Buyers in Asia and Europe have shunned U.S. wheat since USDA announced last week that a strain of wheat, modified by Monsanto Co for herbicide tolerance, was found in an Oregon field. Genetically modified wheat is not approved for cultivation anywhere in the world.
Vilsack said development of a reliable, low-cost test for GM wheat was an Agriculture Department priority. Asked how soon a test would be available, Vilsack said, "Obviously, as soon as we can do it."
Current tests are expensive and time consuming, and the new test is intended to be quick and easy.
Vilsack's remarks, on the sidelines of a USDA event focused on cutting down food waste, were his first public comments on the subject since the GM wheat find was announced on May 29.
USDA officials have said daily there are no signs GM wheat was in commercial channels. Vilsack said development of a rapid test would allow grain exporters and processors to assure customers that their products are safe to eat.
With that assurance, he said, "The markets will be re-opened."
Japan, South Korea and the European Union have said they plan to test incoming wheat shipments for GM wheat. Preliminary tests by Korea on U.S. wheat and flour were negative, officials said on Monday. Final results are expected on Wednesday.
USDA was in "ongoing communication" with trading partners and customers about the investigation, said Vilsack.
Two approaches are available for a GM wheat test, said Vilsack. One test, used on corn and soybeans, examines protein in crop. The other method is a DNA test.
USDA's other priority is to find the source of the GM wheat that sprouted in the northeast Oregon field. The unwanted "volunteer" seedlings survived when sprayed with the weed killer glyphosate, which led to tests that identified the wheat as a Monsanto strain.
Other fields on the farm tested negative for the wheat, said a USDA spokesman.
Some $9 billion in U.S. wheat exports hang in the balance. The United States, the world's largest farm exporter, exports nearly half of its wheat crop.
