It seemed appropriate
this morning that I was driving through the Temecula Valley Wine
Country to hear a presentation on the vineyards. It was a
glorious morning, the vines have sprouted about a foot of verdant green
foliage, there was a gentle ground mist wending its way through the
hills and above the mist, two hot air balloons hovered silently. One of
those morning calling out for a good camera - which I didn't have.
Now imagine the
vineyards, the mist, the balloons didn't exist in Temecula. It almost
happened.
Was
it really only ten years ago that Wine
Spectator Magazine headlined an article 'The End for
California Wines'? In the late 90's, a new pest, the Glassy-Winged Sharpshooter (GWSS),
caused severe damage to grapevines in California, including wiping out
as much as 40% of some Temecula
Valley grape stock. The GW Sharpshooter spread a fatal
bacterium called Pierce's
Disease which had the potential to be as devastating to
California's grape crop as the phylloxera had back in the
1980's.
Phylloxera, an aphid like
creature fond of snacking on grape vine roots, has been under control
for the past several years but remains a background threat if
unmanaged. After a decade, they believe the GW Sharpshooter is also
largely contained but requires vigilant monitoring and ongoing
eradication attempts.
They meaning the team
that has been working on this issue for the past ten years and have
given our winegrowers a new lease on life. A unique partnership of
federal, state and local agriculture departments, industry and research
institutions is not only controlling the root louse, but is building a
foundation of new information on viticulture diseases in
general.
Long time residents
remember driving out Rancho California and seeing over 300 acres of
vineyard destroyed and plowed under to try to stay ahead of the bug.
Local grove manager Ben Drake
says "Research helped Temecula recover from our devastating losses. The
lessons learned and the partnerships formed here with other industries
are helping keep GWSS and PD from spreading to other parts of the state
until there is a permanent solution."
What
made our outbreak so virulent was that in the past the disease had
always transmitted itself via local insects. These local bugs would
acquire the bacterium from infected plants growing adjacent to the
vineyards. The infection was always transmitted early in the season and
could be controlled.
The GWSS brought a new
dimension to the game by being able to acquire the infection from
either an infected plant or an infected vine and then passing it on to
every vine it subsequently lunched on. Prior to GWSS, vine-to-vine transmission was virtually
unheard of. And with the infection period spread across
the whole growing season, the collapse of water-bearing capillaries was
deadly.
Mounting a massive
attack funded by federal and state government with significant
contributions by wineries statewide, the insect spread has been
contained and there are areas of Napa & Sonoma where the insect
has been eradicated. In monitored vineyards, and neighboring citrus
groves, where the GWSS winter, there has not been a single infestation
or major damage report for several years.
These folks are an
optimistic and focused group. They regaled us with tales of Green Zone
Barriers, biological control, and the fascinating life of a GWSS,
complete with photos and a specimen display. But it is a great example
of things going right, for a change. And of a lot of people
cooperating, including legislators, business owners, universities and
more. For more information on this chapter of California history, visit
Pierce's Disease
Control Program or PD/GWSS
Forum. It is an ongoing battle as is the need for funding to
continue.
I would feel a lot more
comfortable if these people were looking into the swine flu bug for us.