Use of special pesticide OK'd
By Kevin Dayton
Advertiser Big Island Bureau
HILO, Hawai'i — State agricultural officials have won emergency federal approval to use a special pesticide they hope will kill off the aphids that are spreading the banana bunchy top virus in East Hawai'i.
Nilton Matayoshi, chief for the chemical/mechanical control section in the Department of Agriculture's Plant Pest Control Branch, said the pesticide, sold under the trade name Provado, should reduce the threat the virus poses to the state's $8.4 million banana industry.
Other pesticides must be sprayed directly on the aphids to kill them, but Provado is sprayed on the plant and absorbed into it, killing the aphids when they eat the plant, Matayoshi said.
"That's something that we just didn't have all these years," he said. "We think the growers have a really good chance of stopping the spread of this vector."
The virus was first discovered in the prime banana growing region of East Hawai'i in early April, and agricultural inspectors confirmed cases of the virus on the 200-acre Kea'au Banana Plantation and in four other smaller patches of banana plants in the Kea'au area.
Suspicious-looking plants from Kurtistown and Kaiwiki are being tested for the disease, although those cases have not been confirmed.
Agriculture officials announced on Friday that they have confirmed bunchy top infections in wild roadside banana patches in Hala'ula, Kapa'au and Hawi in North Kohala, and asked that anyone who has moved banana plants out of the Kohala area in the past three years call the department so that agriculture officials can trace the plants.
The virus essentially wiped out farming of the popular Williams banana variety on O'ahu and presents a major threat to the Big Island crop.
Infected plants suffer severely stunted growth in the plant crown, resulting in a bunchy appearance.
Younger leaves are stunted with yellowish edges and may curl upward. Lower leaf stems and midribs have dark, parallel streaks that may form a continuous line or appear as intermittent blotches.
The virus is spread by the banana aphid or by people moving and planting infected young plants. Infected plants produce deformed and stunted fruit, and in advanced stages of the disease the plants do not produce any fruit. The virus is not harmful to humans who eat the fruit.
The U.S. Environmental Protection Agency granted the Agriculture Department an emergency exemption from restrictions on the use of Provado to try to control the spread of the aphids.
Although the insecticide is used against a variety of pests, it is not currently labeled for general use on banana plants, according to state agriculture officials.
The exemption allows the use of the pesticide on banana plants only in East Hawai'i by certified applicators.
Matayoshi said fruit from plants treated with the chemical will be safe to eat.
Big Island property owners who suspect that their banana plants may have the disease should call the Hilo office of the Department of Agriculture at (808) 974-4140.
Reach Kevin Dayton at (808) 935-3916 or kdayton@honoluluadvertiser.com.
