WSU Viticulture & Enology Program. Friend or Foe? Vine Nutrition Effects on Grape and Wine Quality

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1 WSU Viticulture & Enology Program Markus Keller Friend or Foe? Vine Nutrition Effects on Grape and Wine Quality

2 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

3 Ground rules 2-6 lbs N/ton WATER NUTRIENTS INTERACTION

4 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: NO - 3 >> K + >> H 2 PO 4- ) Shallow roots: immobile nutrients Deep roots: mobile nutrients Active uptake Concentration Transpiration Uptake

5 Nitrogen: What is it? Chemical component of: Nucleic acids DNA Genes Amino acids Proteins Enzymes Chlorophyll Light interception Hormones Communication Secondary metabolites Color, flavor

6 Nitrogen uptake and processing N 2 in atmosphere (80%) useless for grapevines Mostly nitrate (NO 3- ) dissolved in soil water Soil water [NO 3- ] << Tissue [NO 3- ] Active uptake via H + -ATP pump and H + /NO 3 - cotransport Uptake requires B (for ATP pump) Assimilation requires Mg 2+, Mn 2+ or Co 2+ (as GS cofactors) and carbohydrates Expensive! H + NO 3 - Transport (xylem), storage (vacuole), or assimilation Amino acids Proteins

7 N uptake and assimilation LEAVES and FRUIT NO 3 - NH 4 + Amino acids Proteins XYLEM NO 3 - Amino acids PHLOEM Sucrose Amino acids ROOTS NO 3 - NH 4 + Amino acids Proteins NO 3 - NH 4 + SOIL SOLUTION

8 Roots pass surplus on to shoots OrganicxylemN (m M) non 100kgN/ha Total xylemn(mm) InorganicxylemN (m M) non 100kgN/ha Total xylemn(mm)

9 Growth and nutrient status Growth drives nutrient uptake Insufficient nutrient supply growth Budbreak Dormancy Bloom - root:shoot Veraison ratio Vine N demand Soil N supply Water deficit mass flow + mineralization nutrient availability Water deficit growth nutrient demand Nutrient deficiency - cell division - leaf starch - photosynthesis - root transport system Harvest Leaf fall - reserve remobilization Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

10 N Deficit α α Root growth Drought susceptibility Shoot growth Photosynthesis Energy overload Chlorophyll Carbohydrates Anthocyanins Leaf senescence Nutrient recycling

11 Photosynthesis (µmol CO 2 /m 2 s) Chlorophyll (mg/dm 2 ) Total xylem N (mm) no N 100 kg N/ha r = 0.80, p < no N kg N/ha r = 0.80, p < Photosynthesis (µmol CO 2 /m 2 s) Photosynthesis

12 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

13 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

14 Evaporation Shoot Length (cm) Shoot length (cm) Complete Slashed Partial Bare Bare /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 23/09 1/10 8/10 15/10 22/10 29/10 5/11 12/11 19/11 26/11 Season 2002/03 Season 2003/04 Wagga Wagga Season 2004/05 Use but beware of competition!

15 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

16 Early stress Poor fruit set N deficit? 50 Fruit set (%) Yes Total xylem N (mm) no N 100 kg N/ha r = 0.58, p < 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

17 How much N to apply? Solublesolids ( Brix) it depends! mean= %Sunlight N1 N5 N10 20%Sunlight N1 N5 N10 2%Sunlight N1 N5 N10 mean= Yield(g/vine)

18 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

19 N: Moderation is a virtue Soluble solids ( Brix) no N 100 kg N/ha Yield (t/ha) r = -0.65*** Soluble solids ( Brix) Hot Warm Ambient Cool r = -0.47*** 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

20 How to get poor color Anthocyanins (mg/g skin fw) Increasing N at bloom N1 N5 N10 Delphinidin-3-glc Cyanidin-3-glc Petunidin-3-glc Peonidin-3-glc Malvidin-3-glc 100% 20% 2% Decreasing light at at veraison Weeks after after veraison veraison Worst case: High bloom-n + clouds during ripening

21 Going from bad to worse Total anthocyanins (mg/l) ST/noN RT/noN ST/90kgN/ha RT/90kgN/ha Day 0 Day 4 After press After coldst. Day 2 Day 6 After MLF Not possible to solve high-n problems with hedging

22 Exposure: Too much of a good thing? Low N Morning sun High N Afternoon sun N suppresses flavonol production

23 Juice amino ug/ml acids (mg/l) Nutrition and deficit irrigation 350 Arginine-N 300 Proline-N N40+0 N20+20 N0+40 N40+0 N20+20 N0+40 N40+0 N20+20 Standard STD PRD RDI N0+40 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

24 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 H 2 S ( rotten eggs!) More N may delay ripening Acid/flavor retention (advantage in hot seasons)

25 High N Disease susceptibility Berries per cluster Powdery mildew severity (lesions/leaf) Botrytized Healthy Soil N (g/vine) Soil N 0 g/vine 3 g/vine Berry weight (g) 0 Chardonnay Cabernet S.

26 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, SO 2 ) 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!

27 K: The ph conundrum Merlot (r = 0.32*) Syrah (r = 0.79***) Chardonnay (r = 0.73***) 3.7 Juice ph 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)

28 When to apply nutrients? Lateral shoots Primary shoots Fruit Roots Phase 2 Growth Phase 1 Bloom Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Growing season

29 The good news: It s in the book!