Winegrowers to Vote on Pest Control

Renewal of Pierce's disease funding may include additional grapevine pests

by Paul Franson
Glassy Winged Sharpshooter
Government agencies and the wine industry have invested millions to combat the glassy-winged sharpshooter, vector of the often fatal-to-grapevines Pierce's disease.

Sacramento, Calif. -- We haven’t been hearing much about Pierce’s disease and the glassy-winged sharpshooter of late, and it seems other new vineyard pests like the light brown apple moth, European grapevine moth and vine mealybug are grabbing all the attention.

But that’s largely because government agencies and others are spending about $20 million to contain the GWSS and conduct research to find a permanent solution to the problem, which can be lethal to grapevines.

In the spring, winegrape growers will have a chance once again to vote on whether to assess themselves up to $3 per $1,000 of crop value to continue the research. This assessment only accounts for about $1 million of the $20 million. Significantly, this year, the board will be able to spend research funds on pests other than sharpshooters, too.

Ken Freeze, who heads outreach and education on behalf of the PD/GWSS board in California, says that 74% of the allotted funds come from the U.S. Department of Agriculture for control programs. The USDA set the battle line for containment to south of southern San Joaquin County.

Since 2000, a total amount of $371 million has been spent or allocated for PD/GWSS research, control and eradication by the federal and state government and industry. This includes pilot projects, the Grapevine Loss Assistance Program, the Nursery Pest Mitigation Program, research and other activities.

Freeze notes that progress is being made, although setbacks continue to occur, too. On Sept. 29, an adult glassy-winged sharpshooter was trapped about a half mile outside of the Branham infested area in San Jose, Santa Clara County. As of Nov. 6, the delimitation survey done by Santa Clara County officials revealed a total of 26 infested properties.

More positively, it appears that the Foothills Farms area in Sacramento County will be declared free of the pests, reducing infestations to 12 counties in California.

Even more promising for a possible permanent solution to the problem: Researchers have found a molecule that allows vines to coexist with the bacteria that causes PD by preventing it from growing in vines. This is undergoing trials, and more study is needed.

Renewing the assessment on growers should help find a solution to Pierce’s disease. It has been in place since 2001. Each year the PD/GWSS Board makes recommendations to the California Department of Food and Agriculture to set the rate of the assessment, which by law can be no greater than $3 per $1,000 of value of winegrapes. The assessment rate is generally set during the summer, just before most of the harvest for that year takes place.
The level has dropped since it was originally established:

2001: $3 per $1,000
2002: $2 per $1,000
2003: $2 per $1,000
2004: $2 per $1,000
2005: $2 per $1,000
2006: $2 per $1,000
2007: $1.50 per $1,000
2008: $1 per $1,000
2009: $1 per $1,000

Gallots for growers should be mailed by March 29 and results announced June 15.

The tabulation is complex and is based both on results from growers and the value of their crops. Growers with more than one plot receive more than one ballot, and each is counted separately.

If you are a California winegrape grower who produced and sold winegrapes during 2009, you are eligible to vote in the upcoming referendum. Be sure to fill out and return all ballots mailed to you.

Freeze points out that one of the reasons the federal and state government is willing to spend money to eradicate or at least control the sharpshooter is that the industry has been willing to pay its share, too. He also notes that California’s citrus industry, also vulnerable to GWSS/PD, has seen the successes of the grape effort and is establishing its own control board to fight a new citrus pest.


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