Vine grape potential byvanleeuwen
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Transcript of Vine grape potential byvanleeuwen
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
FACTORS DETERMING GRAPE POTENTIAL AND THEIR CONTROL
Professor Cornelis van Leeuwen
ENITA Bordeaux Agricultural
University
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
Plan
• Definition of grape potential
• Terroir: effects of climate, soil and grapevine variety
• Role of vine water status
• Examples of grape potential management in variousconditions of soil and climate
• Factors determing grape potential :
– Absence of grape diseases
– Vine vigor
– Berry weight
– Leaf / fruit weight ratio
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
How can grape potential be defined?
• A grape with a high enological potential :
– Is healthy
– Contains an optimum amount of sugar (variable depending on the type of wine)
– Contains an optimum acidity (variable dependingon the type of wine)
– Presents a good ability to ferment
• Ideal grape composition is highly variable dependingon wine type and color
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
Grape potential for the production of high
quality red wine
+ Small berries
+ High phenolic content in the skins (tannins, anthocyanin)
+ Phenolic ripeness
+ Ripe pips
- Vegetatif aromas under the perception treshold
- Low malic acid content
+ Varietal aromas
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
Grape potential for the production of high
quality white wine
+ Optimum acidity (variable depending on climatic zone)
- Low phenolic content in the skins
- Vegetatif aromas under the perception treshold
+ Fruity aromas
+ High glutathione content
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
High potential grapes are healthy
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
It is not possible to make good wines with
disease affected grapes
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
Effects of vine vigor on grapepotential
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
Vine vigor can be highlyvariable from one plot to
another
Merlot / 420A, plantation 1984-86, densité 4348 (AOC Buzet)
Medium to high vigor Medium to low vigor Very low vigor
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
How can vine vigor be estimated?
• Individual vigor of a vine
– Number and diameter of shoots
– Secondary leaf area / primary leaf area ratio
• Vigor of a plot of vines
– Pruning weight (kg/ha)
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
Excessive vigor
• Delays shoot growth cessation
– Competition for carbohydrates between grapesand shoots
• Increases berry weight
• Great development of laterals and suckers
– Competition apex / grapes
– Dense canopy
– Negative canopy micro climate implications:
→ temperature (lower malic acid degradation)
→ low light (less anthocyanin, more IBMP)
→ humidity (diseases)
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
Which parameters determinevine vigor ?
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
Effect of environmental ressources on vine vigor
• Soil (especially soil depth)
– Mineral elements (N, K, pH…)
– water (water holding capacity)
• Climate (effect on photosynthesis)
– temperature
– light
– water (rainfall and ETo)
(in : Zufferey, 2000)
Leaf temperature (°C)
Apparent photosynthesis
(µmol CO2 . m-² . s-1
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
Effect of plant material on vine vigor
• Rootstock
– Highly dominant effect
1 2 3 4 5
RipariaGloire de Montpellier
101-14 Mgt (-) ; 3309 C ;
420 A ; 161-49 C
Gravesac(-) ; 41 B ; Fercal
SO 4 ; 110 R
1103 P ; 5 BB ; 140 Ru ;
99 R
• Grapevine variety
– difficult to use
• Clone
– interesting aspect, insufficiently used
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
Effect of training system on vine vigor
• Training system determines exposedleaf area– Light interception
– Crop evapo-transpiration(ETC)
• Wich parametersdetermine exposed leafarea ?– Foliage height
– Density and particularlyrow spacing
40
45
50
55
60
65
70
75
80
1 1.2 1.4 1.6 1.8 2 2.2
Row spacing (m)
% i
nte
rce
pte
dra
dia
tio
n
h = 1.2m
h = 1m
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
Effect of berry weight on grapepotential
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
Relationship berry weight / grape potential
• Small berries containhigher sugar levels
• Small berries have higher concentrations in phenolics
y = -2,7084x + 113,09
R2 = 0,7157
40
45
50
55
60
65
70
18 19 20 21 22 23
°Brix
We
igh
t o
f 5
0 b
err
ies
(g
)
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
Which parameters determine berry weight?
• Genetic potential(grapevine variety, clone)
• Number of seeds
• Vine water status
• Vine nitrogen status
y = -0,2167x - 3,5687
R = -0,83
1,00
1,20
1,40
1,60
1,80
2,00
-25 -24 -23 -22 -21
Carbon isotope discrimination (deltaC13)
Berry weight (g)
Measured on grape sugar at ripeness
(in : Trégoat et al., 2003)
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
Effect of leaf area / fruit weightratio on grape potential
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
Which parameters determine leaf area / fruit weight ratio?
• Leaf area → limited by– Training system
– water ressources
– nitrogen ressources
• Fruit load– Fertility (cultivar, vigor)
– Number of budds / ha
– Number of berries / cluster
– Berry weight
(in : Huglin, 1958)
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
The terroir effect on grapepotential
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
• Environmental factors– Soil (type, depth)
– Climate (temperatures, rainfall, sunshine hours)
– Topography (altitude, slope, exposition)
• Biological factors– Grapevine variety
– Rootstock
– Vine age
• Human factors– Viticultural and enological practices
– Historical factors
– Economical factors
The « terroir » effect combines manyfactors
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
• It is not possible to define the ideal climate for
vine growing
• Great wines are produced on various soil
types
• Terroir can be defined as « an ecosystem,
managed by man, in which the vine interacts
with environmental factors (soil, climate) »
All these factors interact
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
• Climate, soil and grapevine variety playa major role in the terroir effect
• What is the hierarchy between thesethree factors?
Hierarchy of factors in theterroir effect
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
Experimental set-up
• Three red grapevine varieties: Cabernet-Sauvignon, Cabernet franc and Merlot
• Planted on three soils: Sand, Gravel and heavy Clay
• Where studied during eight vintages (variations in climate)
• 37 variables were registered
• 3 factor analyses of variance were carried out to compare the role of climate, soil and cultivar in theterroir effect
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
The soils
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
Eight vintages with specific climatic conditions
1996: Temperatures and rainfall in Saint-Emilion;
comparison with mean values
0
20
40
60
80
100
120
140
160
180
200
April May June July August September
Ra
infa
ll (
mm
)
0
5
10
15
20
25
Te
mp
era
ture
s (
°C)
1997
0
20
40
60
80
100
120
140
160
180
200
April May June July August September
Ra
infa
ll (
mm
)
0
5
10
15
20
25
Te
mp
era
ture
s (
°C)
1998
0
20
40
60
80
100
120
140
160
180
200
April May June July August September
Ra
infa
ll (
mm
)
0
5
10
15
20
25
Te
mp
era
ture
s (
°C)
1999
0
20
40
60
80
100
120
140
160
180
200
April May June July August September
Ra
infa
ll (
mm
)
0
5
10
15
20
25
Te
mp
era
ture
s (
°C)
Rainfall
Mean rainfall
Temperatures
Mean temperatures
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
2000: Temperatures and rainfall in Saint-Emilion;
comparison with mean values
0
20
40
60
80
100
120
140
160
180
200
April May June July August September
Ra
infa
ll (
mm
)
0
5
10
15
20
25
Te
mp
era
ture
s (
°C)
2001
0
20
40
60
80
100
120
140
160
180
200
April May June July August September
Ra
infa
ll (
mm
)
0
5
10
15
20
25
Te
mp
era
ture
s (
°C)
2002
0
20
40
60
80
100
120
140
160
180
200
April May June July August September
Ra
infa
ll (
mm
)
0
5
10
15
20
25
Te
mp
era
ture
s (
°C)
2003
0
20
40
60
80
100
120
140
160
180
200
April May June July August September
Ra
infa
ll (
mm
)
0
5
10
15
20
25
Te
mp
era
ture
s (
°C)
Rainfall
Mean rainfall
Temperatures
Mean temperatures
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
Water balance in the Bordeaux area for the vintages
1996, 1997, 1998 and 1999
-300
-250
-200
-150
-100
-50
0
1/4 1/5 31/5 30/6 30/7 29/8 28/9
Date
Wate
r b
ala
nc
e (
rain
fall -
ET
c)
in m
m
Water balance 1996
Water balance 1997
Water balance 1998
Water balance 1999
1997
1999
19961998
Water balance in the Bordeaux area for the vintages
2000, 2001, 2002 and 2003
-300
-250
-200
-150
-100
-50
0
1/4 1/5 31/5 30/6 30/7 29/8 28/9
Date
Wate
r b
ala
nce
(ra
infa
ll -
ET
c)
in m
m
Water balance 2000
Water balance 2001
Water balance 2002
Water balance 20032003
2000
2001
2002
1996: cool and relatively rainy1997: warm and rainy1998: temperate and dry1999: warm and relatively rainy2000: warm and dry2001: cool and relatively dry2002: cool and wet2003: hot and dry
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
Vine vigor
• One of the variables related to vine vigor is
the precociousness of shoot growth cessation
• Depending on the vintage and the soil type,
shoot growth cessation can be delayed to
over two monthes
• Delayed shoot growth cessation creates
competition between shoot growth and berry
ripening
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
Effect of climate, soil and cultivar onprecociousness of growth cessation
bb a abb a a
Precociousness of growth cessation: vintage effect
180
200
220
240
260
280
300
1996 1997 1998 1999 2000 2001 2002 2003
Vintage
Da
y o
f th
e y
ea
r
Precociousness of growth
cessation: soil effect
180
200
220
240
260
280
300
Gravel Sand Clay
Soil type
Da
y o
f th
e y
ea
r
Precociousness of growth
cessation: cultivar effect
180
200
220
240
260
280
300
Merlot Cabernet
franc
Cabernet-
Sauvignon
Grapevine variety
Da
y o
f th
e y
ea
r
b c f a g e d h
b a bb a a
Vintage effect: 75%of total variance
Cultivar effect: <1%of total variance
Soil effect: 15%of total variance
Effect of climate, soil and cultivar onprecociousness of growth cessation
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
Precociousness of phenological stages
• Depending on climate, soil and cultivar berries can reach ripeness more or less earlyin the season
• Too late ripening: lack of maturity, green andacid wines
• Too early ripening: wines lacking aroma and« finesse »
• Among phenological stages, veraison is mostappropriate to define objectively theprecociousness
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
Effect of climate, soil and cultivar onprecociousness of veraison
Precociousness of veraison: vintage effect
190
200
210
220
230
1996 1997 1998 1999 2000 2001 2002 2003
Vintage
Da
y o
f th
e y
ea
r
Precociousness of veraison:
soil effect
190
200
210
220
230
Gravel Sand Clay
Soil type
Da
y o
f th
e y
ea
r
Precociousness of veraison:
cultivar effect
190
200
210
220
230
Merlot Cabernet
franc
Cabernet-
Sauvignon
Grapevine variety
Da
y o
f th
e y
ea
r
b f c d da b e
b a b c a b
Vintage effect: 88%of total variance
Cultivar effect: 8%of total variance
Soil effect: 1%of total variance
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
Yield components
• Yield is determined by:– Number of vines per hectare (density)
– Number of shoots per vine
– Number of clusters per shoot (bud fertility)
– Number of berries per cluster
– Berry weight at harvest
• Among yield components, berry weight isalso directly related to grape potential:– Small berries have higher potential for making
quality red wines
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
Berry weight: vintage effect
1,0
1,1
1,2
1,3
1,4
1,5
1996 1997 1998 1999 2000 2001 2002 2003
Vintage
Be
rry w
eig
ht
(g)
Berry weight:
soil effect
1,0
1,1
1,2
1,3
1,4
1,5
Gravel Sand Clay
Soil type
Be
rry
we
igh
t (g
)
Berry weight: cultivar effect
1,0
1,1
1,2
1,3
1,4
1,5
Merlot Cabernet
franc
Cabernet-
Sauvignon
Grapevine variety
Be
rry
we
igh
t (g
)
Effect of climate, soil and cultivar onberry weight
Vintage effect: 25%of total variance
Cultivar effect: 19%of total variance
Soil effect: 32%of total variance
bc a b bc b ba
c
b a ba b b
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
Grape sugar
• Among variables indicating ripeness, grape sugar is most universally used
• However, it cannot be used alone to define grape potential
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
Grape sugar content at ripeness: vintage effect
190
195
200
205
210
215
220
225
1996 1997 1998 1999 2000 2001 2002 2003
Vintage
Su
ga
r (g
/L)
ccdc bababa
Grape sugar content at ripeness:
soil effect
190
195
200
205
210
215
220
225
Gravel Sand Clay
Soil type
Su
ga
r (g
/L)
Grape sugar content at
ripeness: cultivar effect
190195200205
210215220225
Merlot Cabernet
franc
Cabernet-
Sauvignon
Grapevine variety
Su
ga
r (g
/L)
Effect of climate, soil and cultivar ongrape sugar content
Vintage effect: 13%of total variance
Cultivar effect: 37%of total variance
Soil effect: 35%of total variance
b b
a a
b
c
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
Acidity
• Grape acidity can be expressed by:– Total acidity
– pH
– Tataric acid content
– Malic acid content
• Tartaric acid is the dominant organic acid in grapes, but its level shows little variations
• Malic acid is another important organic acid in grapes; its level is highly variable
• -> Variations in grape acidity are generally wellcorrelated with variations in grape malic acid content
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
Malic acid content at ripeness: vintage effect
0
10
20
30
40
50
60
1996 1997 1998 1999 2000 2001 2002 2003
Vintage
Ma
lic
ac
id (
me
q/L
)
Malic acid content at ripeness:
soil effect
0
10
20
30
40
50
60
Gravel Sand Clay
Soil type
Ma
lic
ac
id (
me
/L)
Malic acid content at ripeness:
cultivar effect
0
10
20
30
40
50
60
Merlot Cabernet
franc
Cabernet-
Sauvignon
Grapevine variety
Ma
lic
ac
id (
me
q/L
)
Effect of climate, soil and cultivar ongrape malic acid content
Vintage effect: 60%of total variance
Cultivar effect: 21%of total variance
Soil effect: 5%of total variance
a d e c c c c e
b a b c b a
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
Skin phenolic content
• Red wine quality is highly dependant on the abundance of grape skin phenolics
• Anthocyanin content is highly correlatedto tannin content
• Anthocyanin measurements are more reproductable than tannin measurements
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
Anthocyanin content at ripeness: vintage effect
0,4
0,6
0,8
1,0
1,2
1996 1997 1998 1999 2000 2001 2002 2003
Vintage
An
tho
cya
nin
(g
/kg
)
Anthocyanin content at ripeness:
soil effect
0,4
0,6
0,8
1,0
Gravel Sand Clay
Soil type
An
tho
cy
an
in (
g/k
g)
Anthocyanin content at
ripeness: cultivar effect
0,4
0,6
0,8
1,0
Merlot Cabernet
franc
Cabernet-
Sauvignon
Grapevine variety
An
tho
cy
an
in (
g/k
g)
Effect of climate, soil and cultivar ongrape anthocyanin content
Vintage effect: 31%of total variance
Cultivar effect: 4%of total variance
Soil effect: 39%of total variance
a d bc c ab bc c c
b c a b b a
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
Vine water status
• Climate and soil act on vine waterstatus
• Vine water status can be assessed by measuring leaf or stem water potential
• The more negative the values, the more the vine are subject to water deficit
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
Minimum pre-dawn leaf water potential: vintage effect
-0,6
-0,5
-0,4
-0,3
-0,2
-0,1
0,0
1996 1997 1998 1999 2000 2001 2002 2003
Vintage
Pre
-da
wn
le
af
wa
ter
po
ten
tia
l (M
pa
)
Minimum pre-dawn leaf water
potential: soil effect
-0,6
-0,5
-0,4
-0,3
-0,2
-0,1
0,0Gravel Sand Clay
Soil type
Pre
-da
wn
le
af
wa
ter
po
ten
tia
l (M
pa
)
Minimum pre-dawn leaf water
potential: cultivar effect
-0,6
-0,5
-0,4
-0,3
-0,2
-0,1
0,0M erlot Cabernet f ranc
Cabernet-
Sauvignon
Grapevine variety
Pre
-da
wn
le
af
wa
ter
po
ten
tia
l (M
pa
)
Vintage effect: 42%of total variance
Cultivar effect: 3%of total variance
Soil effect: 39%of total variance
Effect of climate, soil and cultivar onminimum pre-dawn leaf water potential
a bc f c e e b d
c a b
b b a
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
Correlation between shoot growth cessation and
minimum pre-dawn leaf water potential (Merlot,
Cabernet franc, Cabernet-Sauvignon, 1996-2003)
R2 = 0,4477
200
220
240
260
280
300
-1,0 -0,8 -0,6 -0,4 -0,2 0,0
Pre-dawn leaf water potential (MPa)
Sh
oo
t g
row
th
ce
ssati
on
(d
ay
of
the
year)
Correlation between shoot growth cessation and minimum pre-
dawn leaf water potential (Merlot, 1996-2003)
R2 = 0,3862
200
220
240
260
280
300
-1,0 -0,8 -0,6 -0,4 -0,2 0,0
Pre-dawn leaf water potential (MPa)
Sh
oo
t g
row
th c
essati
on
(day
of
the
ye
ar)
Correlation between shoot growth cessation and minimum
stem water potential (Merlot, 2000)
R2 = 0,6986
200
220
240
260
280
300
-2,0 -1,5 -1,0 -0,5 0,0
Stem water potential (MPa)
Sh
oo
t g
row
th c
essati
on
(day
of
the
ye
ar)
3 cultivars, 8 vintages
1 cultivar, 8 vintages
1 cultivar, 1 vintage
Correlation between vine water status andprecociousness of shoot growth cessation
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
Correlation between precociousness of veraison and
minimum pre-dawn leaf water potential (Merlot, Cabernet
franc, Cabernet-Sauvignon, 1996-2003)
190
200
210
220
230
-1,0 -0,8 -0,6 -0,4 -0,2 0,0
Pre-dawn leaf water potential (MPa)
Date
of
ve
rais
on
(d
ay
of
the
ye
ar)
Correlation between precociousness of veraison and minimum
pre-dawn leaf water potential (Merlot, 1996-2003)
190
200
210
220
230
-1,0 -0,8 -0,6 -0,4 -0,2 0,0
Pre-dawn leaf water potential (MPa)
Date
of
ve
rais
on
(d
ay
of
the
ye
ar)
Correlation between vine water status andprecociousness of veraison
3 cultivars, 8 vintages
1 cultivar, 8 vintages
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
Correlation between berry weight and minimum
pre-dawn leaf water potential (Merlot, Cabernet
franc, Cabernet-Sauvignon 1996-2003)
R2 = 0,2023
0,8
1,0
1,2
1,4
1,6
-1,0 -0,8 -0,6 -0,4 -0,2 0,0
Pre-dawn leaf water potential (MPa)
Be
rry
we
igh
t (g
)
Correlation between berry weight and minimum pre-dawn leaf
water potential (Merlot, 1996-2003)
R2 = 0,482
0,8
1,0
1,2
1,4
1,6
-1,0 -0,8 -0,6 -0,4 -0,2 0,0
Pre-dawn leaf water potential (MPa)
Be
rry
we
igh
t (g
)
Correlation between berry weight and minimum stem water
potential (Merlot, 2000)
R2 = 0,7578
1,0
1,2
1,4
1,6
1,8
2,0
-2,0 -1,5 -1,0 -0,5 0,0
Stem water potential (MPa)
Be
rry
we
igh
t (g
)
Correlation between vine water status andberry weight
3 cultivars, 8 vintages
1 cultivar, 8 vintages
1 cultivar, 1 vintage
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
Correlation between berry sugar content and minimum pre-
dawn leaf water potential (Merlot, Canbernet franc, Cabernet-
Sauvignon, 1996-2003)
R2 = 0,2997
180
190
200
210
220
230
240
250
-1,0 -0,8 -0,6 -0,4 -0,2 0,0
Pre-dawn leaf water potential (MPa)
Be
rry
su
gar
co
nte
nt
(g)
Correlation between berry sugar content and minimum pre-
dawn leaf water potential (Merlot, 1996-2003)
R2 = 0,5527
180
190
200
210
220
230
240
250
-1,0 -0,8 -0,6 -0,4 -0,2 0,0
Pre-dawn leaf water potential (MPa)
Be
rry
su
gar
co
nte
nt
(g)
Correlation between berry sugar content and minimum stem
water potential (Merlot, 2000)
R2 = 0,7132
210
220
230
240
250
260
270
-2,0 -1,5 -1,0 -0,5 0,0
Stem water potential (MPa)
Be
rry
su
gar
co
nte
nt
(g)
Correlation between vine water status andgrape sugar content
3 cultivars, 8 vintages
1 cultivar, 8 vintages
1 cultivar, 1 vintage
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
Correlation between berry malic acid content and minimum pre-
dawn leaf water potential (Merlot, Cabernet franc, Cabernet-
Sauvignon, 1996-2003)
R2 = 0,214
0
10
20
30
40
50
60
-1,0 -0,8 -0,6 -0,4 -0,2 0,0
Pre-dawn leaf water potential (MPa)
Malic a
cid
(m
eq
/L)
Correlation between berry malic acid content and minimum pre-
dawn leaf water potential (Merlot, 1996-2003)
R2 = 0,165
0
10
20
30
40
50
-1,0 -0,8 -0,6 -0,4 -0,2 0,0
Pre-dawn leaf water potential (MPa)
Malic a
cid
(m
eq
/L)
Correlation between berry malic acid content and minimum
stem water potential (Merlot, 2000)
R2 = 0,5248
0
10
20
30
40
50
-2,0 -1,5 -1,0 -0,5 0,0
Stem water potential (MPa)
Malic a
cid
(m
eq
/L)
Correlation between vine water status andgrape malic acid content
3 cultivars, 8 vintages
1 cultivar, 8 vintages
1 cultivar, 1 vintage
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
Correlation between berry tartrate content and minimum pre-
dawn leaf water potential (Merlot, Cabernet franc, Cabernet-
Sauvignon, 1996-2003)
50
60
70
80
90
100
-1,0 -0,8 -0,6 -0,4 -0,2 0,0
Pre-dawn leaf water potential (MPa)
Tart
rate
(m
eq
/L)
Correlation between berry tartrate content and minimum pre-
dawn leaf water potential (Merlot, 1996-2003)
50
60
70
80
90
100
-1,0 -0,8 -0,6 -0,4 -0,2 0,0
Pre-dawn leaf water potential (MPa)
Tart
rate
(m
eq
/L)
Correlation between vine water status andgrape tartaric acid content
3 cultivars, 8 vintages
1 cultivar, 8 vintages
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
Correlation between berry anthocyanin content and minimum
pre-dawn leaf water potential (Merlot, Cabernet-franc,
Cabernet-Sauvignon, 1996-2003)
R2 = 0,2246
0,60
0,70
0,80
0,90
1,00
1,10
1,20
-1,0 -0,8 -0,6 -0,4 -0,2 0,0
Pre-dawn leaf water potential (MPa)
An
tho
cya
nin
(g
/kg
)
Correlation between berry anthocyanin content and minimum
pre-dawn leaf water potential (Merlot, 1996-2003)
R2 = 0,4865
0,60
0,70
0,80
0,90
1,00
1,10
1,20
-1,0 -0,8 -0,6 -0,4 -0,2 0,0
Pre-dawn leaf water potential (MPa)
An
tho
cya
nin
(g
/kg
)
Correlation between berry anthocyanin content and minimum
stem water potential (Merlot, 2000)
R2 = 0,7799
1200
1400
1600
1800
2000
2200
2400
2600
-2,0 -1,5 -1,0 -0,5 0,0
Stem water potential (MPa)
An
tho
cya
nin
(g
/kg
)
Correlation between vine water status andgrape anthocyanin content
3 cultivars, 8 vintages
1 cultivar, 8 vintages
1 cultivar, 1 vintage
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
Among other factors , low nitrogensupply increases grape potential for
red wine making
2.42.0Malic acid (g/L)
5.44.7Total acidity (g tartrate/L)
4354Total Phenolics Index
12501490Anthocyanin (mg/L)
227247Grape sugar (g/L)
1.841.67Berry weight (g)
2.21.8Yield (kg/vine)
269260Shoot growth cessation (day of the year)
13463Assimilable must nitrogen (mg N/L)
525446N-tester values
High NLow N
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
However, nitrogen deficiencydecreases grape potential for white
wine making
120 (b)18 (a)Glutathione mg/L
0.21 (b)0.28 (a)Must total tannin content
14812 (b)3358 (a)P-3MH (ng eq/L)
2059 (b)760 (a)P-4MMPOH (ng eq/L)
715 (b)405 (a)P-4MMP (ng eq/L)
60 N0 N
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
Terroir effect
• On most of the variables, the effect of climate > soil > cultivar
• Terroir effect is largely mediated through vine waterstatus, which depends on climate (rainfall, ET0) andsoil (water holding capacity)
• Shoot growth and berry size are reduced in waterstressed vines
• Malic acid is reduced and anthocyanin is increased in water stressed vines
• Grape sugar content is optimum when water deficit ismild
• Precociousness of veraison and tartaric acid are not related to vine water status
• Low nitrogen supply increases red grape potentialand decreases white grape potential
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
Control of grape potential
• Examples in three differentclimatic zones
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
1 – Dry meditteranean climate, production of vin
red wine
• Warm and dry climate:
– Sufficient heatdegree days to obtain good ripeness
– Irregular rainfall
• Shallow soil
– Limited waterholding capacity
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
Consequences of climate and soil
• Sum degree days allows to bring most varieties to completeripeness
– Choice of late ripening varieties : Grenache, Syrah, Mourvèdre, petit Verdot
• Vines subject to water dificit
• A) When irrigation is not allowed or not possible
– Drought resistant rootstock (110 Richter)
– Limited leaf area
– Limited yield to maintail favorable leaf area / fruit weightratio
• B) When irrigation allowed and possible
- Apply deficit irrigation
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
Drought resitant rootstocks…
• …tend to be vigourous and so vines tend to developgreat leaf area in spring
• Leaf area has to be controlled to avoid water losses(in non irrigated vineyards)
– « Gobelet » training system is well adapted
– Average vine density (3500 à 4000 pieds / ha)
– Limit nitrogen supply to the vines
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
Production costs are low
• Little canopy management
• Few problems with vine diseases
• Low cost/ha (approximately 3000 € / ha) but
limited production (5 T/ha)
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
2 – Atlantic climate, red wine production
• Climate :
– Average sum of degree days
– Weak or moderatewater deficit
• Deep soil :
– Not limiting waterand mineral supplyto the vines
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
Consequences of climate and soil
• Choice of grapevine variety dependanton sum of degree days
• Low vigor rootstock
• Great leaf area
– Vine density > 5000 vines/ha
– Foliage height / row spacing = 0,8
– ->Exposed leaf area = 18 000 m2/ha
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
Yield should be limited
To limit yield (in order to respect a leafarea / fruit weight ratio of 1.5)
– Spur pruning
– Inter row grassing
– Bunch thinning
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
In this production system :
• Vine vigor tends to be excessif
• It should be controlled by
– The use of low vigor rootstocks
– Limitation of nitrogen fertilisation
– The use of inter row grassing
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
Effects on production costs
• Elaborated canopy management– desuckering
– Leaf removal
– Elimination of laterals
• Intensive pest control– Downy mildew
– Botrytis
– Powdery mildew
• High production costs (5000€/ha)
• Yield should be a function of exposed leafarea
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
3 – Cool climate viticulture, whitewine production
• Climate
– Low sum of degreedays
– Little or no limitation in vine water supply
• Soil
– Medium waterholding capacity andmineral supply
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
Consequences of climate and soil
• Coice of grapevine varieties limited by the sum of degree days (mainly white varieties)
• Low or medium vigor rootstock (depending on soillime content)
• Water supply allows great leaf area : > 5000 vines/ha possible
• When exposed leaf area / fruit weight ratio >1.5, a yield of 12T/ha is possible
• Limiting factor not desirable– Nitrogen fertilisation
– No inter row grassing
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
Pest controll is a major issue
• Look for cluster aeration
• When inter row spacing is limited, cumulated rowlength per hectare is optimized.
– Ideal density is 10 000 vines/ha
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
Effects on production costs
• Elaborated canopy management– desuckering
– Leaf removal
– Elimination of laterals
• Intensive pest control– Downy mildew
– Botrytis
– Powdery mildew
• High density
• High production costs (11 000 €/ha)
• Yield of 12T/ha possible
Van Leeuwen, 2004, Grapes, wine andenvironment, Roanoke (Virginia)
Conclusion
• In viticulture grape potential is a major issue
• Viticultural practices should be adapted to maximizegrape potential (role of limiting factor)
• Grape potential is highly dependant on environmentalfactors (soil, climate)
• Viticultural practices should be adapted to environmental conditions (climate and soil)
• Production cost should be controlled. However, theycan be highly variable depending on the viticulturalpractices (factor 1 à 4)