New York Farm Viability Institute Website Press Releases 

PRESS RELEASE: November 20, 2006

Contact: Gary Couch, NYS IPM Program, 845-344-1234
Jpg: John Barone of Barone’s Gardens is ready for a holiday sales of poinsettias.

Greenhouse Growers Gain Against Fungus Gnats;
NYFVI-Funded Project Tests Protection of Poinsettias and Bedding Plants

Syracuse, NY -- As the holiday season approaches, flower shops, garden centers and supermarkets fill with brightly-colored poinsettias. About 3.4 million potted poinsettias are wholesaled by New York growers annually. To increase his bottom line from holiday sales, John Barone of Barone Gardens, a retail garden center and commercial greenhouse in Cicero, NY, wanted to propagate his own poinsettias using integrated pest management to control fungus gnats that damage plant quality. With funding from the New York Farm Viability Institute, Inc., Syracuse, NY, Barone teamed up with Cornell Cooperative Extension Ornamental and Community Integrated Pest Management (IPM) Specialist Gary Couch on research into IPM options to protect bedding plants and poinsettias.

Couch says, “We suspect that many disease problems in greenhouses are due to high fungus gnat populations. This New York Farm Viability Institute-funded project allowed us to test various biological controls to prevent outbreaks and to examine scouting methods to help growers detect fungus gnats in their greenhouses,” says Couch.

The larvae of fungus gnats can arrive at greenhouses in bagged soil mixes; the insects can overwinter in greenhouse floors, and adult gnats can fly in during the growing season. Some pesticides do not work on adult gnats; others work only at higher doses. Integrated pest management offers growers environmentally-friendly control measures that can be effective while reducing costs and human contact with pesticides.

For the NYFVI-funded research, when larvae were found at Barone Gardens and other participating greenhouses, the growers released nematodes or applied Gnatrol, a bacteria-based product. When adults were found, growers released predacious mites. Couch says the research work was a step in the right direction for bedding plant growers who saw fluctuating populations of the gnats with reductions at times of IPM applications of 51 to 71 percent.

“A combination of alternative products can provide acceptable pest numbers from a technical perspective, but more work is needed to enhance the opportunity for success, such as pinpointing infestation sources, and developing better larval scouting methods.” Couch says.

Barone says the project produced some good news and some temporary disappointment.

“As we tracked the bedding plants, we learned that controlling moisture levels was really what helped keep the gnat population down, so the good news is we uncovered a control method that will work without the added treatment costs. The bad news is that the methods we tested to help protect the poinsettias did not produce the hoped-for results.”

Still Barone has not abandoned hope that an IPM method can be developed for the popular holiday plant in the future. He says as a result of the NYFVI-funded project he has adjusted his business plan, and for now will sell potted poinsettias started by a wholesaler, but finished in Barone’s greenhouse and he will look at propagating his own poinsettias again in the future.

As a group, the greenhouse project participants are interested in evaluating the use of screening and air curtains to prevent gnats from entering greenhouses and post-infestation mass trapping and the use of sticky tape collectors.

The New York Farm Viability Institute, Inc. is a farmer-driven, nonprofit corporation that funds research, extension and innovative technologies for New York’s agricultural/horticultural producers. Projects must directly benefit producers at the farm business level. Contact: New York Farm Viability Institute, Inc., 159 Dwight Park Circle Suite 104, Syracuse, NY 13209, 315-453-3823, www.nyfarmviability.org. # # #