By Brad Buck
Organic food sales topped $50 billion in the United States in 2018. Statistics from the Organic Trade Association tell part of the story of this growing market: Fruits, vegetables and other specialty crops combined to make up 36.3% of total organic sales — up 5.6% from the previous year.
Naturally, farmers want to meet consumer demand. But they may need to use essential oils to battle pests and diseases that often accompany organic crop growth.
That’s why the U.S. Department of Agriculture National Institute of Food and Agriculture awarded a nearly $2 million grant for a project led by Ali Sarkhosh, a UF/IFAS assistant professor of horticultural sciences at the main campus in Gainesville.
Sarkhosh and a team of 14 other scientists from five universities and the USDA Agricultural Research Service (USDA-ARS) will study the degree to which essential oils can help suppress certain pests and pathogens.
Researchers from the University of Florida, Clemson University, the University of Georgia, the University of California-Riverside, the University of Hawaii at Manoa and the USDA-ARS will collaborate on the project.
“Due to long periods of warm temperatures and high humidity that are characteristic of Florida, Hawaii, Southern California, Georgia, South Carolina and other parts of the Southeastern United States, diseases are common,” Sarkhosh said. “Therefore, organic production of fruit crops in these regions is difficult because diseases cannot effectively be controlled without synthetic pesticides. This project will evaluate the plant safety and horticultural impact of essential oils (EOs) for disease management and will begin to test plant disease efficacy claims of EO products currently marketed for organic producers.”
Funding for the four-year research program will support scientists with expertise in fruit crop management and physiology, plant pathology, entomology, postharvest biology and organic production.
In the project, scientists will:
• Evaluate the plant safety and horticultural impact of essential oils in managing diseases in fruits including blueberries, peaches, mangoes and avocados.
• Begin to test plant disease efficacy claims of essential oil products marketed for organic producers.
• Evaluate organically certified plant essential oils on targeted pathogens such algal stem blotch, anthracnose, brown rot, scabs, gray mold and powdery mildew.
• Determine the efficiency of essential oils on fruit shelf life through postharvest testing.
• While arthropod pests are not the primary focus of this research, researchers also will test the efficacy of essential oils against insects including scales, thrips and mites.
Included among the 15 scientists who will work on the project nationwide are nine UF/IFAS researchers. They’re based at the UF/IFAS campus in Gainesville and Tropical Research and Education Center (TREC) in Homestead:
• Jeffrey Brecht, professor of horticultural sciences.
• Philip Harmon, professor of plant pathology.
• Danielle Treadwell, associate professor of horticultural sciences.
Among other duties, Crane will bring data from the research to the tropical fruit industry.
“This research is important because there is little to no science-based information on the efficacy and safety of most essential oils in pest management of fruit crops, including mango and avocado,” Crane said. “Only armed with sound data we can make recommendations to commercial producers on their use and crop safety.”
After they gather their new data, scientists will communicate results of their research to those who grow organic fruit as well as those who grow conventional crops so those producers can rapidly adopt the practices. Scientists will also evaluate the effectiveness of the project through continuous feedback from stakeholders.
“Organic fruit growers in the United States are often hesitant to embrace organic practices due to the shortage of tools for disease management,” Sarkhosh said. “The long-term goal of this project is to provide U.S. organic fruit growers with safe, organically certified compounds for disease management, and consequently improve their confidence in plant-based fungicide, bactericide and insecticide applications.”