A newly designed smartphone application is offering backyard growers an opportunity to find out whether their papaya plants are infected with the destructive papaya ring­spot virus.

A mail-in service will inform them whether the papaya are genetically engineered.

The free app, available for iOS and Android users, was developed by Scot Nelson and Richard Manshardt from the University of Hawaii at Manoa’s College of Tropical Agriculture and Human Resources as part of their Pic-a-Papaya proj­ect.

The scientists note that the virus, first discovered in the 1940s, devastated the papaya growing industry in Hawaii to the point that Big Island commercial growers were losing half of their crops to the disease by the 1990s. The spread of the disease was checked and eventually reversed by the development of the Rainbow and SunUp papaya strains, which were genetically engineered to resist the disease.

With the new app, available via the Pic-a-Papaya website, www.ctahr.hawaii.edu/pic-a-papaya, allows growers to take pictures of plants from Hawaii Kai to Kapo­lei and send them to be checked for the ring­spot virus. Each plant will be categorized as "healthy" or "diseased" and included on a GPS map that shows the distribution of infected plants.

People are also invited to find out whether their papaya plant is a genetically engineered variety by sending a leaf sample to the scientists for examination. Instructions are available at the Pic-a-Papaya website.

Growers who wish to replace their virus-infected or genetically engineered plant can receive their choice of nongenetically engineered seed with partial virus tolerance or virus-resistant Rainbow or SunUp seeds via the project.