By Robin Koestoyo and Carolina Revilla-Vendrame
University of Florida officials recognized a team of research scientists with a High Impact Research Publication award for an article published in the May 2018 edition of Applied Microbiology and Biotechnology, an international scholarly science journal.
The publication, “Identification of the Achilles heels of the laurel wilt pathogen and its beetle vector,” introduces new pest management tactics for south Florida’s avocado growers. The industry’s value is $100 million-a-year to producers who are mostly in Miami-Dade County.
But every season, growers face ambrosia beetles that spread a fungal pathogen that causes a disease called laurel wilt. The disease wilts and then browns tree leaves, killing entire trees in only a few weeks.
Seven scientists and technicians with the UF Institute of Food and Agricultural Sciences (UF/IFAS) co-authored the honored paper. These scientists are committed to developing ongoing integrated pest management practices to protect the valuable commercial crop industry.
“The data reported in this paper supported simple recommendations to help control laurel wilt, advancing the scientific knowledge of this devastating disease,” said Sherry Larkin, associate dean for UF/IFAS Research and interim director for Florida Sea Grant. “This is one of many examples of how UF/IFAS researchers are providing real-world solutions for Florida farmers, and it was well-deserving of special recognition at our annual awards ceremony.”
The scientists and laboratory technicians who received the award work at the UF/IFAS Gainesville campus and at two UF/IFAS research and education centers.
Award recipients in Gainesville are Nemat Keyhani, a UF/IFAS professor of microbiology and cell science and Yonghong Zhou, a former postdoctoral scientist.
Daniel Carrillo, assistant professor of entomology and nematology and his biological scientist, Rita Duncan, conducted their work at the UF/IFAS Tropical Research and Education Center in Homestead, Florida.
Ronald D. Cave, professor and director of the UF/IFAS Indian River Research and Education Center (IRREC) in Fort Pierce Florida, along with Pasco Avery, a biological scientist and Alison Lukowsky, a technician, who both also work at IRREC.
Carrillo said the new information for avocado growers involves studies on the compatibility of common chemical pesticides, and an entomopathogenic fungus, Beauveria bassiana. Entomopathogenic fungi infect and kill only insects, and so pose no harmful threat to humans, non-insect wildlife or plants. The fungus not only kills the ambrosia beetles that carry the disease-causing pathogen, but also inhibit the pest’s ability to bore into the wood where it can spread the plant pathogen.
In a 2014 UF/IFAS news release, Brad Buck explains Carrillo and Avery’s recommended strategy to apply the fungus.
Avery used the fungus to determine its compatibility with agrochemical treatments in his laboratory. He said growers may access the 2018 compatibility studies at the following website: https://www.bioworksinc.com/products/shared/botanigard-es-tank-mix-compatibility.pdf
“Our studies are committed to resolving the laurel wilt dilemma with more precise management practices while the pathogen is still impacting trees, and to minimize the damage caused by the disease until we find a cure for laurel wilt,” said Keyhani.
Buck wrote about Keyhani’s contribution to UF’s recommended management practices in a 2017 news release. “The disease grows faster in the fall or winter than in the summer, so growers may want to look for laurel wilt more closely during the winter,” wrote Buck.
The award-winning publication presents a new tactic to manage healthy and productive avocado trees.
“Growers should maintain healthy soils and may consider adjusting the pH in their groves to greater than or equal to 6.8,” Keyhani said. “Because the fungus that causes laurel wilt is halophilic, it shows a dramatic decrease in growth at high pH values, and this could help in reducing persistence of the pathogen in soils, although effects on beetle-vectored transmission are likely to be minimal.”
Keyhani, Carrillo, Avery and Cave agree that biological control with entomopathogenic fungi is one of the best-known methods to manage ambrosia beetles that carry pathogens into avocado trees. The team of scientists is at work on other aspects of the same pathogen problem, seeking more of laurel wilt’s proverbial “Achilles heels” and newer management recommendations for avocado producers.
“Fungal entomopathogens are a tool that must be part of an integrated pest management program that includes cultural, chemical and other pest control methods that growers are using widely in Florida,” said Avery. “The growers are now at a point where the UF/IFAS strategies can allow them to have a more sustainable pest management program — despite laurel wilt.”
The mission of the University of Florida Institute of Food and Agricultural Sciences is to develop knowledge relevant to agricultural, human and natural resources and to make that knowledge available to sustain and enhance the quality of human life. With more than a dozen research facilities, 67 county Extension offices, and award-winning students and faculty in the UF College of Agricultural and Life Sciences, UF/IFAS works to bring science-based solutions to the state’s agricultural and natural resources industries, and all Florida residents. Visit the UF/IFAS web site at ifas.ufl.edu and follow us on social media at @UF_IFAS.