The Crush - February 2020 - 2

[ FEATURE STORY ]
Research by Dr. Steven Lindow of the University of California,
Berkeley on the endophytic bacterium Paraburkholderia
phytofirmans shows great promise as a biological control for
PD through its ability to colonize in grapevine xylem tissue and
act like a vaccine to prevent the blockage of xylem tissue that
occurs when PD infects and spreads within a grapevine. Lindow
plans to do commercial scale tests over the next two years with
vineyard applications of this bacterium as a foliar spray with a
surfactant.
PD/GWSS Board research has evaluated chemical treatments
and led to the establishment of effective treatment protocols
for GWSS infestations and for managing GWSS insecticide
resistance. Research has provided biological control strategies
that include a program to breed and release parasitic wasps to
reduce GWSS populations.
The majority of assessment revenue funds research, but
assessments alone do not fund all of California's PD control
activities. The program is a partnership between industry
and government. By paying the assessment, the industry
demonstrates this program is important to support, and it
enables industry investments to be leveraged with federal and
state spending.
Overall program funding supports local activities by county
agricultural commissioner offices to maintain and monitor
GWSS traps, oversee required nursery stock treatments, conduct
nursery plant material shipment inspections at point-of-origin
nurseries in GWSS-infested counties, and conduct destination
inspections of nursery stock shipments in non-GWSS-infested
counties.
Federal funding through the U.S. Department of Agriculture
supports ongoing area-wide programs in California to control
the spread of established GWSS infestations in Riverside, Kern,
Tulare, Fresno and Madera counties. These combined efforts
effectively "hold the line" on GWSS in southern regions to
prevent its spread north to other winegrape regions. Industry
representatives who monitor federal budget negotiations believe
that without the grower assessment as a demonstration of
industry commitment, federal funding would not continue.
RESEARCH ON OTHER PESTS AND DISEASES
In 2009, legislation allowed the board to designate other serious
pests and diseases of winegrapes to receive assessment funds for
research and outreach, provided these efforts do not seriously
diminish PD-related efforts. The board designated the European
grapevine moth in 2010 and funded outreach that helped lead
to eventual eradication of this pest that threatened North Coast
vineyards. The board has since designated the following pests
and diseases of winegrapes for possible research and outreach:
grapevine red blotch disease, vine mealybug, brown marmorated
2 / FEBRUARY 2020

stink bug, grapevine leafroll disease, grapevine fanleaf disease,
mealybug pests of winegrapes, and spotted lanternfly.
Over the past 10 years, the board has allocated $6.3 million for
research and outreach on other designated pests and diseases
that are contributing to the following needs: improving
understanding of the transmission of and the effects of
grapevine viruses, exploring management practices for the
brown marmorated stink bug and mealybugs, and investigating
grape cultivars and rootstocks for resistance to vine mealybug.
The board has funded a multi-year project for grapevine virus
management for the Lodi Winegrape Commission (LWC) for
collaborative research and integrated outreach. This funding has
enabled three annual outreach meetings offered free for growers
statewide with presentations from international experts on virus
and mealybug management. The LWC will also produce a series
of written guides for growers covering virus and mealybug best
management practices.
VOTE BY MAIL, RETURN BALLOT IN 30 DAYS
The CDFA Marketing Branch oversees and conducts the
referendum. Eligible voters, expected to number more than 4,000,
include all entities that paid the assessment on grapes crushed
in 2019. Ballots are scheduled to be mailed to eligible growers/
voting entities in late March or early April. Voters will have
30 days to return ballots. Results of the vote are expected to be
announced in mid-June. At least 40 percent of eligible voters
must return ballots for the referendum to be valid. During the
last referendum in 2015, more than 80 percent of voters favored
continuation of the assessment.
The board sets the annual assessment rate, with a maximum of $3
per $1,000 of grape crush value. The maximum rate was assessed
only once, for the program's first year in 2001, as required by the
original legislation. The annual assessment rate has averaged
$1.39 per $1,000 of grape value, and the most recent rate for
2019 was $1 per $1,000 of grape value. Assessment funds have
provided revenue of nearly $70 million during the first 18 years
of collection.

MORE INFORMATION ON BOARD ACTIVITIES, RESEARCH
AND NEWS
>CDFA PD Control Program: www.cdfa.ca.gov/pdcp/
>PD/GWSS Board: www.pdgwss.net
http://www.cdfa.ca.gov/pdcp/ http://www.pdgwss.net
The Crush - February 2020

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