Extension - Alfalfa and Grass Hay Pest Management
PI(s): Youngman, Roger R
Investigators: Mize, Tim, Love, Kenner , Laub, Curt
Website: Virginia Alfalfa IPM Source
Abstract: Alfalfa serves as a high quality source of feed for the beef and dairy cattle industries in Virginia. A total of 110,000 acres of alfalfa were grown in Virginia in 2005, which produced 396,000 tons of hay valued at $50 million (2006 Va. Agric. Statistics Bull.). Grass hay production is another important livestock feed for Virginia. In 2005, grass hay production on 1.2 million acres produced 2.6 million tons of hay valued at $270 million. Alfalfa weevil and potato leafhopper are the main insect pests on alfalfa, whereas bluegrass billbug and Japanese beetle (one of the most damaging of the annual white grub species) are the main pests on grass hay and pasture fields. Grass hay pest management represents a new direction for my lab. This is largely in response to the bluegrass billbug and Japanese beetle outbreak on tens of thousands of acres of Virginia orchardgrass in 2005.
Description: Program Outcomes: The Virginia Alfalfa IPM Source web site, which was completed in 2005 and co-developed with Mr. Curt Laub, addresses the IPM needs of anyone interested in better managing insect pests on alfalfa. The website contains eighty-eight separate pages in addition to numerous photos and illustrations. Comprehensive sections on insect identification, life history, feeding injury, scouting techniques, and biological and other control methods are devoted to alfalfa weevil and potato leafhopper. The Virginia Alfalfa IPM Source web site has been submitted for formal peer review. A recently completed three-year field study showed that a commercial leafhopper-resistant alfalfa variety did not provide acceptable levels of potato leafhopper resistance. This particular leafhopper-resistant variety, which was sold at a premium for such purpose, is no longer being marketed by the parent company. Our cost-benefit analysis work indicated that growers who planted this ineffective leafhopper-resistant variety lost nearly $31 more per acre than a grower who planted a standard, non-leafhopper resistant variety. A fall 2005 survey on over 800 acres of orchardgrass in northern Virginia indicated that these acres sustained damage of 40-100% from bluegrass billbug and Japanese beetle. Orchardgrass, bluegrass, and timothy hay make up about 35% (451,500 acres) of the grass hay acreage in Virginia (2004 Va. Agric. Statistics Bull.). The estimated annual value of these acres to producers is $158 million (based on 451,500 ac x 2.5 tons/ac x $140.00/ton). Given these figures, and assuming a 40% economic loss per acre, the statewide loss in lower yields and replanting costs is conservatively estimated at $63 million for 2005. Field trials conducted in 2006 and 2007 have produced useful information that Extension agents are using to educate hay producers on the best approach to managing orchardgrass insects. Relevant findings are being used to update future editions of the Virginia Cooperative Extension Pest Management Guide for Field Crops. Additional outcomes include my contribution to two articles written by Lora Berg of Hay and Forage Grower on the 2005 bluegrass billbug and Japanese beetle outbreak. These articles were published in the February 2006 issue and are entitled: Billbugs chomp on grass hay, eastern growers suffer heavy losses, and Insects and diseases cause headaches for grass hay growers. Hay and Forage Grower is a trade journal publication with a current circulation of 82,000.
Commodities: Alfalfa, Forages
Resources: 3-D Insects, Computer Workstations, Department Shop, Entomology Laboratory - Southern Piedmont AREC, Insect Identification Laboratory, Insecticide Storage Building, Price Hall, State-Owned Vehicles, Virginia Tech Pesticide Programs
Disciplines: Environmental Quality, Integrated Pest Management, Pesticides
Audiences: Agribusiness, Commodity Groups, Government Agencies, Graduate Students, Local Governments, Producers, Prospective Students, Researchers
