Scientists with the University of Florida have secured a $5 million grant from the U.S. Department of Agriculture National Institute of Food and Agriculture to combat the lethal Laurel wilt disease and the redbay ambrosia beetles responsible for it.
The research aims to improve control and mitigation practices for avocado production in Florida. The grant also will support the testing of new varieties for their tolerance to cold and disease. This initiative is poised to extend avocado cultivation beyond Miami-Dade County, fostering growth and sustainability beyond the Sunshine State’s avocado production industry.
“Laurel wilt is the most devastating disease to avocado trees in the world,” said Jeffrey Rollins,principal investigator and a professor of plant pathology at the UF Institute of Food and Agricultural Sciences, who’s leading the research team. “Trees infested with this pathogen die within four to eight weeks.”
The pathogen is transmitted to trees by four to five ambrosia beetle species and through root grafts of adjacent avocado trees.
“Growers are interested in increasing commercial acreage in Central Florida, thanks to a variety of conditions, one being warmer climates shifting to the north. Currently, avocados can be found growing as far north as Polk County,” said Jonathan Crane, a co-principal investigator and a tropical fruit crop specialist at UF/IFAS Tropical Research and Education Center. The grant will support research to expand the market.
However, the South Florida avocado industry has been severely impacted by Laurel wilt with production reduced by about 50%, he said.
Laurel wilt was first detected in Florida’s commercial avocado production area of Homestead in 2012. Initially, the disease was spread by one species of the redbay ambrosia beetle, Crane said.
“The pathogen has now spread to 10 ambrosia beetle species, five of which we know can transmit the disease,” he said. “That completely complicates everything. There is more at stake because the problem stretches beyond Florida into other avocado-producing states, posing significant risks.”
The disease has destroyed over 350,000 avocado trees in Florida, Rollins said.
“We are working to avoid what could be an ecological disaster as the beetle also attacks native trees in the Laurel Family as well as avocado trees,” he said.
This significant funding amount will support a trans-disciplinary research team of 12 scientists across the state, leading efforts for the next five years that is aimed at sustaining the Florida avocado industry and expanding avocado production both in South Florida and into Central Florida to accommodate the increased demand.
Meanwhile, UF/IFAS scientists have developed several mitigation efforts and best practices. The new grant will enable UF/IFAS researchers to explore additional innovative pest-management techniques, plant breeding, modeling and genetic solutions to mitigate the impact of this disease.
“The industry is battling the Laurel wilt disease with proven pruning practices to open the groves to increased light and wind, which suppress the ambrosia beetle activity,” Rollins said. “Some growers are injecting fungicide to reduce tree losses, and many growers are replanting lost avocado trees.”
California, home to 90% of avocado production in the United States, is valued at more than $1.6 billion, Rollins said.
“As this disease progresses, its environmental impact grows, attacking native trees and numerous members of the Laurel plant family,” Crane said. “The disease has caused substantial economic losses and has threatened the viability of commercial avocado production.”
By finding cost-effective measures to manage Laurel wilt, researchers seek to ensure the continued sustainability of avocado production that Florida has enjoyed and beyond, he said.
Meanwhile, UF/IFAS researchers have reported an increase in acreage in Central Florida dedicated to avocado cultivation that is in response to the growing demand for avocados in this region.
The development of cold-tolerant avocado varieties as part of the grant’s initiative has the potential for growers in Central Florida to expand their operations.
With its world-class expertise in agricultural research, UF/IFAS researchers are committed to ensuring that Florida avocados thrive and expand despite the challenges posed by Laurel wilt.
“This project represents a significant step forward in safeguarding the state's agricultural heritage and the livelihoods of those who depend on it,” Rollins said.