The Crush October 2022 - 2

" Commercializing a new species takes time, money, and
effort. We felt that the best way to shorten that timeframe
was to create a farmer-led cooperative that would
purchase and install the grass with Vitidore acting as
a technical advisor, and enable coop members to get
a price discount. " The cooperative includes owners of
vineyards and nut and fruit orchards with potential to
plant 20,000 acres.
Trials have been coordinated by Vitidore co-founder
and president Dr. Alyssa DeVincentis who says Oakville
bluegrass has characteristics highly suited to vineyards
in Mediterranean climates. Its seasonal growth cycle
complements grapevines with an opposite growth cycle
related to its response to 12 hours of daylight. Its annual
growth begins after the first Fall rains and it remains
green through a grapevine's winter dormancy. The grass
begins dormancy in early spring so it will not compete
for soil moisture with grapevines as they begin spring
Other benefits include: it grows no taller than 6 inches,
so mowing is not required more than once a season; it
can form a dense mat over time to prevent weed growth,
reduce weed competition, and reduce herbicide use; it
produces biomass; and it can save labor and resource
inputs as a perennial grass being viable up to 10+ years.
DeVincentis observed, " It must be used in a no-till
system, which serves to reduce soil carbon and water
losses, and it's a tool that allows farmers to implement
no-till farming. "
Oakville bluegrass has been planted in vineyard and
orchard trials in California, Washington and Oregon
on more than 350 farm acres. California trials have
been conducted at more than 50 sites, coinciding with
drought over the past three years, that include vineyards
in Fresno, Lake, Sonoma, Napa, Monterey, San Luis
Obispo and Santa Barbara Counties. Oakville bluegrass
is currently part of a 5-year trial by the USDA Natural
Resources Conservation Service Lockeford Plant Materials
Center (San Joaquin County) to evaluate conservation
cover crop species for Central Valley vineyards and
Trials by UCD researchers at Oakville Station in Napa
Valley and in a Fresno County vineyard compared
six different cover crop and tillage management
combinations including Oakville bluegrass. Based on
trial results after the 2021 growing season, researchers
concluded that the use of cover crops under no-till
systems may be implemented in irrigated vineyards in the
San Joaquin Valley with no effect on grape productivity
but with improved grapevine water use. Economic
analysis from the UCD trials related to cultural costs
for vineyard management indicated transitioning from
tillage with resident vegetation or annual grass cover to
perennial grass/no-till in Napa can save from 3% to 6% in
Page 2 | October 2022
annual cultural costs, and in Fresno, can save from 9% to
16% in annual cultural costs resulting from reduced labor,
equipment use and fuel for tilling, mowing and other
Viticulture consultant and soil scientist Paul Skinner of
Vineyard Investigations began small-scale field trials
with Oakville bluegrass at his vineyard in St. Helena in
2020. Skinner is an advisor with Vitidore evaluating the
cover crop's affect on soil temperature, water infiltration,
root system biomass, and soil water holding capacity.
Skinner said, " With climate change, soil temperatures
are warming, and this may be one factor that speeds
up a vine's seasonal growing cycle. " He observed that
temperatures in tilled soils are usually warmer, so if soils
are staying cooler under cover crops in no-till systems
they can help mitigate the impacts of climate change and
potentially reduce evapotranspiration (ET) in vineyards
during the growing season. More information: www. and
* UC Agriculture and Natural Resources Publication
3338: Cover Cropping in Vineyards: A Growers
* UC Sustainable Agriculture Research and Education
Program Cover Crops Database. (Searchable
database of 40 common species)
* USDA Natural Resources Conservation Service:
Common Cover Crops for California
* Vineyard conversion to no-till and planting cover
crops may qualify California growers for grants under
California Department of Food and Agriculture's
(CDFA) Healthy Soils Program.
Fall cover crops/native cover re-emerge after recent rains.
Photo: Ted Rieger

The Crush October 2022

Table of Contents for the Digital Edition of The Crush October 2022

The Crush October 2022 - 1
The Crush October 2022 - 2
The Crush October 2022 - 3
The Crush October 2022 - 4
The Crush October 2022 - 5
The Crush October 2022 - 6
The Crush October 2022 - 7
The Crush October 2022 - 8
The Crush October 2022 - 9
The Crush October 2022 - 10