ABSTRACT Sclerocarya birrea (marula) trees are important components of dry and semi‐dry African savanna environments due to their ecological and economical importance, including carbon storage. However, functional characteristics of these dioecious trees, such as their photosynthetic rates, remain largely unstudied. We quantified the diurnal cycle in leaf‐level net photosynthetic rate ( A ), stomatal conductance ( g sw ) and transpiration ( E ) in sun and shade leaves of male and female individuals of 14 Sclerocarya birrea trees in a northern Namibian semi‐arid agroforestry system and explained the observed trends by three environmental drivers (light, temperature and humidity). A generalised additive model with a thin‐plate regression spline smoother was applied to describe non‐linear diurnal variation in A , g sw and E . Results revealed a pronounced pre‐midday decline in A for sun leaves, from 5.5 μmol CO₂ m −2 s −1 in the morning to 2.4 μmol CO₂ m −2 s −1 in the late afternoon, while shade leaves showed a continuous decrease from 3.0 to 1.8 μmol CO₂ m −2 s −1 . Correspondingly, g sw declined from 0.07 to 0.04 mol m −2 s −1 , and E from 0.0012 to 0.0008 mol m −2 s −1 between morning and afternoon hours for sun leaves. Male trees exhibited higher A , g sw and E than females, suggesting secondary sexual dimorphism in gas‐exchange traits. Light was the best predictor of net photosynthetic rate and transpiration, whereas temperature was the best predictor of stomatal conductance. These findings highlight the complex interplay between environmental factors, leaf position and tree‐specific traits in shaping the photosynthetic performance of Sclerocarya birrea . Consequently, this knowledge enables better‐informed management and conservation strategies for this key savanna species.

Introduction The choice of growth media is an important aspect of nurseries, as it affects the success and quality of the seedling establishment. A greenhouse experiment was conducted to investigate the effects of soil amendment on germination and growth of marula. Methods The soil was amended with cattle manure at the following ratios: T1 (5 parts topsoil: 1-part sand: 4 parts cattle manure), T2 (6 parts topsoil: 1 part sand: 3 parts cattle manure), T3 (4 parts topsoil: 2 parts sand: 4 parts cattle manure), T4 (5 parts topsoil: 2 parts sand: 3 parts cattle manure), T5 (4 parts topsoil: 4 parts sand: 2 parts cattle manure), T6 (topsoil only), T7 (Cattle manure only), and T8 (sand only). A randomized complete block design (RCBD) was used and replicated four times. Results The effects of soil amendment on germination were highly significant (p < 0.001) at two weeks, three weeks, and four weeks after planting. Marula seeds that were grown in a medium of cattle manure only showed the highest final germination percentage (92.25%) after six weeks. Plant height was also significantly influenced by growth media at eight (p < 0.001) and 12 (p < 0.05) weeks after planting. The effects of growth media were also highly significant (p < 0.001) on the germination index, germination rate, and vigor index. Significant differences (p < 0.05) in root lengths were recorded 90 days after planting. Discussion From these results, it can be concluded that soil amendment with cattle manure enhances germination and early seedling growth and development of marula.

Identifying the key products of mopane woodlands, the perceived abundance of species, and the associated use values have important implications for rural communities and the sustainable use of mopane woodlands. This study examined local perceptions of tree species abundance and their associated use-values across four communities in the Mopani District, South Africa. The semi-structured questionnaire and key informant interviews were used to collect the data. The data were analyzed using descriptive statistics, the Friedman test, the Smith Salience Index, Kendall’s W, Pearson correlation, and the Fidelity test. There was a very strong level of agreement (W = 0.83) among the communities regarding the perceived abundance of tree species, and this agreement was statistically significant (χ2 = 19.85, p < 0.05). The Colophospermum mopane, Sclerocarya birrea, and Combretum imberbe are the most perceived abundant species in the study areas and have high value. The tree species with high use-value showed a positive correlation with the perceived abundance of tree species, conforming to the study’s ecological apparency hypothesis. The more apparent species had more use value and perceived abundance.

Development, nutritional evaluation, and consumer acceptability of non-alcoholic fermented beverages made from Sclerocarya birrea (Marula) and provitamins A biofortified maize

ABSTRACT Introduction Unsustainable agricultural practices contribute to biodiversity loss globally, calling for efforts to reconcile agricultural productivity and biodiversity conservation in agroecosystems. However, the potential benefits of Sclerocarya birrea in drylands agroforestry are not documented. This study investigated the effects of S. birrea subspecies birrea on soil chemical properties, sorghum productivity and nutritional quality in Northwestern drylands of Tanzania. Materials and Methods Field experiments were conducted in the 2019/20 and 2020/21 farming seasons with three treatments (i) the presence of marula tree, (ii) tree sex nested within tree treatment, and (iii) control (no tree). Thus, the treatments were arranged in a nested block design (NBD) experimental design. Results The soil pH, organic carbon (OC), total nitrogen (TN), electrical conductivity (EC), manganese (Mn), calcium (Ca), cation exchange capacity (CEC), and potassium (K) were significantly ( p < 0.05) higher in soils under the tree canopies than in no tree during the 2019/20 farming season. Similarly, OC, EC, Ca, CEC, Mg, and K were significantly ( p < 0.05) higher in soils under the tree canopies than in no tree during the 2020/21 farming season. Sorghum plants basal diameter, stem height, chlorophyll concentration, and sorghum grain yields were significantly ( p < 0.05) higher under trees canopies than in plots with no trees. Sorghum grain yields were 3 359.38 kg/ha and 3 305.21 kg/ha under tree canopies while in no tree plots were 2 146.43 kg/ha and 2 050.00 kg/ha for 2019/20 and 2020/21, respectively. Iron concentration in sorghum grains from sorghum plants grown under tree canopies was higher than those away from the canopies, but no significant differences in proximate composition and other minerals concentration in grains. Conclusion Subsp. birrea improved soil chemical properties, and sorghum yields. Thus, it is a potential tree for agroforestry in drylands.

Innovative Bi-functional carbon materials synthesis and characterization from hulls and zest of sclerocarya birrea (A. Rich) for possible biomedical applications

The increasing popularity and use of medicinal plants by breastfeeding mothers to promote lactation continue to draw the attention of healthcare professionals and other scientists in knowing more about the composition, benefits, and potential adverse effects of these plants after consumption. The objectives of this review were to assess the chemical constituents and toxicity profile of medicinal plants used as galactagogues in Niger republic. Relevant data about the plant species used to promote lactation were extracted from published literatures which were searched through refutable scientific databases or platforms. Eighty two (82) out of One hundred and fifty three (153) published studies were selected and reviewed for the purpose. Evaluated plant species include Faidherbia albida, Acacia nilotica, Adansonia digitata, Balanites aegyptiaca, Boscia salicifolia, Cucumis ficifolius, Euphorbia aegyptiaca, Gisekia pharnacioides, Guiera senegalensis, Prosopis africana, Sclerocarya birrea, Tephrosia purpurea. Several reports have emphasized the richness of these plants species in various chemical constituents with phenolic acids and flavonoids as the most representative. Slight to deleterious side effects that could arise after the ingestion of certain plant species in experimental animals were recorded. Only two plant species were reported to produce a positive effect on promoting milk production. None of the cited plants have been evaluated in clinical studies involving lactating women as subject of study. Globally, the findings highlighted that there are some significant gaps in both preclinical and clinical studies to support the ethnopharmacological indication of these plant species. Locally-based clinical studies are urgently needed to identify and confirm the efficacy and safety of these plants for the benefit of lactating mothers.

Abstract I aimed to evaluate the role of traditional ecological knowledge (TEK) in managing the collection of non-timber forest products (NTFPs) in Muyexe and Matiyane, located in Limpopo Province, South Africa. To do this, I gathered data from tribal authorities and local communities through semi-structured face-to-face interviews, involving a total of 148 respondents from both villages. Participants were selected using a combination of purposive and snowball sampling methods. Data were analyzed with thematic content analysis. My study identified two main categories of TEK used in managing NTFP harvesting: TEK in the form of rules and regulations, and TEK in the form of taboos. The enforcement of laws and sanctions for violations emerged as the most important factor affecting the effectiveness of local institutions in managing NTFP collection. I emphasize that, beyond modernization, agreed-upon rules and taboos governing resource collection play vital roles in conserving mopane trees (Colophospermum mopane) and marula trees (Sclerocarya birrea subsp. caffra). The findings suggest a need for adaptable local management systems that strengthen TEK among communities involved in managing or overseeing NTFP collection, thereby promoting long-term livelihood security and conserving marula and mopane woodland communities.

Photoaging, caused by prolonged UV exposure, accelerates skin aging through oxidative stress, collagen degradation, and inflammation. With growing consumer demand for natural and sustainable anti-aging solutions, marula oil has gained attention for its potential in mitigating photoaging. Derived from Sclerocarya birrea, marula oil is rich in fatty acids (oleic and palmitic acids) and antioxidants like vitamin C and E. This review investigates marula oil’s bioactive components and their mechanisms of action in alleviating photoaging, focusing on its moisturizing, antioxidant, and photoprotective properties. Moreover, clinical studies examine its ability to improve skin hydration, enhance barrier function, and inhibit enzymes associated with collagen degradation. Despite its promise as a cosmeceutical, long-term studies are necessary to explore its sustained efficacy, molecular pathways, and potential synergy with other natural ingredients.

In the search for environmentally friendly corrosion inhibitors, medicinal plants rich in various phytochemicals present promising options due to their natural ability to adsorb onto metal surfaces, forming protective barriers against corrosive agents. This study examines the phytochemical profile of the ethanolic extract of Sclerocarya birrea using Fourier Transform Infrared Spectroscopy (FTIR), Ultraviolet-Visible (UV-Vis) spectroscopy, and Gas Chromatography-Mass Spectrometry (GC-MS). The UV-Vis spectrum displayed distinct absorption peaks characteristic of the extract’s components. FTIR analysis confirmed the presence of functional groups associated with alkanes, alkenes, phenols, amines, aromatics, esters, ketones, and aldehydes. GC-MS detected 17 phytochemical compounds, including notable components such as γ-sitosterol (39.44%), l-(+)-ascorbic acid 2,6-dihexadecanoate (17.37%), pagicerine (14.66%), hexadecanoic acid derivatives (10.45%), octadecanoic acid (4.34%), and phytol (3.46%). These compounds are known for their medicinal properties and chemical structures that support effective corrosion inhibition. The phytochemicals primarily contribute to corrosion protection by adsorbing onto metal surfaces, creating protective films that impede both anodic and cathodic reactions, thus reducing metal dissolution and increasing resistance. The detailed phytochemical analysis provides a solid basis for further research into S. birrea as a sustainable and effective corrosion inhibitor for various metals in different corrosive environments. This work emphasizes the extract’s potential as an environmentally friendly alternative to traditional synthetic inhibitors.

Nutritional and physiological impact of dietary marula (Sclerocarya birrea ssp. caffra) kernel cake as a soybean meal replacement in Jumbo quail: implications for meat quality and consumer health

Sclerocarya birrea (A.Rich.) Hochst and Cassia abbreviata (Oliv) are frequently harvested in Africa, yet little is known about harvesting implication. To fill this gap, we conducted surveys to assess perceptions of their uses, and how locality, gender, education, and age influence ecological knowledge, awareness of harvesting implications and willingness to conserve among rural and peri-urban populations and χ2 was used to test for associations. We used two-way ANOVA to compare tree density, diameter, height, and stump density, and one-way ANOVA for plant use values across study sites. No association observed between locality and species use; however, gender significantly affected the use of S. birrea (P < 0.05). Educational level influenced S. birrea usage but not C. abbreviata, and age had no influence (P > 0.05). Locality, gender, and education did not impact use values, while age did. Rural areas exhibited higher ecological knowledge and awareness of harvesting implications than peri-urban areas, while gender, educational level and age influenced ecological knowledge and awareness of harvesting implications, with males and tertiary education category more aware of harvesting implications. C. abbreviata had a higher tree density in rural areas, while S. birrea density was stable across locations. No significant differences in average height or stem diameter for either species. S. birrea exhibited higher stump density in peri-urban areas. This research highlights the need for further studies on the ecological impacts of harvesting these species, emphasising management challenges and the necessity for adaptable conservation strategies for C. abbreviata.

The Ferlo, a semi-arid Sahelian region of Senegal, experiences intense heat for five months (February to June), with temperatures exceeding 45°C, and a milder climate for seven months (July to January) thanks to rainfall. This area is being heavily impacted by climate change. Low rainfall, combined with human activities, is affecting the development of plant cover, particularly woody species, which are essential to the local population as a source of food for livestock during the dry season. The main objective of this study is to provide information on the dendrometric characteristics of a Sclerocarya birrea woody stand, in order to better conserve biodiversity and ecosystem services in the Ferlo (Amaly, Widou Thiengoly, Tessékéré and Labgar). We counted 31 species in 23 genera and 15 families, with the Fabaceae (25.81%), Combretaceae (19.35%), Apocynaceae (12.90%) and Malvaceae (6.45%) being the most represented. The genus Acacia is the most common. Almost all the species observed are Phanerophytes and around 68% of the species recorded are African. The study shows that the shrub stratum dominates the environment, while the woody stratum is gradually evolving, with a strong presence of young individuals and good regeneration. However, the population of S. birrea is following an opposite dynamic, with mainly large-circumference individuals, indicating an ageing and vulnerable population. The analysis reveals instability in the S. birrea population and almost no regeneration. It is therefore essential to develop regeneration, reforestation and monitoring strategies to improve the conservation of biodiversity and ecosystem services.

Wild edible fruits are important for ensuring food and nutritional security, especially in developing countries like South Africa. Globally, wild edible fruits are widely distributed, and they are consumed in different parts of the world; however, they are undervalued. This systematic review consolidates existing knowledge addressing the utilization of wild edible fruits, and their nutritional benefits. A total of 74 wild edible fruit species belonging to 29 families found in South Africa were documented in this study. The nutritional composition was reported only in 41 (55.4%) fruit species. The Anacardiaceae family had the most cited species (n = 11) (14.86%), followed by the Moraceae (n = 6) (8.1%), and Cucurbitaceae and Ebenaceae, of which each had five species, each contributing 5.4% to the total documented species. Sclerocarya birrea. (A.Rich.) Hochst., Mimusops zeyheri Sond., and Strychnos spinosa Lam. are three of the most important wild fruit species contributing to food and nutritional security. This review revealed that there is a dearth of literature studies that have substantially documented the contribution of wild edible fruits in food and nutritional security. In this regard, a study on ethnobotanical evaluation incorporating wild edible fruits used by local people could significantly provide insights and enhance our understanding of indigenous and technological knowledge that could be utilized to strengthen rural food security.

Breastfeeding is recognized as an effective way to save children’s lives. Nigerien breastfeeding mothers with insufficient milk production traditionally use medicinal plants to enhance milk yield, despite of absence of scientific reports confirming the evidence-based safety and efficacy of these practices. The aim of this study is to review the ethnomedicinal knowledge about the use of medicinal plants to promote lactation in breastfeeding mothers by Nigerien peoples, and to assess their evidence-based toxicological and chemical studies reported across the world. Relevant data about the plant species used to promote lactation were extracted from published or unpublished valuable reports of ethnobotanical surveys conducted in Niger for a comprehensive review. Six studies were reviewed. A total of thirteen (13) plant species belonging to 11 families were recorded as being used as galactagogues by Nigeriens. This review poined out three species including Sclerocarya birrea, Caralluma longidens and Guiera senegalensis to be the most cited. Using plants to promote lactation in breastfeeding mothers is a very common practice in Niger republic. However, there are no scientific reports based on laboratory studies which could justify the rational use of these plants. Further local studies are urgently needed to confirm the efficacy and safety of these plants.

Sclerocarrya birrea (Marula) is one of the underutilized wild edible fruit tree species that is grown in Far North Cameroon. The present study investigated the effect of different drying methods on the proximate composition, mineral content, and lipid oxidation of marula kernels consumed in Far-North Cameroon. Sun drying, oven drying, and roasting were employed. The proximate analysis was performed using AOAC methods. Lipid oxidation was evaluated by measuring free fatty acid (FFA), iodine value (IV), peroxide value (PV), p-Anisidine value (p-AV), and thiobarbituric reactive substances (TBARS). Results showed that raw marula kernel contains 7.31% moisture, 4.15% ash, 23.19% proteins, 47.73% lipids, 8.90% carbohydrates, and 7.49% crude fiber. Marula kernels are good sources of phosphorous (P: 1311.88 mg/100g), calcium (Ca: 1144.13 mg/100g), potassium (K: 983.87 mg/100g), zinc (Zn: 7.60 mg/100g), and iron (Fe: 7.04 mg/100g). All the processing methods significantly increased (P<0.05) the ash, protein, lipid, and carbohydrate contents of the marula kernel. An increase in Ca, P, K, magnesium (Mg), Fe, and Zn were also noted. During processing, FFA, PV, p-AV, and TBARS increased significantly (P<0.05), while IV decreased. Oven drying at 80 °C was the best method, given the high protein content, while roasting for 10 min provided the highest lipid content. The oven-dried sample at 40 °C was found to have the best oil qualities.

Diabetes mellitus, characterized by chronic hyperglycaemia, remains a major global health burden. Limitations of conventional therapies have led to growing interest in medicinal plants like Sclerocarya birrea (A. Rich.) Hochst. widely used in African ethnomedicine. Though prior research has focused more on the stem bark, studies on the leaves, considered more sustainable and traditionally relevant, are still lacking in vivo data. This study assessed the antidiabetic potential of a hydroethanolic leaf extract of Sclerocarya birrea in Wistar rats. The extract was tested at 25-200 mg/kg in an oral glucose tolerance test (OGTT), and at 100-400 mg/kg in normoglycemic and high fructose-fed, streptozotocin (STZ)-induced type 2 diabetic rats over 21 and 28 days, respectively. Fasting blood glucose, insulin, glycated haemoglobin (HbA1c), glucose transporter type 4 (GLUT4), haematological and biochemical parameters, and histopathological changes in key organs were evaluated. In the OGTT, the extract significantly reduced postprandial blood glucose at 100 and 200 mg/kg starting from 60minutes post-glucose load (p < 0.05). In normoglycemic rats, repeated administration over 21 days led to a dose-dependent and statistically significant reduction in fasting blood glucose beginning on day 14 and sustained through day 21 (p < 0.01). In diabetic rats, fasting blood glucose levels were significantly reduced from day 7 onward, with 400 mg/kg producing effects comparable to glibenclamide by day 28 (p < 0.01). Insulin, GLUT4, and HbA1c levels were not significantly altered (p > 0.05). Haematological and biochemical parameters remained within normal ranges, and histopathological examination showed preservation of pancreatic and renal tissues in treated groups. Sclerocarya birrea leaf extract significantly lowers blood glucose in both normoglycemic and diabetic rats without adverse effects, supporting its potential as a safe plant-based option for diabetes management. Further research is warranted to clarify its mechanisms and long-term impact.

South African indigenous fruits remain largely underutilized, with limited research conducted on their potential for developing novel products. Indigenous fruits have unique appearances, flavors, and nutritional values. However, these fruits have a short fruit season. Processing and new product development can ensure longer shelf life and income generation through value-adding. This study aimed to evaluate the potential of underutilized indigenous fruits Carissa edulis (simple-spined num-num), Dovyalis affra (Kei-apple), Dovyalis longispina (Natal apricot), Englerophytum magalismontanum (stamvrug), and Sclerocarya birrea (marula) for jam production. Due to genetic variation among Kei-apple fruits, two selections were included in the study. The study also investigated the impact of storage time and temperature on the quality of the jams. Physicochemical analyses were conducted on the fruit pulp, freshly prepared jams, and stored jams. Consumers preferred jams with a higher Total soluble solid/Titratable acid ratio, such as the num-num, stamvrug, and marula, with 64%, 70%, and 60% of the panelists indicating they would buy the jam. Jam color stability was greater when stored at 25°C than at 35°C. Num-num and stamvrug jams exhibited the best color retention, even after 6 months of storage at 25°C, with Delta E values of 1 and 4, respectively. Indigenous fruit jam processing, storage time, and temperature altered vitamin C, phenolic, flavonoid, tannin, and lycopene contents. Kei-apple 103 jams retained a high vitamin C content of 181.30 mg/100 g after 6 months of storage at 25°C. The Natal apricot demonstrated the highest lycopene content (39.23 mg/100 g) when stored at 35°C for six months and a substantial total carotene content of 23.37 mg/100 g, even under high-temperature conditions. Marula jam outperformed other indigenous fruit jams in retaining phenolics and flavonoids, with values of 3.47 mg GAE/g and 1.9 mg CE/g, respectively. Meanwhile, the tannin content of num-num and stamvrug jams stored at 35°C remained significant, measuring 6.17 mg and 6.67 mg cyanidin chloride/g, respectively. This study indicated considerable variation in physicochemical composition between Kei-apple selections. Future research on the effect of genetic variation of other indigenous fruits should also be included. Additionally, product development using Natal apricot and Kei-apple selections with extremely high acidity could focus on creating mixed fruit jams by incorporating other tropical fruits to enhance sensory appeal and achieve greater consumer acceptance. The indigenous fruit jams evaluated in this study demonstrate potential for development as niche products, offering opportunities to support income generation for small-scale processing enterprises.

Grass and woody species composition and diversity beneath mistletoe-infected and uninfected Sclerocarya birrea (marula) trees in two South African semi-arid savanna protected areas

BackgroundGlobalisation, urbanisation, and modernisation all influence traditional knowledge. More specifically, the introduction of exotic plants, historical policies, stigma attached to consuming wild edible plants (WEPs), changes in lifestyles, and environmental factors are reshaping peoples’ uses and knowledge of WEPs. This study assessed the relationship between ethnobotanical knowledge and consumption of WEPs in rural villages in the Polokwane and Aganang local municipalities, Limpopo Province, South Africa.MethodsThis study was conducted in four villages in the Limpopo Province, South Africa, between May 2018 and June 2019. Data about WEPs were collected using a household survey questionnaire administered to a total of 120 participants stratified by age and gender. Additionally, a free list of WEP species known by participants was collected as well as data on the traditional uses of each species.ResultsWe found that WEPs are generally well-known in the area, as participants listed an average of 17.7 ± 5.0 (8.4 ± 2.4 wild fruit species) and (9.3 ± 2.6 wild vegetable species). There was a significant difference between the number of species listed by age group, with the elderly listing a higher mean number of species (9.3 ± 2.6) compared to adults (8.1 ± 2.5) and the youth (7.8 ± 1.7). Vangueria infausta, Sclerocarya birrea subsp. caffra, Ximenia caffra, Amaranthus retroflexus, Citrullus lanatus, and Cleome gynandra were among the most listed species. There was a positive correlation between knowledge of WEPs and consumption rates. Most of the knowledge about WEPs was learnt from a family member (89%), own observation (86%), and a village elder (75%). This knowledge was mostly acquired from childhood through oral tradition (63%), through participation (21%), and consumption (12%).ConclusionsFuture preservation of WEPs knowledge could be encouraged by formalising indigenous knowledge in the education system and promoting WEPs in the media.