Warm greenhouse air gives life to spinach plants in the rainy Skagit Valley, but disease threatens that life. WSU researchers are figuring out how to stop the pathogen.

Ph.D. student Emily Gatch is working in the lab of plant pathologist Lindsey du Toit to detect and combat Fusarium wilt - a soil-dwelling microscopic fungus. The work is being done at the WSU Northwestern Washington Research and Extension Center in Mount Vernon.

Local farmers, nation depend on crop

“It’s important … that we are able to produce seed for growers throughout the country who are relying on spinach from Washington State," Gatch said. "If you’ve eaten bagged baby leaf spinach that you can get in the grocery store, chances are the seed for that crop came from this valley.”

Fusarium is devastating: Once soil is infected, spinach can’t successfully be grown in that field for up to 15 years. The disease has been responsible for a decline in land for spinach seed production in the Pacific Northwest.

“We need to … get the rotation interval back down from 15 to 16 years, to four or five someday, because we’re running out of ground,” said Kirby Johnson, president of the Puget Sound Seed Growers Association and a fourth generation farmer in the Skagit Valley.

Applicable to other crops too

The research starts with a bucket of soil from a field slated for a spinach seed crop. Gatch and du Toit have developed a greenhouse soil assay that indicates which soils are at high risk for Fusarium wilt.

Once soils are tested, locations where spinach can be grown safely are identified.

Many aspects of the disease in spinach seed crops are applicable to other crops also threatened by Fusarium wilts, Gatch said. If researchers understand the characteristics of the soil, that information might translate to other crops as well.

Tax dollars at work

Johnson said the work WSU is doing is important to the livelihood of growers and their families. Once further research is conducted, Gatch said the results will go a long way toward helping growers.

“It is hands on, actual tax dollars at work, that makes sense and makes money for the industry and for the farmers,” Johnson said. "It’s very important; it’s a big deal.”

Find more information about the spinach research here.