Banana bunchy top disease (BBTD), caused by the banana bunchy top virus (BBTV), poses a significant threat to banana production in sub-Saharan Africa. The disease, first reported in the Democratic Republic of Congo (DRC) in the 1960s, has now spread to 16 countries, causing severe damage to banana crops.

To effectively combat this devastating disease, a training workshop on “Banana Bunchy Top Disease Awareness and Management” was held from June 17-21, 2023, in Dar es Salaam, Tanzania. The workshop, sponsored by the Current and Emerging Threats to Crops Innovation Lab, was attended by 40 participants from various organizations, including the International Institute of Tropical Agriculture (IITA), Tanzania Plant Health and Pesticides Authority (TPHPA), district plant protection officers in affected areas, PlantVillage Tanzania via Dream Team Agro Consultancy Limited (a youth-led company), PlantVillage Kenya, PlantVillage Uganda and PlantVillage Malawi.

The workshop brought together researchers, entomologists, virologists, plant health inspectors, district plant protection officers, pathologists, machine learning engineers and agronomists with the aim of strengthening regional capacity in disease surveillance, diagnosis and the implementation of responses to eliminate infected plants. Hands-on training was provided on the application of on-field diagnostics for the detection of BBTV using the PlantVillage Nuru mobile app for real-time surveillance and reporting.

BBTV spreads through infected planting material and is also transmitted by the banana aphid, an insect vector. Lava Kumar, an IITA virologist, highlighted that the inadvertent distribution of infected planting material has contributed to the widespread occurrence of the virus in sub-Saharan Africa, as farmers often obtain planting material from their neighbors or their own potentially infected farms.

The disease stunts banana plant growth, leading to a halt in fruit production. Sometimes, all fruit is lost in a single season. Infected banana plants exhibit symptoms such as deformed leaves, often with yellow or orange discoloration.

“Farmers and extension officers are unaware of BBTD symptoms. It’s crucial that we train them regarding the disease symptoms and implement measures to prevent the spread of the virus,” commented George Mahuku, IITA plant pathologist.

When BBTD strikes, the recommended course of action for farmers is to destroy infected banana plants and replace them with healthy suckers. However, smallholders may hesitate to take this step, especially if some of their plants are still bearing bunches. Kumar underscored the importance of using clean, virus-free planting material to prevent the disease’s spread.

During the presentations, Dr. David Hughes, director of the Current and Emerging Threats to Crops Innovation Lab and an entomologist at Penn State University, provided insights on controlling banana aphids through integrated pest management practices.

Thadei Myungile, PlantVillage Dream Team director, Tanzania, shared updates on their initiative to convert infected banana plantlets to biochar.

Tracyline Jayo, a research-extension officer at PlantVillage Kenya, explained the differences between BBTD, fusarium wilt and banana Xanthomonas wilt (BXW) in terms of their modes of transmission. While BXW is caused by the bacterium Xanthomonas vasicola pv. musacearum, fusarium wilt is caused by the soil-borne fungus Fusarium oxysporum f.sp. cubense.

Participants also had the opportunity to visit three farmers whose fields were affected by BBTD in Ubungo District. Both the participants and farmers were trained in the use of the PlantVillage Nuru mobile application, which allows for rapid diagnosis and reporting of diseases from the field.

As part of the Feed the Future Current and Emerging Threats to Crops Innovation Lab initiative, efforts are underway to collaborate with IITA and contain the spread of BBTD and recover banana production in East Africa.