Jobs

Contact

Subscribe

NEWS

Study identifies banana varieties resistant to black Sigatoka and provides further insights into the disease pathogen
November 20, 2020
Black leaf Sigatoka, one of the most widespread and damaging banana diseases—causing yield losses of 20–50%—is widespread in Uganda and Tanzania, posing a challenge to banana production as bananas grown in East Africa are susceptible to the disease.   However, the good news is that five hybrids of East African Highland banana hybrids named NARITA, after their developers—the National Agricultural Research Organisation (NARO) of Uganda and IITA—are resistant to the deadly disease. 
Njeri explaining her research in the green house to a project partner during an annual meeting of the Breeding Better Banana project
Njeri explaining her research in the green house to a project partner during an annual meeting of the Breeding Better Banana project
These are among the key findings of a four-year comprehensive study on sustainable ways to control black leaf Sigatoka in Uganda and Tanzania conducted by Janet Njeri Kimunye as part of her PhD studies at Stellenbosch University carried out under the IITA project Improvement of banana for smallholder farmers in the Great Lakes region of Africa (Breeding Better Bananas) funded by the Bill & Melinda Gates Foundation.   Njeri was supervised by Prof. Altus Viljoen and George Mahuku from Stellenbosch and IITA, respectively. In October, Janet Njeri Kimunye successfully defended her thesis: “Distribution and genetic diversity of Pseudocerospora spp. associated with banana Sigatoka diseases in East Africa” and is set to graduate in December.  
Banana plants showing symptoms of black sigatoka
Banana plants showing symptoms of black sigatoka
Commercial farmers manage black Sigatoka disease by spraying fungicides weekly. However, this method is not suitable for smallholder farmers who represent most banana producers in Africa. Hence, finding banana varieties with resistance to black Sigatoka is the most effective solution for resource-poor farmers.   ”NARITA hybrids 2, 7, 8, 21, and 23, developed through conventional breeding, performed well across sites and had low disease pressure compared to susceptible local checks. These can be provided to farmers for managing black Sigatoka in the region,” said Kimunya.   “In addition, we identified the site Mitarula in Mbeya, Tanzania, as the most ideal and representative site for the disease evaluation and can save on resources by reducing multi-location disease evaluation,” she adds.  
Understanding the pathogen  
The basis for developing effective and sustainable disease management strategies is a sound understanding of the pathogen distribution, genetic diversity, and population dynamics. As part of the study, a survey was conducted in five banana-growing regions in Tanzania and Uganda to identify the Pseudocercospora spp. associated with Sigatoka leaf spots and determine disease severity.   Sigatoka-like symptoms were present in all localities and on all cultivars. Black Sigatoka caused by P. fijiensis was the most predominant species in all areas except Kilimanjaro, where Mycosphaerella musae was associated with Sigatoka-like leaf spots. Black Sigatoka was also found more severe in Uganda than in Tanzania.  
Banana plants showing symptomsof black sigatoka
Banana plants showing symptoms
of black sigatoka
Furthermore, P. fijiensis was detected at altitudes of up to 1877 m above sea level, suggesting an expansion in habitat range from the previous threshold of < 1350 m above sea level in East Africa. This expansion into new areas where the pathogen was previously not present is a major threat to the sustainability of banana production in the region.   Genetic diversity analysis revealed that P. fijiensis was reproducing both sexually and asexually. Such pathogens are difficult to manage, as they have a high potential to generate new and virulent strains that can easily overcome introduced resistance genes. Therefore, breeding programs have to broaden the sources of resistance to stay ahead of the game.   “As the most devastating pathogen, P. fijiensis is expanding its adaptation range to higher elevations, with evidence that previously resistant varieties are turning susceptible. It is important to identify new sources of resistance that can be incorporated into breeding programs and develop resistant varieties. We screened 95 banana cultivars and identified eight diploids with a similar reaction as the highly resistant Calcutta 4. These can be incorporated into breeding programs to broaden the genetic base of resistance to P. fijiensis, the cause of black Sigatoka,” Kimunya said.  Kimunya has also co-published two journal articles from this work:
  1. Kimunye, J.N., Muzhinji, N., Mostert, D., Viljoen, A., Bester-van der Merwe, A.E., and Mahuku, G. 2020. Genetic Diversity and Mating Type Distribution of Pseudocercospora fijiensis on Banana in Uganda and Tanzania. Phytopathology (
  2. Kimunye, J. N., Were, E., Mussa, F., Tazuba, A., Jomanga, K., Viljoen, A., Swennen, R., Muthoni, F. K., and Mahuku, G. 2019. Distribution of Pseudocercospora species causing Sigatoka leaf diseases of banana in Uganda and Tanzania. Plant Pathology DOI: 10.1111/ppa.13105 https://bsppjournals.onlinelibrary.wiley.com/doi/full/10.1111/ppa.13105

Contributed by

Recent stories

No items found

Leave a Reply

Your email address will not be published. Required fields are marked *

Scroll to Top
Olaosebikan, Olamide

Olamide Deborah Nwanze is a Senior Research Associate specializing in gender mainstreaming research to inform participatory and inclusive breeding, variety development, and seed systems policies regarding root, tuber, and banana (RTB) crops in the International Institute of Tropical Agriculture Headquarters, Ibadan, Nigeria. She is a PhD candidate at the University of Ibadan and holds an MSc and B. Agric in Agricultural Extension and Rural Development. Olamide is a fellow of the African Women in Agricultural Research and Development – Gender Responsive Agricultural Systems Policy (AWARD-GRASP) and the Gender Responsive Researchers Equipped for Agricultural Transformation (GREAT). She seeks to apply her gender-mainstreaming learnings, gender-responsive research, and policy development, and review expertise to facilitate women, youth, children, and vulnerable social group’s access to and adoption of agricultural Innovations that guarantee food, nutrition, income, and livelihood security in Africa. Her current roles include mentoring research fellows, development of guides and training manuals, implementation and adaptation of gender frameworks and tools, value chain actors’ engagement as citizen science partners, policy review and redesign, data management, and analysis. Her current research explores mixed methods and participatory and interdisciplinary approaches to capture and highlight gender dynamics, needs, preferences, and challenges stakeholders face within the agricultural livelihood value chain to prioritize gender-inclusive strategies in breeding programs, policy design, and implementation.

At IITA, she contributes to the implementation of the CGIAR Accelerated Breeding Initiative and Genetic Innovation Programs; participatory and gender research within the NextGen Cassava, HarvestPlus, RTBFoods, and Tricot-ClimMob 1000Farms Projects; and gender knowledge communication via the G-LENS webinar series, video documentary, policy briefs, publications, and blogs.

 

Recent publications

de Sousa, K., van Etten, J., Manners, R. Bello, A., Teeken, B., Olaosebikan, O., et al. 2024. The tricot approach: an agile framework for decentralized on-farm testing supported by citizen science. A retrospective. Agron. Sustain. Dev. 44, 8. https://doi.org/10.1007/s13593-023-00937-1

Madu, T., Onwuka, S., Nwafor, S., Onyemauwa, N., Ejechi, M., Ofoeze, M., Ukeje, B., Eluagu, C., Olaosebikan, O., Okoye, B., 2024. Gender-Inclusive Consumer Studies Improve Cassava Breeding in Nigeria in: Frontiers in Sociology, volume 9, number: 1224504, doi: 10.3389/fsoc.2024.1224504

Olaosebikan, O.; Bello, A.; Utoblo, O.; Okoye, B.; Olutegbe, N.; Garner, E.; Teeken, B.; Bryan, E.; Forsythe, L.; Cole, S.; Madu, T. 2023.  Stressors and Resilience within the Cassava Value Chain in Nigeria: Preferred Cassava Variety Traits and Response Strategies of Men and Women to Inform Breeding. Sustainability 15, 7837. https://doi.org/10.3390/su15107837

Okoye, B., Ofoeze, M., Ejechi, M., Onwuka, S., Nwafor, S., Onyemauwa, N., Ukeje, B., Eluagu, C., Obidiegwu, J.*, Olaosebikan, O., Madu, T.* 2023. Prioritizing preferred traits in the yam value chain in Nigeria: a gender situation analysis in: Frontiers in Sociology, volume 8, number: 1232626, pages 1 – 9, ISSN 2297-7775, 2023. https://www.frontiersin.org/articles/10.3389/fsoc.2023.1232626/full

Olaosebikan, O., Bello, A. A., de Sousa, K., Ndjouenkeu, R., Adesokan, M., Alamu, E. O., Agbona, A., van Etten, J., Kegah, F. N.*, Dufour, D., Bouniol, A., Teeken, B. 2023. Consumer acceptability of cassava gari-eba food products across cultural and environmental settings using the triadic comparison of technologies approach (tricot) in: Journal of the Science of Food and Agriculture,

Teeken, B., Olaosebikan, O., Bello, A. A., Madu, T.*, Cole, S. M. 2023. Qualitative assessment on the positionality and preferences of dyads in relation to cassava-related activities: working with tricot trial citizen scientists https://hdl.handle.net/10568/138326 Type: Manual

Bouniol, A., Ceballos, H., Bello, A. A., Teeken, B., Olaosebikan, O., Owoade, D., Agbona, A., Fotso Kuate, A., Madu, T.*, Okoye, B.*, Ofoeze, M.*, Nwafor, S.*, Onyemauwa, N.*, Adinsi, L.*, Forsythe, L., Dufour, D. 2023. Varietal impact on women’s labour, workload and related drudgery in processing root, tuber and banana crops: focus on cassava in sub-Saharan Africa in: Journal of the Science of Food and Agriculture, pages 1 – 25, ISSN 0022-5142,

Bello, A. A., Agbona, A., Olaosebikan, O., Edughaen, G., Dufour, D., Bouniol, A., Iluebbey, P., Ndjouenkeu, R.*, Rabbi, I. Y., Teeken, B. 2023. Genetic and environmental effects on processing productivity and food product yield: drudgery of women’s work in: Journal of the Science of Food and Agriculture, pages 1 – 32, ISSN 0022-5142, 5

Cavicchioli, M., Zimbiti, T., Teeken, B., Nwanze, D.O., Liani, M., Parkes, E. & Bello, A. 2023. IITA-Gender Responsive Breeding Training Report. Genetic Resources Center, IITA-HQ, Ibadan, 21-23 September, 2022. Ibadan, Nigeria: IITA, (34 p.).https://hdl.handle.net/10568/131368

Agbona, A. Peteti P., Teeken B., Olaosebikan O. Bello, A. A., Parkes, E., Rabbi, I. Y., Mueller, L., Egesi, C., Kulakow, P. 2022. Data Management in Multi-disciplinary African RTB Crop Breeding Programs. In: Williamson, H.F., Leonelli, S. (eds) Towards Responsible Plant Data Linkage: Data Challenges for Agricultural Research and Development. Springer, Cham. https://doi.org/10.1007/978-3-031-13276-6_5

Lora Forsythe, Pricilla Marimo, Sarah Mayanja, Olamide D. Olaosebikan, Esme Stuart, Bela Teeken, Benjamin Okoye, Tessy Madu, (2021). Cross-product Gender Analysis of RTBfoods Step 2 Gendered Food Mapping on RTB Products. Understanding the Drivers of Trait Preferences and the Development of Multi-user RTB Product Profiles, WP1. London, UK: RTBfoods Field Scientific Report, 30 p.

Teeken, B., Garner, E., Agbona, A., Balogun, I., Olaosebikan, O., Bello, A., Madu, T., Okoye, B., Egesi, C., Kulakow, P. and Tufan, H.A. 2021. Beyond “Women’s Traits”: Exploring How Gender, Social Difference, and Household Characteristics Influence Trait Preferences. Frontiers Sustainable Food Systems 5:740926. https://doi.org/10.3389/fsufs.2021.740926

Teeken, B., Agbona, A., Bello, A., Olaosebikan, O., Alamu, E., Adesokan, M., Awoyale, W., Madu, T., Okoye, B., Chijioke, U., Owoade, D., Okoro, M., Bouniol, A., Dufour, D., Hershey, C., Rabbi, I., Maziya‐Dixon, B., Egesi, C., Tufan, H. and Kulakow, P. (020. Understanding cassava varietal preferences through pairwise ranking of gari‐eba and fufu prepared by local farmer–processors. Int J Food Sci Technol. https://doi.org/10.1111/ijfs.14862

Bela Teeken, Olamide Olaosebikan, Ireti Balogun, Benjamin Okoye, Tessy Madu, Steven Cole, Abolore Bello, Elizabeth Parkes. (2020). Piloting the G+ customer and product profile tools for gender-responsive cassava breeding in Nigeria. Nigeria: International Institute of Tropical Agriculture (IITA). https://hdl.handle.net/20.500.11766/13000