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CDFA Begins Review of Grapevine Certification Program

Red Blotch Concerns Drive Revision Process
by Ted Rieger
December 19, 2014

The California Department of Food and Agriculture (CDFA) held its first public meeting December 18 in Sacramento to begin a review and revision of the California Grapevine Registration and Certification Program, driven in large part by wine and grape industry concerns about the potential presence of Grapevine Red Blotch-associated Virus GRBaV and leafroll viruses in certified nursery stock sold in California.

An audience of about 70 people representing grapevine nurseries, winegrape growers, Foundation Plant Services, viticulture consultants, researchers and testing laboratories provided a show of force to demonstrate the industry’s interest in revising and improving the program; however, meeting discussions also indicated that requirements of the rulemaking process could present challenges in expediting needed changes.

Joshua Kress, supervisor of the CDFA Nursery, Seed and Cotton Program, said CDFA plans to hold additional regional meetings to take industry and public input in early 2015, prior to beginning the formal rulemaking process, but he said no specific schedule has been set for future meetings. Kress provided an overview of the program and asked for public comment on specific issues related to current regulations.

Program Overview and Reasons for Review

The Grapevine Registration and Certification Program was started in 1956 and program regulations were most recently revised in 2010. The program is voluntary, with 31 California nurseries as approved participants in 2014. Participants apply to be in the program and pay fees for approval, and for regular inspection and testing of grapevine nursery blocks. Kress said CDFA collects about $140,000 annually in fees from grapevine nurseries for the program.

Regulations require that vine material certified under the program be tested for a specific list of viruses, however, GRBaV, officially recognized only since 2012, is not included in this list. There are also concerns that variants of leafroll viruses are not always being detected with current testing methods.

An ad hoc wine industry group met several times in 2014 to discuss nursery certification in relation to clean vine material. This led to a request for CDFA to review program regulations for possible revision. As stated in written comments submitted by the California Association of Winegrape Growers (CAWG) and signed by president John Aguirre, “Red Blotch made clear the Grapevine Registration and Certification Program is falling short in preventing the introduction and spread of new pathogens, and there are reasons to believe the program is performing unevenly in addressing currently listed viruses.”

Foundation Plant Services (FPS) at the University of California Davis (UCD) has been testing its Foundation block vine materials for GRBaV since 2013 and is now following Protocol 2010 standards for vine testing and propagation established under the National Clean Plant Network--protocols more stringent than the CDFA program. Under the Grapevine Registration and Certification Program, FPS is the source of Foundation block certified material made available to nurseries for propagation in increase blocks. Many California grapevine nurseries are voluntarily testing their vine material for GRBaV and have upgraded propagation and growing practices in response to industry concerns.

Issues Under Review

Potential issues to address in revising the regulations, in addition to GRBaV testing, include: the frequency and timing of testing and CDFA inspections at certified nurseries, nursery block location and eligibility requirements, the traceability of certified stock in the system, and standards for suspending/cancelling certification of vines and nursery blocks.

Under the program’s current regulations, vines in Foundation blocks and nursery increase blocks are required to be tested once every five years, and inspected by CDFA once a year during the growing season.

Consultant Dr. James Stamp of James Stamp Associates in Sebastopol commented: “It’s important that vines are tested and inspected at the right time of the year. You need to look at every vine in an increase block at the right time, and at both sides of the vine.” He also suggested vines be inspected for mealybugs and other potential pest vectors at appropriate times.

Another issue of concern in current regulations is the minimal requirement that states: “Certified nursery plantings shall be separated from non-certified grapevines by at least 10 feet where nursery soil has been treated to control nematodes. Certified nursery plantings shall be separated from non-certified grapevines by at least 20 feet where the soil has not been treated for nematodes.” John Crossland of Vineyard Professional Services, a vineyard management company in Paso Robles, said, “The current setbacks in the regulations are not nearly enough now that we know viruses can be vectored by mealybugs.” Daniel Bosch, viticulturist with Constellation Brands also advocated revising the distance standard for nurseries between certified and non-certified material. “Everyone in this room thinks that 10 feet is an unreasonable (and inadequate) standard,” Bosch said.

Meeting participants pointed out that revisions to the regulations must be justified based on current science and information. CDFA Pest Exclusion Branch chief Duane Schnabel, who conducted the meeting with Kress, explained: “The regulations have to be science-based, and the process also requires creating an economic analysis. A lot of information goes into the adoption of any new regulations.” Kress noted that current research evaluating the spread of GRBaV and leafroll virus by UCD plant pathology professor Neil McRoberts should provide data to assist in revising the distance standard between certified and non-certified vines.
John Duarte, president of Duarte Nursery based in Hughson, alluded to the challenges of the rulemaking process based on his participation in the last revision. He supported the idea of more regional meetings and said: “I encourage you to look more closely at who your technical advisors are in this process. Last time we didn’t have enough growers. Although I think we have more interest today than the last time, I’m still doubtful it will lead to the depth of changes that we need to have.”

CDFA Accepting Written Comments

Current program regulations are posted online for review at:

Growers, industry representatives and others may submit written comments at any time during the proceeding regarding program changes to Joshua Kress by e-mail at:
Written comments can also be sent by U.S. mail to: CDFA; Nursery, Seed and Cotton Program; 1220 N Street, Room 344; Sacramento, CA 95814.

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