For generations, the papaya ringspot virus, or PRSV, threatened the livelihood of Hawai’i’s papaya farmers. It was discovered on O’ahu in the 1940s and devastated papaya production. By the mid-1980s, more than 90 percent of the state’s papayas were grown in the Big Island’s Puna district. The removal of infected trees in neighboring areas kept Puna virus-free for decades, but time was not on the growers« side. Knowing that Puna’s luck wouldn’t last forever, researchers from UH- Manoa’s College of Tropical Agriculture and Human Resources, Cornell University, the U.S. Department of Agriculture and private industry began work to develop a papaya genetically engineered to resist the virus.