Hawaii growers say they can now export more fruits and vegetables to the U.S. mainland thanks to research by agricultural scientists.

Tropical fruits and vegetables such as papaya, rambutan, longan, dragon fruit and purple-fleshed sweet potato are gaining popularity across the United States but have faced hurdles of strict quarantine restrictions and sanitary measures to keep agricultural pests from reaching the mainland, a release by the U.S. Department of Agriculture said.

Researchers working for the USDA's Agricultural Research Service have developed generic irradiation protocols found to control a wide variety of quarantine insect pests found on fresh produce, the release said.

Working with the USDA's Animal and Plant Health Inspection Service and Hawaiian growers and exporters, research service scientists found a generic dose of 150 grays of radiation was sufficient to control three species of fruit flies found in Hawaii, and a dose of 400 Gy is effective against many other pests.

The results convinced the USDA Inspection Service to approve the generic irradiation doses for treatment of Hawaiian produce.

Thanks to the research, it is now easier and less costly for Hawaiian growers to share their produce with mainland consumers, the USDA said.