Natural Sciences
Banana’s Large Plant Body Size an Advantage to Disease Control – Mak Scientists
Unlike for plants, in animals especially humans, body mass index (BMI, which is a person’s weight divided by the square of height) is a measure of physical health and pre-disposure to conditions like obesity. BMI does not make sense in plant health because of differences between plant and animal physiological systems.
However, large body size in plants may have some advantages. Apart from controlling a larger proportion of available resources and space within crowded vegetation, what other advantage does a large plant body size offer to an individual plant?
The banana’s plant body architecture
From the botanical point-of-view, the banana plant is a gigantic herb. A plant that is a herb or “herbaceous” is unable to undergo “secondary growth” and cannot form wood during its vegetative development.
The banana plant springs from an underground “true stem”, also called the “corm” or “rhizome”, to form a false stem, also called a “pseudostem” of 2-7 m height. The pseudostem is composed of the basal portions of leaf sheaths and is crowned with a rosette of 10 to 20 oblong to elliptic leaves that sometimes attain a length of 2-4 m and a breadth of 70 cm.
In mature banana plants, true stem emerges at the top of the pseudostem and bends downward to become a bunch of 10 to 300 individual fruits, or fingers, grouped in clusters, or hands, of 3 to 22. The edible part of the bunch is the female. In contrast, the inedible distal part, including the purple-colored cone-shaped end (locally known in some Ugandan dialects as “omukanaana” or “empumumpu”) constitutes the male part of the bunch.
How is the giant banana size an advantage in disease control?
A new study, titled “Xanthomonas campestris pv. musacearum Bacterial Infection Induces Organ-Specific Callose and Hydrogen Peroxide Production in Banana” and led by a team of scientists at the Department of Plant Sciences, Microbiology and Biotechnology at Makerere University in collaboration with the University of California, Davis, USA, shows how the giant banana body size can be used to control banana Xanthomonas wilt (BXW) disease.
According to Prof. Arthur Tugume, the lead scientist of this study and expert in plant pathology, when plants get infected, they respond instantly by implementing different strategies that limit the multiplication and/or mobility of the disease agents (pathogens). “For example, plants rapidly produce reactive oxygen species (ROS) such as hydrogen peroxide, superoxide ions, and hydroxyl ions. These ROS act as rapid messengers in the plant tissues to activate additional responses spreading over the entire plant body. This helps the plant’s distant tissues or organs to be aware and prepare advance defenses against the intruding pathogens”.
Prof. Dinesh-Kumar the project’s research collaborator based at the University of California-Davis, USA and expert in plant biology explains that “disease is a form of stress in plants and plants cannot perform well their biological functions when they are sick since they have to spend a lot of energy fighting against the disease. This is why disease control is important to enable plants grow well and yield high.”
The research indicates that ROS set in motion additional processes to ensure limited impact of disease and pathogens on the plant. For example, Hydrogen peroxide (H2O2), which is a ROS, has direct bactericidal, fungicidal or other anti-effects on the pathogens. Also, following H2O2 production, a unique plant carbohydrate, named “callose” starts to accumulate in large quantities within plant cells as a means of fortifying plant tissues. Callose differs from the other usual plant carbohydrates such as starch or cellulose because of the way its structures are formed.
Increased production of callose acts as a roadblock to any pathogen e.g., bacteria by limiting bacterial movement that would otherwise allow ease of attack on other tissues or cells at distant locations in the plant. “Although these plant defense responses are rapid, plant organs that are distant from the site of pathogen attack can be instrumental and block progression of bacteria or other pathogens by depositing callose in advance at strategic points” Prof. Tugume explains.
However, Prof. Tugume notes that callose participates also in many other normal developmental processes of plants, and for that reason, there is always some “housekeeping” callose in the plant tissues even without pathogenic infection. “This means that one must be able to accurately and quantitatively distinguish between ‘stress-induced’ and normal ‘housekeeping’ callose”, he adds.
How was the study done?
In this study, the researchers used young (2.5-months old) banana plantlets that had been generated from tissue culture at Kawanda Agricultural Research Institute. They then infected the plantlets with a bacterium called Xanthomonas campestris pv. musacearum (Xcm). This bacterium is the causative agent of banana Xanthomonas Wilt (BXW), the most destructive disease of bananas in East and Central Africa (ECA).
The banana leaves, pseudostems, corms and roots were analyzed for callose and compared with the control plants that had been inoculated with water instead of bacteria. H2O2 production was monitored by “DAB staining”, and by “spectrophotometry” while the analysis of callose was done by two methods: staining and visualization of callose using florescence microscopy, and using “Sandwich Enzyme-Linked Immunosorbent Assay” methods.
What did the researchers discover and how can it be used in BXW disease control?
This study revealed that the underground corm tissues assemble the stiffest resistance against BXW by depositing the highest concentrations of callose, while the pseudostem produced the highest quantities of H2O2. This is interesting for three (3) main reasons:
- Firstly, Xcm bacteria often enter through the leaves in regular plantation husbandry; hence, the corm being distant from leaves gives it an anatomical advantage in promoting the ability of lateral plants to escape Xcm infection.
- Secondly, the corm is an organ of perennation supporting vegetative and perennial continuity of the crop across seasons; hence it is charged in ensuring a disease-free next generation by severely constraining “mother-child transmission” of Xcm bacteria.
- Thirdly, the control of BXW now becomes easy when farmers are observant to the first aerial disease symptoms because Xcm is strongly constrained by bottlenecks in the pseudostem and corm.
Therefore, at the onset of aerial symptoms, diseased peudostems should immediately be removed by aseptically cutting them off at the corm without interfering with symptomless lateral shoots, which allows continuous food production and disease control to go on simultaneously. This is facilitated by the large size of the banana plant because at the onset of leaf symptoms (2.5 to 5 meters away from the corm), the bacteria have not yet arrived at the base of the pseudostem where the diseased plant can be cut off from the corm. This gives chance to a farmer to eliminate the infected pseudostems early (in 1 to 7 days) since the appearance of leaf symptoms.
This research was part of the PhD studies for Mr. Abubakar S. Mustafa at Makerere University and University of California, Davis. According to Mr. Mustafa, these discoveries make the management of BXW in banana plantations easy as long as the farmers are observant and act fast by removing diseased plants aseptically.
This study has been published by the American Phytopathological Society (APS) in an open access journal, “PhytoFrontiers”, and is freely accessible on https://apsjournals.apsnet.org/doi/full/10.1094/PHYTOFR-11-21-0073-R.
This study was funded by the Bill and Melinda Gates Foundation through the National Agricultural Research Organization (NARO), Uganda. The project had partners including the International Institute of Tropical Agriculture (IITA), the Alliance for Bioversity International and International Centre for Tropical Agriculture (CIAT) and Centre for Agriculture and Bioscience International (CABI).
For more details, contact;
Prof. Arthur Tugume
Lead Scientist
College of Natural Sciences (CoNAS)
Makerere University
Email: arthur.tugume@mak.ac.ug
Tel: +256772514841
Mr. Abubakar S. Mustafa
Co-Author and PhD student on the study
Email: mustafa.abubakar.sadik@gmail.com
Tel: +256702813233
Hasifa Kabejja
Principal Communication Officer
College of Natural Sciences (CoNAS)
Makerere University
Email: pr.cns@mak.ac.ug
Tel: +256774904211
A team of researchers from Makerere University has presented findings of a study on the persistent poor performance in Biology in national examinations to senior officials at the Ministry of Education and Sports.
The findings were shared during a dissemination meeting attended by the Ministry’s top management, led by Permanent Secretary Kedrace Turyagenda.
The study, commissioned by the Ministry in 2023, was conducted by researchers from the College of Natural Sciences (CoNAS) and the College of Education and External Studies (CEES). It was spearheaded by Prof. Fredrick Muyodi as Principal Investigator, alongside Assoc. Prof. Josephine Esaete (Co-Principal Investigator) and Prof. Arthur Tugume among others.
Titled “Examining the Factors Accounting for Poor Academic Performance in Biology in Uganda’s National Examinations,” the study covered all regions of the country, engaging more than 5,200 respondents across 100 districts through surveys, interviews, and observations.
Key findings
The research identified limited field-based learning and poor digital access as the most critical and consistent challenges affecting both Ordinary and Advanced Level students across all regions.
At Advanced Level, the lack of project-based learning was also cited as a significant constraint. Learners reported limited engagement with Biology beyond the classroom, a factor that weakens conceptual understanding and application in examinations.
The study further highlighted the role of community attitudes and perceptions in shaping student performance in the subject.
Recommendations
The researchers recommended increased investment in field-based learning, including field trips and project work, as well as expansion of digital infrastructure to improve access to learning resources.
Other proposed measures include strengthening school laboratory facilities, enhancing teacher capacity through continuous professional development, promoting student engagement through academic clubs and mentorship programmes, and fostering stronger family and community support for science education.
Next steps
The research team is seeking funding to pilot targeted interventions, particularly in regions most affected by the challenges identified, and to develop a monitoring and evaluation framework to guide implementation.
The findings are expected to inform policy and interventions aimed at improving Biology performance and strengthening science education in Uganda.
By Dr. Alice Nabatanzi
At the Department of Plant Sciences, Microbiology, and Biotechnology (PMB) in the College of Natural Sciences, we are moving beyond the classroom to bring science to life. We are proud to showcase our innovative work with the Biotechnology Class of 2026. Our Product Development Centre has transitioned from theoretical research to practical, market-ready innovations. By applying advanced scientific principles, our students are developing tangible solutions that address everyday needs in nutrition, health, and industry.
Below are the latest products developed by our talented innovators:
- Nutrition & Food Technology: Vitamin A-rich bread, banana vinegar, food syrups, and fortified bio-snacks.
- Clinical Hygiene: Perfumes, Deodorants, Antibacterial gels, herbal toothpaste, shaving cream, and herbal mouthwash.
- Natural Wellness: Natural formulas for gut health, pain relief, cough lozenges, and nasal decongestants.
- Advanced Cosmeceuticals: Turmeric SunGuard patches, skin serums, toners, and anti-dandruff shampoo.
- Home & Industrial Solutions: Shoe deodorizing sprays, surface cleaners, and scented hygiene products.
- Agri-Tech: Natural bioindicator kits designed to monitor and improve soil health.
Through these initiatives, PMB continues to lead the way in re-engineering science for the benefit of our community and the world.
Meet the Biotechnology Class of 2026. While everyone else is still stuck in textbooks writing about “how things might work,” we’re in the lab making sure they actually do. We’ve officially moved past the days of just talking about science and stepped into the era of real-world industry. From our Product Development Centre to the global market, we are setting a new standard for Biotechnology at CoNAS. We aren’t just graduating with degrees; we’re graduating with the future in our hands.
What’s Next: We’re Just Getting Started
This is only the beginning. We’re already working on the next wave of products, from eco-friendly bio-packaging and better probiotics to smart-crop tech that will change how we eat, heal, and live. We aren’t just waiting for the future to happen we’re in the lab building it right now.
Dr. Alice Nabatanzi is a Senior Lecturer of Phytomedicine and Nutraceuticals at the College of Natural Sciences (CoNAS), Makerere University
Natural Sciences
Transforming Food Waste into Clean Energy: Makerere University Researchers Equip Mbarara City Residents with Biogas Production Skills
*****Led by Dr. Patience Tugume from the Department of Plant Sciences, Microbiology and Biotechnology at Makerere University, a project titled “Bio-innovation of biogas, biofertilizer, and biopesticide through the utilization of bio-waste” is promoting the transformation of household food waste into biogas and other valuable bio-products. The project team disseminated the research findings to stakeholders in Mbarara City on 15th April 2026.
About the Project
A one-year bio-innovation initiative focused on converting household food waste into biogas, biofertilizer, and biopesticides has yielded promising results in improving access to clean energy and promoting sustainable agricultural practices in peri-urban communities of Mbarara City.
The project, implemented by Makerere University in collaboration with Frevasema Ltd in Mbarara, was supported by UNESCO and the International Development Research Centre (IDRC) – Canada through the Organization for Women in Science for the Developing World (OWSD). Launched in January 2024, it is led by Dr. Patience Tugume from the Department of Plant Sciences, Microbiology and Biotechnology at Makerere University.
The initiative has been implemented across five divisions of Mbarara City – Kakoba, Kamukuzi, Nyamitanga, Biharwe, and Nyakayojo – with additional field trials conducted in Masha Sub-county, Isingiro District.
Objectives of the project
The central aim of the project was to demonstrate how biodegradable household waste can be transformed into useful products, particularly biogas for cooking, as well as organic biofertilizers and biopesticides for improved crop production.
Key objectives of the project included: establishing a spin-off centre of bioreactors at the business partner institution (Frevasema Ltd) to demonstrate sustainable production of biogas, biopesticides and bio-fertilizers; training and equipping women and youth with hands-on skills in biogas production and usage; evaluation of yields from different bio wastes; and creation of linkages between academia, the private partner and rural communities in up-scaling production of biogas, biopesticides and bio-fertilizer from household/urban biodegradable wastes.
Key Activities and Dissemination of Project Findings
The project team conducted a survey to assess community perceptions and the factors influencing the adoption of biogas as an alternative cooking energy source in peri-urban areas of Mbarara City. In addition, biodigester tanks were constructed at FREVASEMA Ltd to support training and knowledge transfer activities.
Field experiments were undertaken in Masha Sub-county, Isingiro District to evaluate the effectiveness of an integrated biofertilizer–biopesticide. Further experiments to assess biogas yield from different types of food waste were conducted at Makerere University.
The team also developed an integrated biofertilizer–biopesticide by enhancing bioslurry, a by-product of biogas production, with plant extracts known for their pesticidal properties. The effectiveness of this product was tested on the growth performance of green pepper, cabbage, and eggplant.
In line with one of the project objectives, the team also conducted hands-on training in biogas production from food waste for 35 students and 6 staff members of MAMITA Technical and Business Institute.
Dissemination workshop
On 15th April 2026, the project team led by Dr. Tugume held a dissemination workshop to share findings with stakeholders and discuss strategies for scaling up the outcomes.
Findings from the research highlight the strong potential of biogas in contributing to sustainable energy solutions, improving livelihoods, and enhancing environmental conservation through proper food waste management.
Key research findings
- The application of integrated biofertilizer–biopesticide presents a viable alternative to scarce, expensive, and environmentally harmful inorganic fertilizers for enhancing vegetable productivity.
- The study revealed that approximately 90.7% of respondents depend on charcoal and firewood as their primary cooking fuel.
- While 92.1% of respondents were aware that biogas is produced from animal and plant materials, only 7.9% recognized that food waste can also serve as a feedstock, indicating limited awareness of its full potential.
- Banana and potato peels, as well as posho and potatoes leftovers, and green vegetable trimmings, were identified as the most commonly generated food wastes.
- A majority of respondents strongly agreed that biogas is a cleaner and more sustainable energy alternative compared to firewood.
- Key barriers to biogas adoption included inadequate technical knowledge, safety concerns regarding biogas systems, and the high costs of constructing and maintaining biodigesters.
- The extremely low adoption rate of biogas technology (0.3%) indicates significant underutilization despite its potential to mitigate fuel shortages.
- There is a prevailing perception that biogas is suitable for cooking and can effectively replace biomass fuels, given the availability of sufficient feedstock from household food waste, human waste, and animal manure.
- Potato and posho residues were identified as the most suitable primary feedstocks for biogas production due to their high nitrogen content, volatile solids, and total organic carbon (TOC).
- Effective collection and proper segregation of food waste are essential for ensuring a consistent and uncontaminated supply of feedstock for biogas production systems.
- Further research is recommended on integrated biogas systems that combine anaerobic digestion with other renewable energy technologies, such as solar energy or bioelectrochemical systems, to improve overall energy recovery efficiency.
- Vegetables treated with the integrated biofertilizer–biopesticide consistently exhibited superior performance across all growth parameters compared to those treated with inorganic fertilizers (including 5% cypermethrin pesticide) and untreated controls.
Stakeholder engagement and appreciation of the initiative
During the dissemination workshop, Dr. Patience Tugume, the Principal Investigator, expressed gratitude to UNESCO and the International Development Research Centre (IDRC)-Canada, through the Organization for Women in Science for the Developing World (OWSD), for funding the project. She appreciated the research team composed of Dr. Asiimwe Savina, Prof. Maud Kamatensi-Mugisha, Prof. Bazirake Byarugaba, Ms. Catherine Kiconco and Mr. Muhumuza Robert for their contribution. She equally appreciated all participants for contributing valuable information to the study.
Stakeholders commended the project for its relevance and community impact.
Prof. Bunny Lejju Julius from Mbarara University of Science and Technology, appreciated the project team for developing an innovation that directly addresses community needs and aligns with the principles of the competency-based curriculum, particularly the translation of academic knowledge into practical application. He advised that sustainability of the initiative could be strengthened through a multiplier approach, where the trained learners cascade the knowledge to other community members. He further recommended the identification of institutional staff who can undergo training at the spin-off centre and subsequently serve as trainers within their respective communities.
The portable biodigester system was recognized as a simple, affordable, and practical technology with the potential to provide a cost-effective alternative to charcoal and electricity. Participants noted that while resistance to change remains a challenge, continuous awareness creation is essential to promote adoption and facilitate behavioral change.
Mbarara District Forest Officer, Ms. Ainembazi Joses, highlighted the importance of the biogas production project in environmental conservation. She noted that the initiative contributes to reducing deforestation by offering an alternative to firewood and charcoal, thereby supporting sustainable natural resource management.
The Local Council Chairperson of Mailo-Biharwe Division, Mr. Didas Katabazi, appreciated the project team for the innovative work and its potential benefits to the community. He pledged to use his office to advocate for increased government support to scale up the project.
The Resident City Commissioner of Mbarara City expressed concern over the rising levels of deforestation in the district and commended the Principal Investigator for spearheading the innovation. He reaffirmed the government’s commitment to supporting science and innovation. He emphasized the importance of integrating environmental protection with agricultural productivity, explaining that food security remains a national priority. He further noted that the project demonstrates the concept of waste valorization, where organic waste is transformed into valuable products such as biofertilizers and biopesticides, thereby enhancing agricultural productivity. He pledged to engage the Office of the President to support wider dissemination of the project outcomes. Additionally, he encouraged the trained students to act as ambassadors of the project by sensitizing communities on the benefits of biogas as an alternative source of cooking energy.
Way forward
- The government should invest in constructing bio digesters for households at subsidized prices or offer them financial assistance to cater for bio digester construction.
- Awareness campaigns about the production and use of biogas and associated benefits should be intensified in communities to dispel the negative perceptions.
- Provision of technical training in operating and maintenance of biogas installations should be conducted.
- Sorting of wastes at household level should be emphasised to separate biodegradable from non biodegradable ones.
- The integrated bio-fertilizer-bio-pesticide is an effective, sustainable strategy to increase vegetable productivity while improving soil health in nutrient-limited soils.
- The project recommends adoption of bio-fertilizers (e.g., bio-slurry) which are affordable and can be made from kitchen and market waste to reduce dependence on expensive chemical fertilizers to improve crop growth while controlling pests safely in addition to being safe for humans and the environment.
Donation of portable biodigester systems
As part of the commitment to translate research into tangible benefits, the project awarded two women and MAMITA Technical and Business Institute with portable biodigester systems for installation and use in their households and institution respectively. These systems will serve as demonstration units within the community showcasing the practicality, affordability, and impact of clean energy solutions at the household level.
Report compiled by Dr Patience Tugume, Principal Investigator & Senior Academic Staff in the Department of Plant Sciences, Microbiology & Biotechnology at Makerere University
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