Bananas Under Threat

Molokai may be known for its fighting spirit, but a battle is going on that has nothing to do with development or politics — it’s a battle against a virus. Banana Bunchy Top is a disease that infects banana plants and threatens the operation of both commercial growers and the productivity of backyard gardens. Discovered on Oahu in 1989, Banana Bunchy Top Virus (BBTV) was first found on Molokai in 2005.

“It’s important not only to ag and commercial growers to have quality product, but for community members to always have good quality eating bananas for their own personal use,” said Lori Buchanan, coordinator of the Molokai/Maui Invasive Species Committee (MoMISC). “[If left untreated, BBTV] creates an infestation that will spread to neighbors and throughout the community and eventually you won’t have any healthy replacement stock for bananas.”

MoMISC, along with partner agencies, works to identify and control the disease in an effort to eventually eradicate it from Molokai. Working under the Research Corporation of the University of Hawaii, MoMISC’s team of field associates responds to pest reports, works to eradicate target pest species on Molokai like BBTV, surveys for new pests — such as coqui frogs and fire ants which have yet to invade the island — and provides invasive species community education.

They’ve recently been focusing on BBTV as the occurrence of the disease rises in central Molokai. MoMISC has established a containment area from Mahana to Kualapu`u and all of Ho`olehua, and regularly monitor for outliers that would indicate its spread, said Buchanan.

If left untreated, the impacts could be dire.

“The economic impacts to commercial ag growers is pretty significant,” said Buchanan, adding it also threatens the genetic purity of native Hawaiian banana varieties. “For backyard growers, they might be forced to purchase commercial product from the store when they notice a decline in production.”

Experts at UH agree with the forecast.

“Continued spread of BBTV is a significant threat to Hawaii’s banana industry,” states a UH CTAHR publication. “It is imperative that BBTV prevention occurs in both banana-producing agricultural areas and in the community at large.”

Sick plants look stunted, yellow and their growth is bunched up. Other signs of the disease include veins in the leaves forming a “J” shape by the leaf ribs, and striations in the leaf’s appearance.

“The virus is spread by the banana aphid,” wrote UH CTAHR Molokai Extension Agent Glenn Teves in a 2011 Dispatch article. “Just by feeding on an infected plant for 18 hours, the aphid can spread this disease for two weeks. By feeding on a new plant for just two hours, the plant can be infected.”

Along with early detection, treatment and control of diseased plants is key, said Buchanan. If the MoMISC team notices signs of infection, they will reach out to the property owner and ask for permission to treat the diseased bananas. Buchanan said if left untreated, the plant will eventually die anyway, but in the meantime, it creates an infestation of the highly contagious virus.

“Compliance is voluntary but be a good neighbor,” urged Buchanan. “When the plant dries up and dies [after treatment], you can dig it up and replace it” — which can take between two weeks and two months, depending on the size of the plant. Ensure you replant with healthy keiki, she said.

Buchanan said the best prevention is keeping your garden or farm clean and free of rubbish that can harbor pests. She suggested occasionally spraying banana plants with mild soapy water to discourage aphids, and regularly clearing dead growth from the plants.

“We’ve been working hard to keep it from spreading to other parts of Molokai and we can only be successful if those with infected plants cooperate by controlling it,” she said. “People need to be responsible for their own plants. It takes all of us working together to control the disease. If just one person is not doing their part to help in the effort, it’s all for nothing, we’ll never be successful in control and everyone suffers.”

If you suspect BBTV, call MoMISC at 553-5236 x 6585 and team members will identify the disease with either visual or lab-confirmed testing.