Deadly disease wreaks havoc in banana fields, 23 districts confined

Dar es Salaam. Agriculture Minister Hussein Bashe said the government has quarantined 23 districts in 10 banana-producing regions following the outbreak of the destructive Banana Bunchy Top Virus (BBTV) infection.

The districts and their respective regions in brackets are: two (Kilimanjaro); one (Dodoma); one (Morogoro); one (Coast); and two (Dar es Salaam).

Others are four (Kigoma); three (Katavi); four (Mbeya); three (Mwanza); and two others (Geita).

BBTV was detected after conducting a delimiting survey in 15 banana-cultivating regions out of 31.

The study was jointly conducted by four institutions under the support of the United States Agency for International Development (Usaid), according to the summary report of the survey published in July 2023.

The institutions are the International Institute of Tropical Agriculture (IITA), the Tanzania Plant Health and Pesticides Authority (TPHPA), the Tanzania Agricultural Research Institute (Tari), and the Tanzania Horticultural Association (Taha).

Speaking on the government’s response to curb the fast-spreading banana killer disease, Mr. Bashe said the study was initiated by his ministry to determine the magnitude of the disease.

“Currently, Tari is collaborating with IITA in mapping areas infected with the disease. Infected plants will be uprooted and replaced with new seedlings for permanent control of the disease,” he said.

He said during the quarantine, plants infected with BBTD would be phased out and replaced with new ones produced through tissue culture.

About BBTD

This is an aphid-transmitted viral disease that was first reported in Buhingwe District, Kigoma Region, in 2021, with findings showing that infected plants display several symptoms.

They include stunting, bunchy growth with shortened petioles with chlorotic streaks and yellow leaf margins, as well as strict loss of harvests.

A team of 42 members from IITA, TPHPA, Tari, and Taha conducted the surveys.

Key findings

Study findings show that BBTV was detected in 10 regions out of 15 surveyed, with the exception of Arusha, Kagera, Manyara, Mara, and Tanga.

Furthermore, the document shows that monitoring in the five regions was ongoing using the BBTV crowdsourcing group.

“In Kilimanjaro Region, BBTV was detected in Moshi Municipal and Moshi Rural. The other districts (Hai, Mwanga, Rombo, and Siha) appeared to be free from the disease,” reads part of the document.

“Measures to continue monitoring the disease are in place using crowdsourcing. Local authorities, including DPPOs and extension officers, have been included in the crowdsourcing,” reads another part.

According to the study, BBTV was very severe in the Msaranga Ward in Moshi District, where the virus wiped out entire banana fields.

In those areas, farmers were reported to have abandoned banana farming and opted for alternate crops like maize and cassava.

The findings show that in Dodoma, BBTV was detected in Dodoma Urban following reports of a backyard garden that had BBTD symptoms after planting materials brought from a nursery in Morogoro Region.

“More districts in Dodoma should be surveyed to get the full extent of the disease in the region,” the report recommends.

The findings show BBTV was detected in Morogoro Urban only out of the three surveyed districts.

The findings show that the detection was made possible following a report from a farmer in Dodoma who observed BBTV symptoms in the suckers purchased from a nursery near the Morogoro-based Sokoine University of Agriculture (Sua).

“The survey team detected severe BBTD-symptomatic suckers in a nursery. The nursery operator confirmed that he sourced the planting material from Mzinga Ward in Morogoro Urban,” reads the report.

“The nursery has been selling banana seedlings to many farmers in Dodoma, Dar es Salaam, Mbeya, Shinyanga, and Mara regions. Farmers in Mzinga claim to have noticed BBTD symptoms since 2022, but they were unaware of the source,” reads another part.

According to the document, in the Coast Region, BBTD was detected only in Kisarawe District, with the remaining eight districts showing no symptoms of the disease.

The document shows that BBTD was widely distributed in the two districts of Dar es Salaam, namely Kinondoni and Ubungo.

“Most bananas are grown in backyard gardens as farmers bring planting material from rural homes. This is the most likely source of the disease in Dar es Salaam,” says the report.

The report shows that farmers reported seeing the disease in 2021, with Kigoma being the first place for the disease to be noticed and reported.

The document says the disease was widespread in Buhigwe and Kigoma districts, with all fields visited having plants infected.

The BBTD was detected in Uvinza District, indicating that the disease continues to spread southward, with Kasulu and Kibondo Districts being free from the disease.

“However, a suspected plant was observed in one field in Kakonko District, which was confirmed BBTV positive through a field diagnosis test.

“A repeat test will be organized for reconfirmation. Nonetheless, this result confirms a northward movement of BBTV,” adds the report.

The study also shows BBTD was detected in the three surveyed districts of Katavi Region, with plants showing symptoms in four districts of Mbeya Region.

BBTD was detected in three out of eight districts of Mwanza Region, with mild symptoms-like BBTD observed in one site in Misungwi District.

The symptom seen on a Matoke variety reported to be sourced from Rombo District in Kilimanjaro Region was later confirmed to be BBTV-positive.

The document shows that BBTD was found to be widely distributed, with all wards in Ukerewe District affected by the disease at 81 percent.

“In Kagera, eight districts were surveyed, and all were free from BBTD symptoms, and no BBTV was detected.

“In Geita, BBTD was detected in two districts: Geita Town Council (TC) and Geita Rural District Council (DC). The former was affected by 80 percent, and affected areas in Geita DC were identified to be near Geita TC,” according to the report.

According to the findings, the disease appeared to be spreading from urban to rural areas, and farmers reported seeing BBTD symptoms in Geita since 2019.

Following the trend, many farmers decided to replace banana fields with sugarcane, vegetables, and other crops.

Study recommendations

“Following the findings, the study recommended that top-level meetings be organized to build awareness among the government or ministries and mobilize resources for scaling up the fight against the disease.

The study also recommends the need to establish a functional banana seed system to curb the spread of BBTD and that a strategy to strengthen production and supply of clean planting material to farmers be developed and operationalized.

According to the document, this should go hand in hand with educating farmers to stop taking planting materials from neighbors and unverified sources.

“More surveys are needed, especially in the new areas, to delineate infected from uninfected areas and implement zoning to stop disease spreading,” according to the document.