The California Association of Winegrape Growers' effort to abate sulfur drift has added promotion of more judicious use of high-risk herbicides to its proactive effort to knit understanding between growers and the public.

Joseph A. Browde, project coordinator for CAWG's Pest Management Alliance (PMA), explained how it is being done in a talk at the recent conference in San Jose of the California Weed Science Society.

Established in 2000, PMA is a partnership between wine grape growers and the California Department of Pesticide Regulation.

Its management group comes from the ranks of growers, university Cooperative Extension specialists, USDA, EPA, and others. It is funded by about $200,000 in grants from DPR, growers, and wineries. More than half of the PMA's activities are supported by voluntary, in-kind contributions.

Browde said the alliance came about as a result of wine grape growers increasing awareness of pesticide concerns that could threaten their businesses. He said it is committed to a sound, proactive approach to help sustain the industry.

Implementation of the Food Quality Protection Act, the increasing interface between agriculture and urbanization throughout the state, increased understanding of off-target movement of pesticides, and heightened concerns with worker exposure all brought about the public's mounting awareness.

‘Prepare for future’

“Growers realized they'd better get their act together and prepare for the future,” Browde said. The thrust was to consider the wine grape industry, the general public and the environment, simultaneously.

Tied in philosophy to several efforts, including the new Sustainable Winegrowing Practices, PMA fosters adoption of integrated pest management systems with various wine grape grower groups.

PMA is grower-driven and has a polished mission statement. “There have been reports of high-profile drift when it comes to sulfur dust across the state. We also want to minimize herbicide use that can influence water quality or are currently listed high on the priority list of FQPA,” Browde said.

Educating the general public in such matters is crucial to the sustainability of agriculture, he said. Sulfur became an issue as it emerged during 1997 to 1999 in 86 reports of sulfur drift handled by county agricultural commissioners throughout the state. Sixty-six of those reports pertained to grapes, and most of them were public complaints at the urban-ag interface.

A sulfur task force was formed in 1999 with registrants, who developed a supplemental label and a stewardship program for all sulfur products.

PMA is collaborating with the sulfur task force and specializes in the public education outreach to sensitive areas, those of human activity, he said.

Challenges

“The public has to realize the challenges of grape growing and pest management. We want the public to realize there are worst alternatives than sulfur. We believe if we get that part right, we can decrease public complaints.”

Browde said PMA is not out to eliminate products. “We just want to keep everything around so that uses are warranted and things are done most safely. Reduced risk practices are available and we want to get the word out to growers around the state.”

In its campaign relating to herbicides, CMA seeks to minimize risks from herbicides, which would include limiting use of “problematic” herbicides used in vineyards. Among those are several compounds under scrutiny for water quality or FQPA issues. Of them, only Roundup is listed as a lower risk material.

“Wine growers are concerned because not a lot is left off these lists. So, again, we are not saying not to use something but we are about keeping something in our arsenal where warranted.”

PMA surveyed grape growers across the state to learn what they consider lower risk practices. Principles included are good, scientific information on soils and weed species, the amount of weeds that are economic and can be left in the field, and the elements of reduced risk.

Among the reduced-risk practice alternatives for weed control are the venerable French plow and other machinery, mowing or mulching, heating or flaming, and use of subsurface drip irrigation.

Among practices for reduced chemical use are lower rates per acre either by swath width under vines, calibration adjustments, closer timing to target weed susceptibilities, and rotation with higher-risk materials.

“We want growers to become alert to what's going on in their fields. They won't have to use these every year, but maybe every second or fourth year.”

The alliance has been using field demonstrations, presented by growers, to get the word out to other growers at various sites up and down the state. All along, the group seeks to have “a rational dialog” with the public about these practices.

Browde said PMA has attracted support of major wineries, such as Kendall-Jackson, E & J Gallo, Mondavi, and Canandaigua, to “buy-in” with the effort with support.

Moving plans for the coming season, he said PMA is adding growers to showcase their reduced-risk vineyard practices and expand the educational base.

Growers and PCAs have been approached for input, the next step is Spanish-language presentations for workers, and a third element is heightened information to the public.

“The future is full of change — it always will be,” Browde concluded. “We want to make sure our growers know the options. Proactivity is the key, so we will continue to try to anticipate change, to be there to try to come up with solutions. If you are there, being proactive vs. reactive, you can be part of the change.”

e-mail: dbryant@primediabusiness.com