acid, caffeoylquinic acid, and glutinane. The results showed that 30% ETa enhanced plant growth, nutrient content, and nutritional water productivity compared to other water treatments. Nevertheless, 100% ETa yielded more (95.62 kg ha−1) than 30% ETa (60.61 kg ha−1) and control (12.12 kg ha−1). The accumulation of chlorogenic acids was higher under 30% ETa compared to 100% ETa and control. Therefore, this study is the first to determine the accumulation of various bioactive compounds in bush tea leaf extracts under varying water regimes. This confirms that in areas with low water availability, bush tea is well adapted for production without limiting nutrients

Investigating the influence of varying water regimes on the growth and development and nutritional water productivity of bush tea (Athrixia phylicoides DC.)

Bush tea (Athrixia phylicoides DC.) is an indigenous shrub of South Africa known for its medicinal properties. However, due to a lack of comprehensive information to develop suitable irrigation management strategies, the cultivation of bush tea is currently limited to small‐scale operations. Considering this limitation, the current research investigated the effect of water regimes on the growth and development, yield, and nutrient content along with its nutritional water productivity (NWP) under field conditions. The treatment consisted of a crop water requirement (ETa) of 100%, 30%, and the control (stress) in a complete randomized block design (CRBD). Each treatment was replicated three times to ensure robustness and accuracy of the findings. Results demonstrated that the highest gravimetric moisture content readings were found in the control treatment and the lowest in the 100% treatment. Conversely, the 30% ETa treatment significantly (p &lt; 0.05) impacted bush tea's growth, development, productivity, and NWP. However, it was observed that the 100% ETa treatment resulted in a higher biomass yield (259.1 kg/ha) compared to the 30% ETa treatment (171.2 kg/ha) and control (stress) (68.2 kg/ha). The water productivity exhibited notable differences across the varying water regimes. These findings contribute valuable insights for developing appropriate irrigation management strategies to overcome existing limitations in the scale of bush tea production. The research lays the groundwork for future studies and practical applications aimed to foster the sustainable cultivation of bush tea in South Africa.Water Research Commission, Grant/Award Number: C2020/2021-00420Urban Agriculture &amp; Regional Food System