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70 p r a c t i c a l w i n e r y & v i n e ya r d a U G U S t 2 0 1 4 S onoma County has 60,000 acres of wine grapes, which comprise 6% of its land area. Since that 6% of land area generates approximately 70% of farm gate revenues, wine grapes are critical to the preservation of agriculture in the county. There are approximately 1,500 vine- yard owners in the county, and 40% farm less than 20 acres, while 80% farm less than 100 acres. Wineries farm approxi- mately 21,000 acres, with independent growers farming 49,000 acres. Sonoma County is a very environmen- tally sensitive community, with many current residents having little or no agri- cultural background or experience. Pesticide use in vineyards often attracts scrutiny from the general community and vineyard neighbors. This scrutiny has actually increased as unprofitable apple orchards have been planted to grapevines. While apple production did not attract much community concern, the vineyards that replaced those apples did. It should be noted, however, the envi- ronmental footprint for apple production is typically greater than for vineyards due to the increased need for insecticide use in apple production. The Sonoma County Grape Growers Association (SCGGA) launched a series of grower education programs about integrated pest management (IPM) beginning in 2000 with the initial goal of decreasing the use of chemicals as part of the Food Quality Protection Act (FQPA). Another goal was to increase IPM strate- gies in grape production that might lead to decreased pesticide usage. (A winegrape commission was formed in 2006, replacing SCGGA. The organization is now called Sonoma County Winegrowers.) Due to interest in organic pest-manage- ment options, an organic producer group was formed. The group met in a different host vineyard each month. The host dis- cussed pest management methods used in organic production and the successes or challenges they encountered. Forty to 50 growers typically attended, most of whom were not organic producers but were interested in incorporating some organic production methods into their vineyards. Many grower meetings rely on grower- to-grower education. Growers large and small share their successes and failures. They ask questions of each other, and expe- riences within the group provide answers or options. When a respected grapegrower neighbor tells of his or her experience in managing a pest in new ways or with new products, other growers might adopt the new approach. Without these meetings, growers may have been more reluctant to give up a pest management technique that was working for a new approach. From 1998 to 2011, there was a 40% reduction in the weight of chemicals applied and a 38% reduction in acres treated in Sonoma County. While the number of grape acres increased by more than 10,000 acres, the total weight of pesticide applied decreased from just less than 4 million pounds in 1998 to 2.36 million pounds in 2011 (Fig- ure 1). Note that sulfur comprised approx- imately 75% of total pounds of pesticides applied during that period. Pesticide application other than sulfur remained nearly constant. However there Improving pest management practices SonoMA CounT y Bevill Vineyard Management mows cover crop at Vogenson Vineyard in Dry Creek Valley. 4,500 4,000 3,500 3,000 2,500 2,000 1,500 1,000 500 0 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 Pounds Applied Years Pes cide Usage Total Pounds x 1,000 Sulfur Pounds x 1,000 Other Pes cides x 1,000 Figure 1. Pesticide usage trends in Sonoma County grape production from 1998 through 2011. Pesticide usage is from the California Department of Food and Agriculture Pesticide use Reports. Nick Frey BY