University of Arizona researchers search for new ways to protect lettuce from Fusarium wilt

YUMA, Ariz. (KYMA) - Lettuce growers in the Southwest are constantly battling challenges that can threaten an entire crop. One of those threats is Fusarium wilt, a soil-borne disease that can cause devastating losses in affected fields.

Researchers at the University of Arizona are testing new ways to fight the disease and give desert growers more options to protect their lettuce crops.

The research is taking place on 11 acres of test fields that have been dedicated to Fusarium research for nearly a decade.

The long-term research has created an environment with high disease pressure, giving scientists an opportunity to test potential solutions under difficult conditions.

"We've got trials set up in ground that has been dedicated to Fusarium research for almost a decade now," said Dr. Chris Detranaltes, an associate in extension in plant pathology with U of A Cooperative Extension. "So it gives us a unique opportunity to really test what we want to see may be effective against that disease in really high-pressure ground."

The research team is testing several strategies aimed at reducing the impact of Fusarium wilt.

One area of research focuses on genetic resistance. Scientists are evaluating lettuce varieties and breeding material to identify plants that may be better able to withstand the disease.

Researchers are also studying lower-cost fumigation methods that could provide growers with another tool for managing Fusarium in contaminated soil.

Another approach involves RNA interference, a biological strategy researchers are investigating as a potential way to limit the growth of Fusarium around lettuce roots.

The goal is to find treatments and management practices that are effective, while also being practical and affordable for commercial growers.

Fusarium wilt is caused by a soil-borne pathogen that can remain in the soil and threaten future lettuce plantings.

Researchers say affected fields can experience up to 100% crop loss when the disease takes hold.

Weather can also play a role in how severe the disease becomes. Hotter, unseasonal conditions can increase the impact, while cooler weather can reduce disease pressure.

For growers in the desert Southwest, finding effective ways to manage Fusarium is especially important because lettuce is a major part of the region's agricultural industry.

The U of A research team will continue testing different strategies in the field, with the goal of identifying solutions that can eventually make their way to commercial lettuce growers.

The research could help provide growers with more tools to protect their crops before Fusarium has a chance to take hold.