HONOLULU – The papaya ringspot virus (PRV) has made its way to the Island of Lana‘i. PRV has already established its presence on O‘ahu, Maui and the Big Island. It is a serious affliction of papayas that causes poor quality, ring-spot-blemished papaya fruits, and the eventual death of the plant. However, PRV is not harmful to humans, even if affected fruit is consumed. The disease is transmitted from infected papaya plants to healthy plants by aphids. There is no cure for the plant virus and affected plants should be destroyed.
The virus was first suspected on Lana‘i at a commercial papaya farm by an extension agent with the University of Hawai‘i College of Tropical Agriculture and Human Resources (CTAHR). Test samples were sent to Honolulu and confirmed as PRV. Subsequent surveys by HDOA staff have revealed that the virus is widespread in Lana‘i City in backyards and in the community garden.
The Hawai‘i Department of Agriculture (HDOA) and CTAHR will be scheduling a community meeting at a later date on Lana‘i to provide residents with information about the virus and control options.
In the meantime, Lana‘i residents are asked to check their papaya trees for symptoms of the virus, which include yellowing of the top leaves, shoestring-looking leaves, water-streaking on the petioles (leaf stalks) and ringspots on the fruit (see photos). If residents suspect that their trees have PRV, they should call either HDOA’s Maui Office at 873-3558 or the CTAHR County Extension Office on Moloka‘i at 567-6934 for instructions.
PRV was first detected on O‘ahu in 1945. In 1992, PRV appeared in the Puna District on the Big Island and proceeded to devastate the commercial papaya industry on that island, which grows about 90 percent of all papayas in the state. Researchers at CTAHR developed a genetically modified papaya that was resistant to PRV and farmers have been using the disease-resistant varieties to manage the disease on the Big Island. Maui had a short bout with PRV in 1974 but in 2002, the virus reoccurred on that island.
Kaua‘i and Moloka‘i are now the only islands that are not known to have the virus. Agriculture officials are asking the public not to transport papaya plants or plant parts from infected areas to non-infected areas. However, papaya fruit and seeds may be transported.