Friend or Foe?
Vine Nutrition Effects
on Grape and
Wine Quality
WSU Viticulture & Enology Program
Markus Keller
Location, location…
•
•
•
•
•
•
Water and nutrients limit vine productivity
Climate variation and change
Amount and frequency of rainfall
Evaporation (temperature)
Spatial variation
Soil water/nutrient holding capacity
-
Soil texture (loam/sand)
Rooting depth
Organic matter
pH
• Vine age/size
Ground rules
2 - 6 lbs N/ton
WATER
NUTRIENTS
INTERACTION
Nutrient availability and uptake
• Nutrients concentrated in surface soil
• Availability linked to soil water
• Large spatial/temporal variation
 Roots grow in nutrient-rich zones
• Different nutrients in different locations
(leaching: NO3- >> K+ >> H2PO4-)
 Shallow roots: immobile nutrients
 Deep roots: mobile nutrients
• Active uptake  Concentration
• Transpiration   Uptake 
Nitrogen: What is it?
Chemical component of:
• Nucleic acids  DNA  Genes
• Amino acids  Proteins  Enzymes
• Chlorophyll  Light interception
• Hormones  Communication
• Secondary metabolites  Color, flavor
Nitrogen uptake and processing
• N2 in atmosphere (80%) useless for grapevines
• Mostly nitrate (NO3-) dissolved in soil water
• Soil water [NO3-] << Tissue [NO3-]
• Active uptake via H+-ATP pump
and H+/NO3- cotransport
• Uptake requires B (for ATP pump)
• Assimilation requires Mg2+, Mn2+ or Co2+
(as GS cofactors) and carbohydrates
 Expensive!
• Transport (xylem), storage (vacuole),
or assimilation  Amino acids  Proteins
H+
NO3-
N uptake and assimilation
LEAVES and FRUIT
NO3-
NH4+
Amino acids
Proteins
XYLEM
PHLOEM
NO3Amino acids
Sucrose
Amino acids
ROOTS
NO3-
NH4+
NO3-
NH4+
Amino acids
SOIL SOLUTION
Proteins
(m M)
OrganicxylemN
(m M)
InorganicxylemN
Roots pass surplus on to shoots
8
6
4
2
0
0
n
oN
1
0
0kgN
/h
a
2
4
6
8
T
o
ta
lx
y
le
m
N
(m
M
)
1
.5
n
oN
1
0
0kgN
/h
a
1
.0
0
.5
0
.0
0
2
4
6
T
o
talxylem
N
(m
M
)
8
Growth and nutrient status
• Growth drives nutrient uptake
• Insufficient nutrient supply
 growth  Vine N demand
Bloom
Soil N supply
• Water deficit  mass flow  + mineralization

 nutrient availability 
• Water deficit  growth   nutrient demand 
• Nutrient deficiency  - cell division 
Veraison ratio 
- root:shoot
- leaf starch 
- photosynthesis 
Budbreak
- root transport system 
Harvest
- reserve remobilization
Dormancy
Leaf fall
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
N Deficit
α
α
• Root growth 
 Drought susceptibility 
• Shoot growth 
• Photosynthesis 
 Energy overload
 Chlorophyll 
 Carbohydrates 
 Anthocyanins 
• Leaf senescence
 Nutrient recycling
Photosynthesis ( µmol CO 2/m 2s)
Photosynthesis
17
15
13
11
no N
100 kg N/ha
r = 0.80, p < 0.001
9
7
0
2
4
6
8
Total xylem N (mM)
Chlorophyll (mg/dm 2)
2.0
1.8
1.6
1.4
1.2
no N
100 kg N/ha
r = 0.80, p < 0.001
1.0
0.8
7
9
11
13
15
Photosynthesis (µmol CO 2/m2s)
17
K Deficit
•
•
•
•
Root growth () (K  cell expansion)
Shoot growth 
Photosynthesis 
Sugar export (phloem flow) 
 Ripening, reserves 
• Berry ‘shrivel’ (?)
• Xylem sap flow 
• Leaf senescence
 Nutrient recycling
P Deficit
• Root growth  (shallow),  (deep)
 Drought susceptibility 
• Mycorrhiza  P supply 
• Shoot growth  (laterals)
 Carbohydrates 
• Photosynthesis 
 Energy overload
 Anthocyanins 
• Mg transport in xylem 
 Mg deficiency symptoms
• Leaf senescence
 Nutrient recycling
23/09
1/10
8/10
15/10
22/10
29/10
5/11
12/11
19/11
26/11
23/09
1/10
8/10
15/10
22/10
29/10
5/11
12/11
19/11
26/11
140
23/09
1/10
8/10
15/10
22/10
29/10
5/11
12/11
19/11
26/11
(cm)
Shoot length
Shoot Length
(cm)
160
Complete
Slashed
Partial
Partial
Bare
Bare
Evaporation
120
100
80
60
40
20
0
Season 2002/03
Season 2003/04
Season 2004/05
Wagga Wagga
Use but beware of competition!
Stress and yield
• Vegetative growth vs. reproductive growth
• Time of nutrient deficit important
-
Budbreak – bloom
Bloom – fruit set
Cell division – cell expansion
Pre-veraison – post-veraison
 The later a stress occurs, the smaller its effect on yield
Early stress  Poor fruit set
N deficit?
50
Fruit set (%)
40
30
20
no N
100 kg N/ha
r = 0.58, p < 0.001
10
0
0
2
4
6
8
Total xylem N (mM)
Yes
No
• N, K, P, Ca, Fe, B, Zn, Cu, Mo,…, and salinity
• Often ‘hens & chicks’ (especially Zn, Mo, B)
• Nutrient stress also exacerbates water stress
How much N to apply?
2
4
1
0
0
%
S
u
n
lig
h
t
N
1
N
5
N
1
0
2
0
%
S
u
n
lig
h
t
N
1
m
e
a
n=2
0
.4
N
5
N
1
0
2
%
S
u
n
lig
h
t
N
1
N
5
N
1
0
(°Brix)
2
2
…it depends!
Solublesolids
2
0
1
8
1
6
5
0
m
e
a
n=2
9
8
1
5
0
2
5
0
3
5
0
Y
ie
ld
(g
/vin
e
)
4
5
0
5
5
0
N and fruit quality
• RDN (Regulated Deficit Nutrition):
 Berry size  (unless fruit set )
 Sugar (-)
 Malate  (less production)
 Tartrate (?)
 K+ 
 pH  (?)
 Amino acids (arginine!) 
 Phenolics (anthocyanins, flavonols...) 
 Flavors (-)
• Post-veraison berries remain responsive to N
N: Moderation is a virtue
28
Soluble solids (°Brix)
Soluble solids (°Brix)
20
19
18
17
16
15
no N
100 kg N/ha
27
26
25
24
23
r = -0.65***
14
22
2
4
6
8 10 12 14 16 18 20 22 24 26 28 30
Yield (t/ha)
Hot
Warm
Ambient
Cool
0
5
r = -0.47***
10
15
20
25
Growing tips/shoot at veraison
• More N  Higher yield
• More N  More lateral shoot growth, denser canopy
• Growing shoot tips compete with fruit  Delayed ripening
• N suppresses secondary metabolism (phenolics)
• N (and S) enhances volatile thiol precursor production
How to get poor color
Increasing N at bloom
N1
50
N5
N10
30
100%
20
10
0
50
40
30
20%
20
10
0
50
Delphinidin-3-glc
Cyanidin-3-glc
Petunidin-3-glc
Peonidin-3-glc
Malvidin-3-glc
40
30
20
2%
10
0
0
2
4
6
8
0
2
4
6
8
0
2
4
6
8
Weeks
Weeksafter
afterveraison
veraison
Worst case: High bloom-N + clouds during ripening
Decreasing
lightat
atveraison
veraison
Decreasing light
Anthocyanins (mg/g skin fw)
40
Going from bad to worse
(mg/L)
2
0
0
1
5
0
S
T
/n
oN
R
T
/n
oN
S
T
/9
0kgN
/h
a
R
T
/9
0kgN
/h
a
Totalanthocyanins
1
0
0
5
0
0
D
a
y0
D
a
y4
A
fte
rp
re
ss A
fte
rco
ldst.
D
a
y2
D
a
y6
A
fte
rM
L
F
Not possible to solve high-N problems with hedging
Exposure: Too much of a good thing?
Low N
Morning sun
High N
Afternoon sun
N suppresses flavonol production
Nutrition and deficit irrigation
(mg/L)
acids(mg/L)
amino
Juice
ug/mL
acids
Juice amino
350
300
Arginine-N
Proline-N
250
200
150
100
50
0
N40+0 N20+20 N0+40 N40+0 N20+20 N0+40 N40+0 N20+20 N0+40
STD
PRD
RDI
Standard
PRD
RDI
• Food for yeast: More N needed with water deficit
• Post-harvest N only with long post-harvest period
• Veraison N as good as bloom N for YAN
The Whites vs. the Reds
• Berry size and sun exposure less important for white
grapes (phenolics  astringency, bitterness!)
• Moderate N supply maximizes aroma potential
 Precursors of volatile thiols (mercaptans)
 ‘Blackcurrant’, ‘passion fruit’, ‘grapefruit’, (‘skunk’!)
• Low N  Low YAN (<150 mg/L)  Sluggish/stuck
fermentation  H2S (‘rotten eggs’!)
• More N may delay ripening
 Acid/flavor retention (advantage in hot seasons)
High N  Disease susceptibility
1.5
Soil N 1.0
0 g/vine
3 g/vine
8
50
0
Powdery mildew severity
(lesions/leaf)
Berries per cluster
100
0.5
6
0 4
0.2
1
2
0.0
Soil N (g/vine)
2
0
Chardonnay
Cabernet S.
Berry weight (g)
Botrytized
Healthy
Botrytis: What is the problem?
• Botrytis destroys berry cell integrity (membrane rupture)
 Mixing of cell components
• Botrytis secretes laccase = ‘nasty’ form of PPO
(stable at low pH, high temperature (>120ºF), ethanol)
 Oxidizes phenolics
(hydroxycinnamates, anthocyanins, tannins)
• Oxidation products (quinones) oxidize other compounds
(ascorbate, SO2)
• Worse in grapes with high hydroxycinnamate and low
glutathione (S transport & storage form) contents
 Control Botrytis, avoid mechanical damage, N and S
deficiency or excess, (late) overexposure!
K: The pH conundrum
3.9
3.8
Merlot (r = 0.32*)
Syrah (r = 0.79***)
Chardonnay (r = 0.73***)
Juice pH
3.7
3.6
3.5
3.4
3.3
3.2
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
Juice K+ (g/L)
• Juice and wine pH is sensitive to K
• Juice pH is not very responsive to soil K ( More malate)
• High soil pH may lead to lower juice pH ( Ca)
When to apply nutrients?
Lateral shoots
Primary shoots
Roots
Fruit
Phase 2
Growth
Phase 1
Bloom
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Growing season
Sep
Oct
Nov
The good news: It’s in the book!
www.amazon.com/Science-Grapevines-Anatomy-Physiology/dp/012374881X