(Photo by Amanda Solliday - KAWC)

Representatives from Takii Seed plant lettuce by hand for the resistance trial.

(Photo by Amanda Solliday - KAWC)

Martin Porchas, a research specialist with the University of Arizona, adds lettuce seed to a vacuum planter.

(Photo courtesy of Michael Matheron - University of Arizona)

The fusarium fungus enters the plant through the roots, causing lettuce to wilt or die.

Fusarium wilt — a lettuce disease caused by a soil-dwelling fungus — is becoming a more common problem in fields. The disease causes lettuce to droop and turn brown, making it unsuitable for sale.

Typically, when lettuce wilt appears, the grower would then rotate to another crop like broccoli or cauliflower. But one farmer in Yuma dedicated three acres of his troubled field to research led by the University of Arizona.

MORE: Wilting Disease Threatens Arizona's Lettuce Crop

UA last conducted a test of resistant lettuce varieties 13 years ago in a field known to contain the disease. Since then, plant breeders have created new types of lettuce designed to elude fusarium wilt.

In the test field, scientists and seed company representatives hope the resistant varieties will appear healthy, but the researchers also want to see some sick plants to verify the presence of the disease.

“If the crop is successful, half of this lettuce or more will be dead," said Victor Heintzberger, the president of Vanguard Seed.

Heintzberger traveled from Salinas, California, to test some of the varieties his company is developing. He said a field trial like this is an opportunity to verify results seen in the lab.

And there’s a little bit of friendly competition to see who will have the best-looking lettuce.

“I’m expecting to see one bed here totally green all the way though. And that will have a Vanguard Seed flag on it," Heintzberger said.

Heintzberger wants to see the successful lettuce from his company commercially available as soon as next year.

The lettuce trials will be on display during November’s Fusarium Wilt of Lettuce conference, hosted by the University of Arizona’s Yuma Center of Excellence for Desert Agriculture.

EDITOR'S NOTE: This story has been updated to clarify the institution leading the research.

Updated 9/22/2015 at 1:45 a.m.