The University of California Statewide Integrated Pest Management Program (UCIPM) has teamed up with growers, ornamental plant organizations and industry personnel to develop integrated pest management strategies to protect a $300 million cut flower industry in California.
California is our country's largest producer of gerbera flowers, one of the most popular ornamental flowers in the world with more than 200 varieties, according to the California Cut Flower Commission. Gerbera growers often spray pesticides to control pests such as leafminers, whiteflies and thrips. With funding from UCIPM and other organizations in the Gerbera Pest Management Alliance (GPMA), researchers are investigating ways to improve the timing for releasing natural enemies, integrating biological controls and using reduced-risk pesticides to control destructive pests. A key concern is to determine how many pests are present and the number of pests it takes to impact crop yields so that growers can skip treatments when they are unnecessary.
Four 10,000-sq.ft. sites in Encinitas, Carpinteria, Ventura and Watsonville, Calif., are being used to develop standardized sampling methods and thresholds for gerberas. Without knowing how different numbers of pests affect a crop, growers don't know the best time to spray pesticides or to release natural enemies, which can result either in crop losses or excessive control costs. With science-based information on pest pressure and risk gathered in these experiments, growers will have a better understanding of when to apply natural enemies or pesticides so they can obtain the best possible pest control and reduce pesticide use, according to the Commission.
Researchers studied climatic factors such as temperature and humidity and non-climatic variables such as variety and leaf age to help determine optimal pest management practices. When complete, this study will serve as a model system for cut and potted floriculture crops statewide.
"The Gerbera Pest Management Alliance has been designed to advance integrated pest management and biological control strategies for gerbera growers wherever they may fall on the pest management continuum," says UC Davis entomologist Michael Parrella, who is one of the investigators of the project. "We have some growers who are actively using biological control, while others are just starting. This program, based on developing solid sampling strategies, will offer all growers the opportunity to advance their integrated pest management. We meet three times a year at a cooperating grower's packing shed, review progress of the GPMA, share experiences and tour the gerbera production area."
Other GPMA members are the California Cut Flower Commission, the California Department of Pesticide Regulation, county advisers, allied industry personnel and manufacturers of reduced-risk pesticides. The California Cut Flower Commission, the Hansen Trust, USDA (via the National Floriculture & Nursery Research Initiative) and the American Floral Endowment are also provided funding.