Some preliminary findings from our warm climate wine grape variety trial at the Kearney Agricultural Center, Parlier, CA.

1. Evaluation of 55 Winegrape Cultivars
for the San Joaquin Valley
Matthew Fidelibus
Extension Specialist
Department of Viticulture and Enology
UC Davis

2. Why evaluate new varieties?
• <10 wine grape varieties account for 80% of
varietal wines
• The most popular varieties were selected from
regions with climates cooler than the San
Joaquin Valley (SJV), and many struggle to
achieve optimal varietal character when
grown there

3. Challenges of unfamiliarity
• May be difficult to develop mass markets for
varietal wines with unrecognizable names
• Growers need viticultural information to make
informed planting decisions
• Winemakers need enological and sensory data to
determine how to make and market new wines

4. Opportunities with new varieties
Consumers
Interest & excitement from core consumers; ABC:
“Anything but Chardonnay”
Growers and wineries
Niche markets for products that are unique, distinctive, or
limited in supply
Source of wines with desirable blending characteristics
(flavor, color, tannin, acid)

5. Desired characteristics from new
varieties for warm climate regions
• Good yield potential
• Adaptable to mechanization
• Loose cluster architecture (low rot potential)
• High anthocyanin content (reds), and balanced fruit
composition
• Appealing flavor and wine quality attributes

6. Our Objectives:
 Evaluate winegrape cultivars
for characteristics suitable for
wine production in the San
Joaquin Valley, a hot climate
region.
 Deliver information to
nurseries, growers and
vintners that allow for well
informed and progressive
planting decisions.

7. Vineyard location and design
• Kearney Agricultural Center, Parlier, California.
• 1103P rootstock planted in 2008; scions grafted in
2009.
• 12 to 17 vines of each scion variety in 55 non-
replicated plots.
• Vines trained to bilateral cordons with 8 to 10 two-
bud spurs per meter cordon.
• Trellis consisted of steel stakes at each vine, a cordon
wire at 48“, and a 10” cross arm with two foliar catch
wires, “ above the cordon wire.

8. Cultural practices
• Begin watering after mid-day water potential
declined to about -1.3 bars
• Thereafter, vines received approximately 60%
ETc (monitored by Larry Williams).
• No fertilizers have been applied.
• Normal & ordinary pesticide applications were
made by research station staff.
• Vines were spur pruned in January 2012, and
pruning weights collected.

9. Data collected
• Yield, yield components, simple fruit
chemistry, & rot incidence were determined at
harvest (~22 Brix for whites, ~24 Brix for reds)
from 4 vines per plot.
• Fruit from 25-30 different varieties were
selected by Constellation for small lot wines.
• Pruning weights were collected in January,
2012.

10. Yield and harvest date of reds or whites

11. Yield and cluster weight

12. Yield vs number of clusters per vine

13. Berries per cluster and cluster weight
Cluster weight (kg)
0.0 0.2 0.4 0.6 0.8
Berriespercluster(no.)
0
100
200
300
400
500
red cultivars
white cultivars

14. Rot incidence and harvest date
Harvest, Day of Year
220 240 260 280 300 320
Rotincidence(%affectedclusters)
0
20
40
60
80
100
red cultivars
white cultivars

15. Some Promising Varieties
Bonarda, Fiano, Pinotage, Petit Manseng,
Segalin, Sagrantino
Not a complete list—others with good traits too

16. Poor performers
Rotters: Albillo Mayor, Albillo Real, Bianchetta Trevigiana,
Garnacha Tinta, Juan Garcia, Rousanne
Excessively late ripening: Forastera, Mourisco da
Samente, Ribolla Gialla, Rondinella

17. Variety and
clone
Reason for selection
Charbono 4, 5,
6, 7
Charbono is a synonym for Bonarda, a variety currently in the trial. Fruit
from the Bonarda vines in the trial has produced excellent wine, but the
yields are marginal and it has had excessive rot in one of two years.
Thus, we would like to determine if some of these faults could be
remedied by selecting different clones.
Saint Emilion Saint Emilion is a synonym of Trebbiano Toscano. Trebbiano Toscano in
the trial has proven to be a neutral flavored white wine grape with very
high yield potential, but also a high rot potential. We wish to evaluate
Saint Emilion to see if its rot potential is lower.
Triplett 30-47 ‘30-47’is a cross between Ruby Cabernet and Calzin. This variety was
recently selected from Triplett’s germplasm by Christensen due to its
productivity and high quality.
Teroldego 3, 4 Teroldego is a black wine grape from northern Italy. It is of interest due to
its reputation for producing deeply colored wines, a characteristic that
would be valuable in the San Joaquin Valley.
New varieties added in 2013

18. Other data and observations:
Cluster pictures from every
variety: http://www.flickr.com/photos/viticulture/
Annual reports: http://www.avf.org/
National grape registry: http://ngr.ucdavis.edu/
Power point presentations: http://www.slideshare.net/viticulture

20. Acknowledgements
• Jim Wolpert & Larry Williams, UC Davis
• American Vineyard Foundation
• Oren Kaye, Jim Orvis, & Dan
Bosch, Constellation Brands
• Stephen Vasquez and Glenn McGourty, UCCE
• Deborah Golino, Foundation Plant Services