Banana Bunchy Top Disease in Rwanda: Identifying Disease Presence and Potential Areas at Risk.

Abstract

Banana Bunchy Top Disease (BBTD) has been reported in southwestern Rwanda since the 1980s. Recent sporadic observations of BBTD in western and central regions, made by extension services and the Rwanda Agriculture and Animal Resources Development Board (RAB), merited a comprehensive field survey across the country. This survey was performed in 2022-2023 to confirm and map the presence of BBTD in suspected areas in Rwanda. Combining the Rwandan survey with BBTD surveys in neighboring countries (eastern DR Congo, Burundi and Uganda), a BBTD probability model was developed for Rwanda, taking into account environmental, land-use/land-cover and socio-economic variables, from which a country-wide vulnerability map was compiled. Field surveys confirmed that BBTD has spread to the Nyamasheke and Rubavu district along lake Kivu, to all districts of Kigali and the bordering districts Rulindo and Kamonyi. Predictive risk mapping confirms that these regions are the highest risk areas of the country. South-eastern regions were identified as additional areas at risk for BBTD. While BBTD is currently not widespread across Rwandan banana production zones, key recommendations are made to prevent further incursions. Specifically, Kigali was identified as a new hotspot for BBTD spread in Rwanda, and here coordinated and rigorous eradication is key. Farmers' interviews revealed a critical need for awareness campaigns and training on BBTD. Most farmers were unaware of how the disease spreads, effective disease recognition, how to prevent its introduction and establishment, and how to manage the disease at both initial and advanced stages, making a comprehensive management approach imperative.