UMP Scholarship Collection:

Assessment of the performance of Maize (Zea mays L) intercropped with Jack bean (Carnavalia ensiformis) under subtropical conditions.

Wed, 01 Jan 2025 00:00:00 GMT

Title: Assessment of the performance of Maize (Zea mays L) intercropped with Jack bean (Carnavalia ensiformis) under subtropical conditions. Authors: Tumber, Veronica Nomcebo. Abstract: Food demand in Sub-Saharan Africa continues to rise, while soil fertility declines, climatic conditions remain uncertain, and farming systems rely heavily on chemicals. Sustainable cropping practices such as cereal legume intercropping are needed to address these challenges. This study therefore evaluated productivity of maize (Zea mays L) intercropped with jack bean (Canavalia ensiformis) under subtropical conditions of Mpumalanga Province, South Africa, to determine whether intercropping maize with jack could improve soil fertility and increase yield of maize. A randomized complete block design was used with sole maize, sole jack bean, and intercrop treatments. Growth and yield traits of both crops were measured, and soil samples were taken before planting and after planting. Seed quality were determined for protein, fat, fiber, and carbohydrate contents. One-way ANOVA and correlation analysis were used for comparisons. Intercropping markedly produced different outcomes across every growth and yield metric when compared with sole maize (p < 0.001). Specifically, intercropped maize demonstrated greater performance in various metrics, including protein content, chlorophyll content, plant height, stomatal conductance, leaf index, moisture content, and stem diameter. Intercropped maize had protein contents of 10.88% in season 1 and 8.12% in season 2, compared with 9.61% and 7.87% for sole maize in the same season. Furthermore, the intercropped treatment produced a land equivalent ratio (LER) exceeding 1, highlighting its efficiency in land use compared to monocropping. Intercropped maize averaged higher values across all yield components. Furthermore, cob length was 28.09 cm, kernel count averaged at 546.7 per cob, 100-seed weight was 0.5164 kg, and total seed weight amounted to 4.435 kg per block. Although yields declined in Season 2 due to drier conditions, intercropped maize still maintained an advantage with longer cobs (25.34 cm), more kernels (471.1 per cob), and higher seed weight (0.795 kg per block). Additionally, root nitrogen concentration was greater in intercropped maize than in sole maize during both seasons, intercropped roots averaged at 0.53% N versus 0.46% in sole maize in season 1, and 0.43% versus 0.40% in season 2. Additionally, intercropping maize with jack bean has significantly enhanced soil mineral nutrients, resulting in an average increase of 30kg N/ha in nitrogen, a 25% increase in phosphorus content and improved potassium stability. In addition, jack beans are underutilized, with no commercial varieties available and limited awareness among farmers. Research should focus on breeding adapted varieties, promoting its use in food and feed, and assessing its potential for poverty reduction. Description: Dissertation (Masters(Science))-- University of Mpumalanga, 2025

Encephalartos ghellinckii-microbe symbiosis, soil nutrient inputs and enzyme activities in KwaZulu-Natal and Eastern Cape grasslands.

Thu, 01 Jan 2026 00:00:00 GMT

Title: Encephalartos ghellinckii-microbe symbiosis, soil nutrient inputs and enzyme activities in KwaZulu-Natal and Eastern Cape grasslands. Authors: Tshwane, Mongwadi. Abstract: Cycads are an ancient group of gymnosperms, with over 300 species classified into three families and 10 genera. Originating around 300 million years ago, they are now primarily found in tropical and subtropical regions, where they play crucial ecological roles in carbon sequestration, nutrient cycling, and soil stabilization. A key adaptation of cycads is their symbiotic relationship with nitrogen (N)-fixing bacteria in their coralloid roots, which convert atmospheric N into forms such as ammonia that the plants can assimilate for growth. This trait, which predates its occurrence in legumes and enables cycads to thrive in nutrient-deficient soils, such as those in grassland ecosystems. However, most studies on the role of plant symbiotic relationship with N-fixing bacteria have focused on angiosperms, with little knowledge on their relationship with cycads. Also, over 70% of the cycad species are threatened with extinction, and their loss would have significant ecological consequences due to their vital ecosystem services. This study aims to investigate the symbiotic interactions between Encephalartos ghellinckii and N-fixing bacteria, the role of soil microbial communities and enzyme activities, in regulating soil nutrient availability and influencing the plant’s N source reliance. By examining these factors, this research seeks to understand the contribution of the microbes to the survival of E. ghellinckii in nutrient-deficient, acidic grasslands. To achieve this, microbial diversity in the coralloid roots, rhizosphere, and non-rhizosphere soils of E. ghellinckii was assessed across four sites (Cathedral Peak, Thabankulu, Oribi Gorge, and Umgano). The study also examined extracellular enzyme activities associated with these microbes and their contribution to soil nutrient availability. Additionally, soil nutritional status, including pH, nutrient concentrations, total cations, and exchange acidity, was analyzed to determine its influence on cycad-microbe symbiosis. The N source preference of E. ghellinckii was calculated from atmospheric derived N and plant N concentration. Bacterial strains identified in E. ghellinckii coralloid roots, rhizosphere, and non-rhizosphere soils included Bacillus, Rhizobium, Paraburkholderia, Enterobacter, Caballeronia, Klebsiella, Pseudomonas, Inquilinus, and Arthrobacter. These microbes contributed to N fixation, N cycling, and phosphate solubilization. No significant differences were observed in phosphorus-cycling (acid and alkaline phosphatase), nitrogen-cycling (nitrate reductase), and carbon-cycling (β glucosidase) enzyme activities between rhizosphere and non-rhizosphere soils. Increased enzyme activity was associated with increased nutrient availability and responses to nutrient limitations, highlighting the complex interactions governing soil nutrient dynamics. Isotope δ15N analysis revealed that E. ghellinckii derived more than 80% of its N from atmospheric fixation, while less than 20% was soil-derived. A positive correlation was observed between soil phosphorus (P) concentrations and the proportion of N fixed from the atmosphere across all sites. These findings highlight the role of microbial symbiosis and associated enzyme activities in enhancing nutrient availability in acidic, nutrient-poor grassland soils. Furthermore, this association facilitates E. ghellinckii’s ability to access and utilize atmospheric N, supporting its persistence in nutrient deficient ecosystems. Description: Dissertation (Masters(Science))--University of Mpumalanga, 2026

Indigenous knowledge on the uses and factors that determine the use of strychnos spinosa lam found in Bushbuckridge, Mpumalanga, South Africa.

Thu, 01 Jan 2026 00:00:00 GMT

Title: Indigenous knowledge on the uses and factors that determine the use of strychnos spinosa lam found in Bushbuckridge, Mpumalanga, South Africa. Authors: Thothela, Sanele Nomfundo Sandisiwe. Abstract: In sub-Saharan Africa, Indigenous knowledge (IK) is a vital source of information about the local environment, including the identification and use of various plant species. One of the plant species that has attracted much attention in the area is Strychnos spinosa Lam. (S. spinosa), commonly known in English as ‘spiny monkey orange’ or ‘umKwakwa’ in isiZulu and isiXhosa, and used by local communities for medicinal, nutritional, and cultural purposes. The aim of this study was to document the ethnobotanical uses of Strychnos spinosa among selected communities in Bushbuckridge, Mpumalanga Province, South Africa, and to identify the taxonomic identity of market-sold Strychnos products using DNA barcoding. This study investigates the ethnobotanical uses and taxonomic authenticity of S. spinosa in Bushbuckridge, Mpumalanga Province, South Africa. An ethnobotanical survey was conducted through in-depth interviews with 108 participants selected using purposive and snowball sampling techniques across six settlements in Bushbuckridge Local Municipality, Mpumalanga Province, South Africa. The sites were selected based on their high reliance on indigenous plant resources and the presence of active informal medicinal plant markets, while participants were selected for their knowledge and experience in use of S. spinosa. Through qualitative and quantitative analyses, the research revealed the diverse uses of the plant, including its nutritional, medicinal and cultural significance. The plant’s average Use Value (UV) and Relative Frequency of Citation (RFC) were determined and found to be 1.9 and 0.4, respectively. The findings revealed that 93% of participants depended on wild harvesting, while concerns about its declining availability due to urbanisation, agriculture and climate change were commonly reported. Market participation was high, with 99% of respondents selling S. spinosa products. However, conservation efforts were deemed inadequate, with 46% of participants pointing out lack of formal protective measures. DNA barcoding was used to verify the authenticity of fruit, seed and powdered samples of Strychnos spp. sourced from Bushbuckridge Local Municipality, Mpumalanga Province, South Africa. DNA extraction and amplification were performed using two plastid markers, rbcLa and matK, followed by Sanger sequencing. Sequences obtained were aligned and analysed using BLAST against GenBank. DNA barcoding results revealed that none of the analysed market samples matched S. spinosa. Instead, samples showed a high degree of sequence identity (≥99% similarity) with other Strychnos species, v particularly S. madagascariensis, S. innocua, and S. xanthoclada. Results confirm species identity through DNA barcoding analysis and suggest possible misidentification or substitution within local markets, despite the ethnobotanical focus on S. spinosa. The results confirm that molecular identification is feasible even for degraded and processed material. The phylogenetic placement of all Bushbuckridge Local Municipality samples within a well-supported S. madagascariensis clade further validated BLAST identifications and showed no evidence of adulteration or substitution. Collectively, the study underscores the importance of integrating Indigenous Knowledge with molecular techniques to enhance the safety of medicinal plants, conserve biodiversity, and inform evidence-based policies and regulations aligned with the Nagoya Protocol and South African biodiversity frameworks. This work provides novel molecular data on southern African Strychnos, supports pharmacovigilance in traditional medicine markets. This study also provides evidence- based insights into the mismatch between ethnobotanical knowledge and molecular identification, revealing that market-sold products may not correspond to S. spinosa. This highlights potential misidentification or substitution within local medicinal plant markets and underscores the critical role of DNA barcoding in ensuring species authenticity and protecting indigenous knowledge systems. Description: Dissertation (Masters(Science))-- University of Mpumalanga, 2026

Re-evaluating vegetation community dynamics and well-being of the lower uThukela and uMvoti rivers in KwaZulu-Natal, South Africa.

Wed, 01 Jan 2025 00:00:00 GMT

Title: Re-evaluating vegetation community dynamics and well-being of the lower uThukela and uMvoti rivers in KwaZulu-Natal, South Africa. Authors: Thobela, Daphney. Abstract: Aquatic ecosystems are deteriorating due to the numerous anthropogenic stressors affecting them. Riparian vegetation and macrophytes can all be established as ecological indicators of the well-being of rivers and contribute to the sustainable management of water resources. In this study riparian vegetation and macrophyte communities were assessed to determine their condition and structures at the lower uThukela and uMvoti Rivers using historical data from 2013 and data collected from the same study sites in 2023.To determine the ecological state of the macrophytes and riparian vegetation communities, data was collected to represent the vegetation communities of the riparian ecosystem and macrophytes ecosystem using phytosociological methods. For this study, cross-sections for the sampled rivers, river discharge data (m³/s ), water quality variables, substrate types, water levels (m) and vegetation communities data were determined. The plant community data was superimposed into cross-sections of the rivers and used to provide information pertaining to the relative elevation and hydraulic niche requirements of each individual plant species. Substrate at each site associated with plant communities were estimated and categorized into either silt, mud, sand, gravel, cobble, boulders and bedrock following the grain-size analysis and sieving technique. The biological community structures and their associated abiotic variables were assessed using multivariate statistical techniques in the form of Canonical Correspondence Analysis (CCA) and Redundancy Analysis (RDA) multivariate approaches to determine the well-being of uThukela and uMvoti Rivers across the sampled sites. The significant threshold selected for this study was restricted to p = 0.05 where p< 0.05 is significant and p> 0.05 is regarded as not significant. Change detection results indicated a decline in both the macrophytes (4914 Ha to 4002 Ha) and riparian vegetation (23292 Ha to 19055 Ha) communities of the uThukela River in the 10-year period (2013-2023).Most of the plant communities were categorized under sub-adult and adult age groups except for few juveniles. The multivariate analysis indicated that water quality is a significant driver to the observed vegetation communities of the lower uThukela River. Macrophytes and riparian vegetation communities data from the sampled sites of the lower uMvoti River were also evaluated using similar multivariate analysis methods. Change detection method indicated an increase in the riparian vegetation communities and a decrease in macrophytes communities. The riparian vegetation communities of uMvoti River increased from 8620 Ha to 10952 Ha between 2013 and 2023, respectively. A decline in macrophytes communities was observed in the period between 2013 and 2023 with 4488 Ha and 2106 Ha, respectively. Most of the sampled plant communities in the lower uMvoti River were observed as adults. The population structure of the river’s vegetation communities is concerning as it is lacking juvenile individuals. The multivariate analysis indicated that water quality and substrates are not significant drivers of the observed plant communities in the lower uMvoti River. The plant communities superimposed to the cross sections for both uMvoti and uThukela Rivers did not show any clear association with elevation and water requirements. Description: Dissertation (Masters(Science))-- University of Mpumalanga, 2025