The University of California-Davis has released five new high-yielding strawberry varieties that are resistant to Fusarium wilt, a deadly soil-borne disease.

The new varieties — UC Eclipse, UC Golden Gate, UC Keystone, UC Monarch and UC Surfline — are now available for sale in California nurseries. The new varieties are meant to replace disease-resistant ones such as Monterey, UCD Royal Royce and UCD Valiant.

UC-Davis researchers developed the varieties by selectively breeding for wilt-resistant genes.

“These (new varieties) provide the same yield or better and they are Fusarium resistant,” said Steve Knapp, a UC-Davis professor and director of the UC-Davis Strawberry Breeding Program.

For many years, Fusarium wilt has been a serious problem for growers in California, which produces about 1.8 billion pounds of strawberries a year, representing about 88% of all strawberries harvested in the U.S.

The pathogen, according to a research paper published in the journal of Theoretical and Applied Genetics, also affects other regions around the world and is considered “one of the most destructive plant-pathogenic fungi worldwide.” It causes susceptible plants to wilt, collapse and die.

Fusarium wilt became a serious threat to the state’s strawberry crops after the U.S. phased out use of the fumigant methyl bromide in 2005. Since then, Fusarium wilt has rapidly spread.

“The disease has taken off fast and we need to react quickly to address to the need,” said Glenn Cole, a breeder and field manager with the UC-Davis Strawberry Breeding Program.

According to the California Strawberry Commission, no effective post-plant control exists for Fusarium wilt, so growers cultivating strawberries in diseased fields have to “rely on disease-resistant varieties.”

Yet according to UC-Davis, 55% to 59% of strawberry varieties planted in California since 2014 have not been resistant. The April release gives growers more options for varieties to plant.

Each of the new varieties has its own flavor and characteristics.

Eclipse is a “summer plant” cultivar, meaning growers plant it in the summer. It has the potential to increase grower profitability as it produces strawberries in the fall and winter. Initial research from UC-Davis shows the yields were 54% higher than those of similar cultivars.

“We expect this cultivar to have wide commercial appeal,” said Knapp.

Golden Gate and Keystone are “day neutral” varieties, meaning they are not sensitive to the length of the day and continue to flower and fruit when temperatures are moderate.

Surfline and Monarch, which are “short-day” varieties, are resistant to Verticillium wilt and Phytophthora crown rot in addition to Fusarium wilt.

Surfline and Eclipse varieties are firmer and should have longer shelf lives.

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