Assessment of the effects of NPK fertilizer on edible yield and agro-biological parameters in a cowpea–amaranth intercrop

Estimates indicate that food and nutritional demand in sub-Saharan African nutrient-poor soils will exceed the high population demand. Vegetables such as amaranth and cowpea are key in contributing to food and nutritional security. Fertilizers are used to mitigate low nutrient levels in soils. This study aimed to investigate the yield parameters of cowpea and amaranth vegetables. Methods: The experiment was designed with a 2 × 4 factorial treatment structure in a completely randomized design, with intercropping and fertilizer level as treatment factors and with four replications. Results and discussion: The biomass of amaranth and cowpea increased with increased fertilizer application up to the level of 100% nitrogen, phosphorus, and potassium (NPK) fertilizer. A measure of land utilization showed values greater than one. Crop comparison showed that cowpea was more aggressive, had higher actual yield loss, and was highly competitive compared to amaranth. More income could be obtained from intercropping. The research shows the benefits of fertilizer application in improving the biomass of amaranth and cowpea. Overall, the application of NPK fertilizer at levels up to 100%, based on the results of this study, resulted in higher biomass accumulation and improved intercropping indices

Antimicrobial Activity, Phenolic Content, and Cytotoxicity of Medicinal Plant Extracts Used for Treating Dermatological Diseases and Wound Healing in KwaZulu-Natal, South Africa

Medicinal plants used for wound healing and skin diseases are the key to unlocking the doors to combating problematic skin diseases as resistance of pathogens to pharmaceuticals and allopathic management continues to increase. The study aimed at investigating the antimicrobial efficacies, phenolic content and cytotoxicity effects of eleven medicinal plant extracts commonly used for treating skin conditions and wound healing in traditional medicine within KwaZulu-Natal. Eleven plant species were separated into different plant parts (bulbs, roots, leaves) and extracted with different solvents. The extracts were assessed for antimicrobial activity against six Gram-positive and seven Gram-negative bacterial strains and four fungi commonly associated with skin conditions using disc diffusion and microdilution techniques. The aqueous methanolic extracts were screened for phenolic content while cytotoxicity tests were performed on all extracts using the brine shrimp lethality and tetrazolium–based colorimetric (MTT) assays. Extracts from Aloe ferox, A. arborescens and Hypericum aethiopicum were the most active against almost all of the tested bacterial and fungal strains. All plant species exhibited some degree of antimicrobial activity. Total phenolic levels, flavonoids and tannins were also higher for A. ferox, followed by A. arborescens and H. aethiopicum respectively. The cytotoxicity results of all plant extracts were in the range of 90-100% survival after 24 h in the Brine shrimp assay. Extracts considered lethal would demonstrate > 50% shrimp death. The MTT cytotoxicity test yielded LC50 values of > 1 mg/mL on all extracts indicating that they are not cytotoxic. The observed antimicrobial efficacy demonstrated by some plant species and the general lack of cytotoxic effects on all the tested extracts presents some promising and beneficial aspects of these medicinal plant extracts in the treatment of skin diseases and wound healing. The two Aloe species and H. aethiopicum were among the best extracts that exhibited consistently good antimicrobial activity and warrants further investigations and possible isolation of bioactive principles

Effect of water regimes and harvest times on yield and phytochemical accumulation of two ginger species

In South Africa, both Commercial ginger (Zingiber officinale Roscoe) and African ginger (Siphonochilus aethiopicus (Schweinf.) BL Burtt) are significant medicinal plants. This study aimed to determine the effect of water regimes on the two-ginger species' phenolic content, antioxidant properties and yield at various harvest times. During the 2015/2016 and 2016/2017 crop seasons, a field experiment was conducted. The experiment used a randomised complete block design (RCBD) and included two ginger species, four irrigation regimes, and three replicate blocks. Four different levels of soil water availability (20-25%, 40-45%, 60-65%, and 80-85% maximum allowable depletion, MAD) were used. The severely stressed treatment (80-85% MAD) significantly increased total flavonoid and phenolic content and total antioxidant activity in both species, but the biomass yield was lower than the other treatments. The well-watered control (20-25% MAD) resulted in a significant increase in rhizome yield at different harvesting times but resulted in lower total flavonoid and phenolic content and total antioxidant activity for both species. However, the moderately stressed treatment (40-45% MAD) obtained a higher WUE, flavonoid, phenolic and antioxidant content without reducing yield significantly in both species. The results indicated a similar trend in phytochemical constituents for leaves and rhizomes. The species can be harvested seven to eight months after planting under open field conditions. The accumulation of phytochemicals is dependent on water regime, harvesting time, and plant part; growers should consider 40-45% MAD and harvest seven to eight months after planting when growing ginger species to save the scarce resource (water), high phytochemical content and rhizome yield.The University of Pretoria (UP), National Research Foundation (NRF), Oppenheimer Memorial Trust (OMT), Agricultural Research Council (ARC), Vegetable Industrial Medicinal Plants (VIMP) and Fortuna Company.https://www.elsevier.com/locate/scihorti2023-07-17hj2023Plant Production and Soil Scienc

Antimicrobial activity, phenolic content, and cytotoxicity of medicinal plant extracts used for treating dermatological diseases and wound healing in KwaZulu-Natal, South Africa

Medicinal plants used for wound healing and skin diseases are the key to unlocking the doors to combating problematic skin diseases as resistance of pathogens to pharmaceuticals and allopathic management continues to increase. The study aimed at investigating the antimicrobial efficacies, phenolic content, and cytotoxicity effects of 11 medicinal plant extracts commonly used for treating skin conditions and wound healing in traditional medicine within KwaZulu-Natal. Eleven plant species were separated into different plant parts (bulbs, roots, leaves) and extracted with different solvents. The extracts were assessed for antimicrobial activity against six Gram-positive and seven Gram-negative bacterial strains and four fungi commonly associated with skin conditions using disc diffusion and microdilution techniques. The aqueous methanolic extracts were screened for phenolic content while cytotoxicity tests were performed on all extracts using the brine shrimp lethality and tetrazolium-based colorimetric (MTT) assays. Extracts from Aloe ferox, A. arborescens, and Hypericum aethiopicum were the most active against almost all of the tested bacterial and fungal strains. All plant species exhibited some degree of antimicrobial activity. Total phenolic levels, flavonoids and tannins were also higher for A. ferox, followed by A. arborescens and H. aethiopicum, respectively. The cytotoxicity results of all plant extracts were in the range of 90-100% survival after 24 h in the brine shrimp assay. Extracts considered lethal would demonstrate >50% shrimp death. The MTT cytotoxicity test yielded LC50 values of >1 mg/mL on all extracts indicating that they are not cytotoxic. The observed antimicrobial efficacy demonstrated by some plant species and the general lack of cytotoxic effects on all the tested extracts presents some promising and beneficial aspects of these medicinal plant extracts in the treatment of skin diseases and wound healing. The two Aloe species and H. aethiopicum were among the best extracts that exhibited consistently good antimicrobial activity and warrants further investigations and possible isolation of bioactive principles.The University of KwaZulu-Natal and the National Research Foundation (NRF) of South Africa.http://www.frontiersin.orgam2016Paraclinical Science

Tilting Plant Metabolism for Improved Metabolite Biosynthesis and Enhanced Human Benefit

The immense chemical diversity of plant-derived secondary metabolites coupled with their vast array of biological functions has seen this group of compounds attract considerable research interest across a range of research disciplines. Medicinal and aromatic plants, in particular, have been exploited for this biogenic pool of phytochemicals for products such as pharmaceuticals, fragrances, dyes, and insecticides, among others. With consumers showing increasing interests in these products, innovative biotechnological techniques are being developed and employed to alter plant secondary metabolism in efforts to improve on the quality and quantity of specific metabolites of interest. This review provides an overview of the biosynthesis for phytochemical compounds with medicinal and other related properties and their associated biological activities. It also provides an insight into how their biosynthesis/biosynthetic pathways have been modified/altered to enhance production

Response of alectra vogelii benth to different crop root exudates

Aims: The aim of the study was to evaluate the effect of root exudates from cowpea, groundnut, maize, sorghum and pearl millet genotypes on the germination and attachment of Alectra vogelii. It also aimed to identify functional groups in the powdered root samples that stimulate A. vogelli germination. Study Design: In the laboratory, a Complete Randomised Design (CRD) replicated six times with six treatments; cowpea (IT18, CBC2 and CBC3); groundnuts (Nyanda), maize (PAN 413), sorghum (Landrace) pearl millet (Landrace) and a negative control (distilled water) were used. Place and Duration of Study: Department of Agronomy Laboratory, Midlands State University Gweru, Zimbabwe (19°25’S and 29°50’E), between March 2014 to May 2014. Methodology: To assess the germination and attachment of A. vogelii seeds, three seeds from each genotype were placed on a moistened filter paper in a petri dish with 0,01 g of preconditioned A. vogelii seeds. Identification of functional groups from the powdered root samples of all the crop genotypes using the FT-IR spectroscopy was also done. Results: Significant differences (P<.05) in the germination of A. vogelii were observed among the crop genotypes. All Cowpea genotypes and groundnut showed no statistical differences and had the highest germination percentages ranging between 72%-80%. The pearl millet landrace (62%) and groundnut (72%) also showed no statistical differences. Sorghum and maize allowed for low germination percentages (29.6% and 24.5%, respectively) Significant differences were noted among attachment counts (P<.05), however, with no statistical differences noted among the three cowpea varieties, which had the highest counts recorded on attachments (123-139 attachments). Significantly low counts on attachment were recorded in groundnut and all the cereals, ranging between 9-15 counts. The FT-IR spectra obtained from the root samples showed differences and similarities as revealed by the peaks (groundnut, CBC2 and PAN 413 - 8 peaks; IT 18, CBC3 and sorghum – 7 peaks; pearl Millet – 5 peaks). Conclusion: Groundnut and pearl millet genotypes caused effective suicidal germination of A. vogelii seeds and therefore can be used as trap crops in Integrated Weed Management Program. Maize and sorghum did not effectively support germination or attachment. Use of High Performance Liquid Chromatography (HPLC) and mass spectrometry to identify and quantify the strigolactones in each genotype is highly recommended

Acetylcholinesterase inhibition and antibacterial activity of Mondia whitei adventitious roots and ex vitro-grown somatic embryogenic-biomass

Mondia whitei (Hook.f.) Skeels is an important endangered medicinal and commercial plant in South Africa. In vitro propagation systems are required for biomass production and bioactivity analysis to supplement wild resources/stocks. Adventitious roots from somatic embryogenic explants using suspension culture and ex vitro-grown plants produced via somatic embryogenesis were established using different plant growth regulator treatments. The adventitious root biomass and different parts of ex vitro-grown and mother plants were used to investigate the potential for acetylcholinesterase (AChE) and antibacterial activities. Adventitious roots derived from 2.5 µM indole-3-acetic acid (IAA) treatments and ex vitro-grown plants derived from meta-topolin riboside (mTR) and IAA treatments gave the best AChE and antibacterial activities. The in vitro-established M. whitei and ex vitro biomass have comparable ability to function as inhibitors of acetylcholinesterase and antibacterial agents, and can be used as potent bioresources in traditional medicin

Anti-Oxidative and Cholinesterase Inhibitory Effects of Leaf Extracts and Their Isolated Compounds from Two Closely Related Croton Species

A comparative evaluation of the antioxidant and acetylcholinesterase inhibitory activity of the leaf extracts of Croton gratissimus and Croton zambesicus (subgratissimus) and compounds isolated from the extracts was carried out to determine their potential and suitability or otherwise as a substitute for each other in the management of oxidative and neurodegenerative conditions. Different antioxidant assays (DPPH, FRAP, β-carotene-linoleic and the lipid peroxidation models) and the microplate assay for acetylcholinesterase (AChE) inhibition were carried out separately to study the activities of the crude leaf extracts and four solvent fractions from each of the two Croton species. Bioassay guided fractionation was used to target antioxidant constituents of the crude extracts and ethyl acetate fractions of 20% aqueous methanol extract of C. gratissimus on silica gel and Sephadex LH-20 columns resulted in the isolation of kaempferol-3-O-β-6&#039;&#039;(p-coumaroyl) glucopyranoside (tiliroside, 2), apigenin-6-C-glucoside (isovitexin, 3) and kampferol (4). The extract of C. zambesicus yielded quercetin-3-O-β-6&#039;&#039;(p-coumaroyl) glucopyranoside-3&#039;-methyl ether (helichrysoside- 3&#039;-methyl ether, 1), kaempferol-3-O-β-6&#039;&#039;(p-coumaroyl) glucopyranoside (tiliroside, 2) and apigenin-6-C-glucoside (isovitexin, 3). Three of the isolated compounds and their different combinations were also included in the bioassays. In all the assays performed, the antioxidant capacity and AChE inhibitory effects of C. zambesicus extracts were weaker than those of C. gratissimus. This suggests that C. gratissimus may not be substituted by C. zambesicus, despite the similarity in some of their constituents. Generally, the combinations made from the isolated compounds showed better activities in most of the assays compared to the individual isolated compounds. This suggests mechanisms such as synergism and/or additive effects to be taking place. This study established low, moderate and high antioxidant activities as well as AChE inhibitory effects by the crude extracts, fractions, compounds and compound combinations. This means some of the extracts, isolated compounds and compound combinations could be useful in the management of neurodegenerative conditions and serve as sources of natural neurodegenerative agents

Productivity of Selected African Leafy Vegetables under Varying Water Regimes

African leafy vegetables (ALVs) are nutrient dense and can contribute to crop and dietary diversity, especially in water-stressed environments. However, research on their productivity under limited water availability remains scant. The objective of the study was to evaluate growth, physiology and yield responses of three ALVs (Vigna unguiculata, Corchorus. Olitorius and Amaranthus cruentus) and a reference vegetable (Beta vulgaris var. cicla) to varying water regimes [30%, 60% and 100% of crop water requirement (ETc)]. Field trials using a randomised complete block design, replicated three times, were conducted over two summer seasons, 2015/16 and 2016/17. Leaf number, plant height, chlorophyll content index (CCI), chlorophyll fluorescence (CF), and yield were measured in situ. For A. cruentus and C. olitorius, water stress (30% ETc) was shown to produce a lower yield, although leaf number, plant height and chlorophyll content index were unaffected, while for B. vulgaris, leaf number and yield were reduced by water stress. For V. unguiculata, CF, CCI, plant height, leaf number, and yield were not affected by water stress, indicating its suitability for production in water scarce environments. Using 60% ETc was suitable for the production of A. cruentus, C. olitorius and B. vulgaris var. cicla, whereas 30% ETc is recommended for V. unguiculata. The yield results of V. unguiculata indicate that it performs better, while the yield of A. cruentus and C. olitorius is comparable to that of B. vulgaris under similar conditions, indicating potential for marginal production

Scribbling the cat : a case of the “miracle” plant, Moringa oleifera

This paper reviews the properties of the most cultivated species of the Moringaceae family, Moringa oleifera Lam. The paper takes a critical look at the positive and the associated negative properties of the plant, with particular emphasis on its chemistry, selected medicinal and nutritional properties, as well as some ecological implications of the plant. The review highlights the importance of glucosinolates (GS) compounds which are relatively unique to the Moringa species family, with glucomoriginin and its acylated derivative being the most abundant. We highlight some new research findings revealing that not all M. oleifera cultivars contain an important flavonoid, rutin. The review also focuses on phenolic acids, tannin, minerals and vitamins, which are in high amounts when compared to most vegetables and fruits. Although there are numerous benefits of using M. oleifera for medicinal purposes, there are reports of contraindications. Nonetheless, we note that there are no major harmful e ects of M. oleifera that have been reported by the scientific community. M. oleifera is suspected to be potentially invasive and moderately invasive in some regions of the world because of its ability to grow in a wide range of environmental conditions. However, the plant is currently classified as a low potential invasive species and thus there is a need to constantly monitor the species. Despite the numerous benefits associated with the plant, there is still a paucity of data on clinical trials proving both the positive and negative e ects of the plant. We recommend further clinical trials to ascertain the properties associated with the plant, especially regarding long term use.This study was funded by the Department of Science and Technology—Indigenous Knowledge System -based Tech Innovation, Pretoria, and the National Research Foundation (NRF) South Africa.The Department of Science and Technology—Indigenous Knowledge System-based Tech Innovation, Pretoria, and the National Research Foundation (NRF) South Africa.https://www.mdpi.com/journal/plantsam2020Physiolog