Vine grape potential byvanleeuwen

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  • 1. FACTORS DETERMING GRAPEPOTENTIAL AND THEIR CONTROL Professor Cornelis van Leeuwen ENITA Bordeaux Agricultural University Van Leeuwen, 2004, Grapes, wine and environment, Roanoke (Virginia)
  • 2. Plan• Definition of grape potential• Factors determing grape potential : – Absence of grape diseases – Vine vigor – Berry weight – Leaf / fruit weight ratio• Terroir: effects of climate, soil and grapevine variety• Role of vine water status• Examples of grape potential management in variousconditions of soil and climate Van Leeuwen, 2004, Grapes, wine and environment, Roanoke (Virginia)
  • 3. 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 depending on the type of wine) – Presents a good ability to ferment• Ideal grape composition is highly variable depending on wine type and color Van Leeuwen, 2004, Grapes, wine and environment, Roanoke (Virginia)
  • 4. Grape potential for the production of high quality red wine+ Small berries+ High phenolic content in the skins (tannins,anthocyanin)+ Phenolic ripeness+ Ripe pips+ Varietal aromas- Vegetatif aromas under the perception treshold- Low malic acid content 2004, Grapes, wine and Van Leeuwen, environment, Roanoke (Virginia)
  • 5. Grape potential for the production of high quality white wine+ Optimum acidity (variable depending on climatic zone)+ Fruity aromas+ High glutathione content- Vegetatif aromas under the perception treshold- Low phenolic content in the skins Van Leeuwen, 2004, Grapes, wine and environment, Roanoke (Virginia)
  • 6. High potential grapes are healthy Van Leeuwen, 2004, Grapes, wine and environment, Roanoke (Virginia)
  • 7. It is not possible to make good wines with disease affected grapes Van Leeuwen, 2004, Grapes, wine and environment, Roanoke (Virginia)
  • 8. Effects of vine vigor on grape potential Van Leeuwen, 2004, Grapes, wine and environment, Roanoke (Virginia)
  • 9. Vine vigor can be highly variable from one plot to anotherMedium to high vigor Medium to low vigor Very low vigor Merlot / 420A, plantation 1984-86, densité 4348 (AOC Buzet) Van Leeuwen, 2004, Grapes, wine and environment, Roanoke (Virginia)
  • 10. 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 and environment, Roanoke (Virginia)
  • 11. Excessive vigor• Delays shoot growth cessation – Competition for carbohydrates between grapes and shoots• 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)• Increases berry Van Leeuwen, 2004, Grapes, wine and weight environment, Roanoke (Virginia)
  • 12. Which parameters determine vine vigor ? Van Leeuwen, 2004, Grapes, wine and environment, Roanoke (Virginia)
  • 13. Effect of environmental ressources on vine vigorApparent photosynthesis (µmol CO2 . m-² . s-1 • Soil (especially soil depth) – Mineral elements (N, K, pH…) – water (water holding capacity) • Climate (effect on photosynthesis) – temperature – light – water (rainfall and ETo) Leaf temperature (°C) Van Leeuwen, 2004, Grapes, wine and (in : Zufferey, 2000) environment, Roanoke (Virginia)
  • 14. Effect of plant material on vine vigor • Rootstock – Highly dominant effect 1 2 3 4 5Riparia 101-14 Mgt Gravesac SO 4 ; 1103 P ;Gloire de (-) ; (-) ; 41 B ; 110 R 5 BB ;Montpellier 3309 C ; Fercal 140 Ru ; 420 A ; 161- 99 R 49 C • Grapevine variety – difficult to use • Clone – interesting aspect, Van Leeuwen, 2004, Grapes, wine and insufficiently used environment, Roanoke (Virginia)
  • 15. Effect of training system on vine vigor • Training system 80 determines exposed 75 h = 1.2m leaf area 70 h = 1m – Light interception – Crop evapo-transpiration% intercepted 65 radiation 60 (ETC) 55 • Wich parameters 50 determine exposed leaf 45 area ? 40 1 1.2 1.4 1.6 1.8 2 2.2 – Foliage height – Density and particularly Row spacing (m) row spacing Van Leeuwen, 2004, Grapes, wine and environment, Roanoke (Virginia)
  • 16. Effect of berry weight on grape potential Van Leeuwen, 2004, Grapes, wine and environment, Roanoke (Virginia)
  • 17. Relationship berry weight / grape potential 70 y = -2,7084x + 113,09 • Small berries containWeight of 50 berries (g) 2 65 R = 0,7157 higher sugar levels 60 55 • Small berries have 50 higher concentrations 45 in phenolics 40 18 19 20 21 22 23 °Brix Van Leeuwen, 2004, Grapes, wine and environment, Roanoke (Virginia)
  • 18. Which parameters determine berry weight? Berry weight (g) • Genetic potential 2,00 (grapevine variety, clone) 1,80 • Number of seeds 1,60 • Vine water status 1,40 • Vine nitrogen status y = -0,2167x - 3,5687 1,20 R = -0,83 1,00 -25 -24 -23 -22 -21 Carbon isotope discrimination (deltaC13) Measured on grape sugar at ripeness Van Leeuwen, 2004, Grapes, wine and(in : Trégoat et al., 2003) environment, Roanoke (Virginia)
  • 19. Effect of leaf area / fruit weight ratio on grape potential Van Leeuwen, 2004, Grapes, wine and environment, Roanoke (Virginia)
  • 20. Van Leeuwen, 2004, Grapes, wine and environment, Roanoke (Virginia)
  • 21. 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 and environment, Roanoke (Virginia)
  • 22. The terroir effect on grape potential Van Leeuwen, 2004, Grapes, wine and environment, Roanoke (Virginia)
  • 23. The « terroir » effect combines many factors• 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 Van Leeuwen, 2004, Grapes, wine and environment, Roanoke (Virginia)
  • 24. All these factors interact• 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) » Van Leeuwen, 2004, Grapes, wine and environment, Roanoke (Virginia)
  • 25. Hierarchy of factors in the terroir effect• Climate, soil and grapevine variety play a major role in the terroir effect• What is the hierarchy between these three factors? Van Leeuwen, 2004, Grapes, wine and environment, Roanoke (Virginia)
  • 26. 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 the terroir effect Van Leeuwen, 2004, Grapes, wine and environment, Roanoke (Virginia)
  • 27. The soilsVan Leeuwen, 2004, Grapes, wine and environment, Roanoke (Virginia)
  • 28. Eight vintages with specific climatic conditions 1996: Temperatures and rainfall in Saint-Emilion; 1997 comparison with mean values 200 25 200 25 180 180 160 20 160 20 140 Temperatures (°C) Temperatures (°C) 140 Rainfall (mm)Rainfall (mm) 120 15 120 15 100 100 80 10 80 10 60 60 40 5 40 5 20 20 0 0 0 0 April May June July August September April May June July August September 1998 1999 200 25 200 25 180 180 160 20 160 20 140 Temperatures (°C) Temperatures (°C) 140 Rainfall Rainfall (mm)Rainfall (mm) 120 15 120 Mean rainfall 15 100 Temperatures 100 Mean temperatures 80 10 80 10 60 60 40 5 40 5 20 20 0 0 0 0 April May June July Van Leeuwen, 2004, Grapes, wine and August September April May June July August September environment, Roanoke (Virginia)
  • 29. 2000: Temperatures and rainfall in Saint-Emilion; 2001 comparison with mean values 200 25 200 25 180 180 160 20 160 20 140 Temperatures (°C) Temperatures (°C) 140 Rainfall (mm)Rainfall (mm) 120 15 120 15 100 100 80 10 80 10 60 60 40 5 40 5 20 20 0 0 0 0 April May June July August September April May June July August September 2002 2003 200 25 200 25 180 180 160 20 160 20 Rainfall 140 140 Temperatures (°C) Temperatures (°C) Mean rainfall Rainfall (mm)Rainfall (mm) 120 15 120 Temperatures 15 100 100 Mean temperatures 80 10 80 10 60 60 40 5 40 5 20 20 0 0 0 0 April May June July August September April May June July August September Van Leeuwen, 2004, Grapes, wine and environment, Roanoke (Virginia)
  • 30. Water balance in the Bordeaux area for the vintages Water balance in the Bordeaux area for the vintages 1996, 1997, 1998 and 1999 2000, 2001, 2002 and 2003 Date Date 1/4 1/5 31/5 30/6 30/7 29/8 28/9 1/4 1/5 31/5 30/6 30/7 29/8 28/9 0 0 Water balance (rainfall - ETc) -50Water balance (rainfall - ETc) -50 1997 2002 -100 -100 1999 in m m in mm -150 -150 Water balance 1996 Water balance 2000 2001 -200 -200 Water balance 1997 Water balance 2001 -250 Water balance 1998 -250 Water balance 2002 1996 2003 Water balance 1999 1998 Water balance 2003 2000 -300 -300 1996: cool and relatively rainy 1997: warm and rainy 1998: temperate and dry 1999: warm and relatively rainy 2000: warm and dry 2001: cool and relatively dry 2002: cool and wet 2003: hot and dry Van Leeuwen, 2004, Grapes, wine and environment, Roanoke (Virginia)
  • 31. 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 and environment, Roanoke (Virginia)
  • 32. Effect of climate, soil and cultivar on precociousness of growth cessation Precociousness of growth cessation: vintage effect Effect of climate, soil and cultivar on 300 precociousness of growthe cessation b c f280 a g d h Vintage effect: 75% Day of the year 260 of total variance 240 220 200 180 bb 1996 1997 1998 1999 2000 2001 2002 2003 bb a a a a Vintage Precociousness of growth Precociousness of growth cessation: soil effect cessation: cultivar effect 300 300 b a b Day of the ye ar 280 280 Day of the ye arSoil effect: 15% 260 260 b a a Cultivar effect: <1%of total variance 240 240 of total variance 220 220 200 200 180 180 Merlot Cabernet Cabernet- Gravel Sand Clay franc Sauvignon Grapevine variety Soil type Van Leeuwen, 2004, Grapes, wine and environment, Roanoke (Virginia)
  • 33. Precociousness of phenological stages• Depending on climate, soil and cultivar berries can reach ripeness more or less early in the season• Too late ripening: lack of maturity, green and acid wines• Too early ripening: wines lacking aroma and « finesse »• Among phenological stages, veraison is most appropriate to define objectively the precociousness Van Leeuwen, 2004, Grapes, wine and environment, Roanoke (Virginia)
  • 34. Effect of climate, soil and cultivar on precociousness of veraison Precociousness of veraison: vintage effect 230 b f c d d a b e Vintage effect: 88% Day of the year 220 of total variance 210 200 190 1996 1997 1998 1999 2000 2001 2002 2003 Vintage Precociousness of veraison: Precociousness of veraison: soil effect cultivar effect 230 230Soil effect: 1% c a b Day of the ye ar b a b Cultivar effect: 8% Day of the ye ar 220 220of total variance of total variance 210 210 200 200 190 190 Merlot Cabernet Cabernet- Gravel Sand Clay franc Sauvignon Grapevine variety Van Leeuwen, 2004, Grapes, wine and Soil type environment, Roanoke (Virginia)
  • 35. 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 is also directly related to grape potential: – Small berries have higher potential for making quality red wines Van Leeuwen, 2004, Grapes, wine and environment, Roanoke (Virginia)
  • 36. Effect of climate, soil and cultivar on berry weight Berry weight: vintage effect 1,5 bc a b bc b b a c Berry weight (g) 1,4 Vintage effect: 25% 1,3 of total variance 1,2 1,1 1,0 1996 1997 1998 1999 2000 2001 2002 2003 Vintage Berry weight: Berry weight: cultivar effect soil effect 1,5 a b b Be rry w e ight (g) 1,5 1,4 b a b Be rry w e ight (g) 1,4 1,3Soil effect: 32% 1,3 Cultivar effect: 19% 1,2of total variance 1,2 of total variance 1,1 1,1 1,0 1,0 Merlot Cabernet Cabernet- Gravel Sand Clay franc Sauvignon Grapevine variety Soil type Van Leeuwen, 2004, Grapes, wine and environment, Roanoke (Virginia)
  • 37. 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 and environment, Roanoke (Virginia)
  • 38. Effect of climate, soil and cultivar on grape sugar content Grape sugar content at ripeness: vintage effect 225 c d c c a ab ab b 220 215 Vintage effect: 13% Sugar (g/L) 210 of total variance 205 200 195 190 1996 1997 1998 1999 2000 2001 2002 2003 Vintage Grape sugar content at ripeness: Grape sugar content at soil effect ripeness: cultivar effect a a 225 225 220 220 b Sugar (g/L)Soil effect: 35% 215 Sugar (g/L) 215 210 b b 210 Cultivar effect: 37%of total variance 205 c 205 200 of total variance 200 195 195 190 190 Merlot Cabernet Cabernet- Gravel Sand Clay franc Sauvignon Grapevine variety Soil type Van Leeuwen, 2004, Grapes, wine and environment, Roanoke (Virginia)
  • 39. 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 well correlated with variations in grape malic acid content Van Leeuwen, 2004, Grapes, wine and environment, Roanoke (Virginia)
  • 40. Effect of climate, soil and cultivar on grape malic acid content Malic acid content at ripeness: vintage effect 60 a d e c c c c e Malic acid (meq/L) 50 Vintage effect: 60% 40 of total variance 30 20 10 0 1996 1997 1998 1999 2000 2001 2002 2003 Vintage Malic acid content at ripeness: Malic acid content at ripeness: soil effect cultivar effect 60 60 M alic acid (m e q/L) M alic acid (m e /L) 50 50Soil effect: 5% b a b c b a 40 40 Cultivar effect: 21%of total variance 30 30 of total variance 20 20 10 10 0 0 Merlot Cabernet Cabernet- Gravel Sand Clay franc Sauvignon Grapevine variety Soil type Van Leeuwen, 2004, Grapes, wine and environment, Roanoke (Virginia)
  • 41. Skin phenolic content• Red wine quality is highly dependant on the abundance of grape skin phenolics• Anthocyanin content is highly correlated to tannin content• Anthocyanin measurements are more reproductable than tannin measurements Van Leeuwen, 2004, Grapes, wine and environment, Roanoke (Virginia)
  • 42. Effect of climate, soil and cultivar on grape anthocyanin content Anthocyanin content at ripeness: vintage effect 1,2 Anthocyanin (g/kg) 1,0 a d bc c ab bc c c Vintage effect: 31% of total variance 0,8 0,6 0,4 1996 1997 1998 1999 2000 2001 2002 2003 Vintage Anthocyanin content at ripeness: Anthocyanin content at soil effect ripeness: cultivar effect Anthocyanin (g/k g) Anthocyanin (g/k g) 1,0 b c a 1,0 b b aSoil effect: 39% Cultivar effect: 4% 0,8 0,8of total variance of total variance 0,6 0,6 0,4 0,4 Merlot Cabernet Cabernet- Gravel Sand Clay franc Sauvignon Grapevine variety Soil type Van Leeuwen, 2004, Grapes, wine and environment, Roanoke (Virginia)
  • 43. Vine water status• Climate and soil act on vine water status• 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 and environment, Roanoke (Virginia)
  • 44. Effect of climate, soil and cultivar on minimum pre-dawn leaf water potential Minimum pre-dawn leaf water potential: vintage effect 1996 1997 1998 1999 2000 2001 2002 2003 0,0 Vintage effect: 42% Pre-dawn leaf water -0,1 potential (Mpa) -0,2 of total variance -0,3 -0,4 -0,5 -0,6 a bc f c e e b d Vintage Minimum pre-dawn leaf water Minimum pre-dawn leaf water potential: soil effect potential: cultivar effect Cabernet- Gravel Sand Clay M erlot Cabernet franc Sauvignon 0,0 0,0Soil effect: 39% Pre -daw n le af w ate r Pre -daw n le af w ate r -0,1 -0,1 Cultivar effect: 3% pote ntial (M pa) pote ntial (M pa)of total variance -0,2 -0,2 of total variance -0,3 -0,3 -0,4 -0,4 -0,5 -0,5 b b a -0,6 c a b -0,6 Soil type Grapevine variety Van Leeuwen, 2004, Grapes, wine and environment, Roanoke (Virginia)
  • 45. Correlation between vine water status and precociousness of shoot growth cessation Correlation between shoot growth cessation and minimum pre-dawn leaf water potential (Merlot, Cabernet franc, Cabernet-Sauvignon, 1996-2003) 300 cessation (day of the 2 R = 0,4477 280 Shoot growth 260 3 cultivars, 8 vintages year) 240 220 200-1,0 -0,8 -0,6 -0,4 -0,2 0,0 Pre-dawn leaf water potential (MPa) Correlation between shoot growth cessation and minimum pre- dawn leaf water potential (Merlot, 1996-2003) 300 Shoot growth cessation R2 = 0,3862 (day of the year) 280 260 1 cultivar, 8 vintages 240 220 200 -1,0 -0,8 -0,6 -0,4 -0,2 0,0 Pre-dawn leaf water potential (MPa) Correlation between shoot growth cessation and minimum stem water potential (Merlot, 2000) 300 Shoot growth cessation 2 R = 0,6986 (day of the year) 280 260 1 cultivar, 1 vintage 240 220 200 -2,0 -1,5 -1,0 -0,5 0,0 Van Leeuwen, 2004, Grapes, wine and Stem water potential (MPa) environment, Roanoke (Virginia)
  • 46. Correlation between vine water status and precociousness of veraison Correlation between precociousness of veraison andminimum pre-dawn leaf water potential (Merlot, Cabernet franc, Cabernet-Sauvignon, 1996-2003) 230 3 cultivars, 8 vintages Date of veraison (day of the year) 220 210 200 190 -1,0 -0,8 -0,6 -0,4 -0,2 0,0 Pre-dawn leaf water potential (MPa) Correlation between precociousness of veraison and minimum pre-dawn leaf water potential (Merlot, 1996-2003) 230 Date of veraison (day of the year) 220 1 cultivar, 8 vintages 210 200 190 -1,0 -0,8 -0,6 -0,4 -0,2 0,0 Van Leeuwen, 2004, Grapes,Pre-dawn leaf water potential (MPa) wine and environment, Roanoke (Virginia)
  • 47. Correlation between vine water status and berry weight Correlation between berry weight and minimum pre-dawn leaf water potential (Merlot, Cabernet franc, Cabernet-Sauvignon 1996-2003) 1,6 3 cultivars, 8 vintages Berry weight (g) R2 = 0,2023 1,4 1,2 1,0 0,8-1,0 -0,8 -0,6 -0,4 -0,2 0,0 Pre-dawn leaf water potential (MPa) Correlation between berry weight and minimum pre-dawn leaf water potential (Merlot, 1996-2003) 1,6 R2 = 0,482 1 cultivar, 8 vintages Berry weight (g) 1,4 1,2 1,0 0,8 -1,0 -0,8 -0,6 -0,4 -0,2 0,0 Pre-dawn leaf water potential (MPa) Correlation between berry weight and minimum stem water potential (Merlot, 2000) 2,0 2 R = 0,7578 1,8 Berry weight (g) 1,6 1 cultivar, 1 vintage 1,4 1,2 1,0 -2,0 -1,5 -1,0 -0,5 0,0 Van Leeuwen, 2004, Grapes, wine and Stem water potential (MPa) environment, Roanoke (Virginia)
  • 48. Correlation between vine water status and grape sugar content Correlation between berry sugar content and minimum pre- dawn leaf water potential (Merlot, Canbernet franc, Cabernet- Sauvignon, 1996-2003) Berry sugar content (g) 2 250 R = 0,2997 240 230 220 3 cultivars, 8 vintages 210 200 190 180-1,0 -0,8 -0,6 -0,4 -0,2 0,0 Pre-dawn leaf water potential (MPa) Correlation between berry sugar content and minimum pre- dawn leaf water potential (Merlot, 1996-2003) 250 Berry sugar content (g) 2 R = 0,5527 240 230 1 cultivar, 8 vintages 220 210 200 190 180 -1,0 -0,8 -0,6 -0,4 -0,2 0,0 Pre-dawn leaf water potential (MPa) Correlation between berry sugar content and minimum stem water potential (Merlot, 2000) 270 Berry sugar content (g) 2 R = 0,7132 260 250 1 cultivar, 1 vintage 240 230 220 210 -2,0 -1,5 -1,0 -0,5 0,0 Van Leeuwen, 2004, Grapes, wine and Stem water potential (MPa) environment, Roanoke (Virginia)
  • 49. Correlation between vine water status and grape malic acid content Correlation between berry malic acid content and minimum pre- dawn leaf water potential (Merlot, Cabernet franc, Cabernet- Sauvignon, 1996-2003) 60 3 cultivars, 8 vintages Malic acid (meq/L) 2 R = 0,214 50 40 30 20 10 0-1,0 -0,8 -0,6 -0,4 -0,2 0,0 Pre-dawn leaf water potential (MPa) Correlation between berry malic acid content and minimum pre- dawn leaf water potential (Merlot, 1996-2003) 50 1 cultivar, 8 vintages Malic acid (meq/L) R2 = 0,165 40 30 20 10 0 -1,0 -0,8 -0,6 -0,4 -0,2 0,0 Pre-dawn leaf water potential (MPa) Correlation between berry malic acid content and minimum stem water potential (Merlot, 2000) 50 Malic acid (meq/L) R2 = 0,5248 40 30 1 cultivar, 1 vintage 20 10 0 -2,0 -1,5 -1,0 -0,5 0,0 Van Leeuwen, 2004, Grapes, wine and Stem water potential (MPa) environment, Roanoke (Virginia)
  • 50. Correlation between vine water status and grape tartaric acid content Correlation between berry tartrate content and minimum pre- dawn leaf water potential (Merlot, Cabernet franc, Cabernet- Sauvignon, 1996-2003) 100 3 cultivars, 8 vintages Tartrate (meq/L) 90 80 70 60 50-1,0 -0,8 -0,6 -0,4 -0,2 0,0 Pre-dawn leaf water potential (MPa) Correlation between berry tartrate content and minimum pre- dawn leaf water potential (Merlot, 1996-2003) 100 Tartrate (meq/L) 90 80 1 cultivar, 8 vintages 70 60 50 -1,0 -0,8 -0,6 -0,4 -0,2 0,0 Pre-dawn leaf water potential (MPa) Van Leeuwen, 2004, Grapes, wine and environment, Roanoke (Virginia)
  • 51. Correlation between vine water status and grape anthocyanin content Correlation between berry anthocyanin content and minimum pre-dawn leaf water potential (Merlot, Cabernet-franc, Cabernet-Sauvignon, 1996-2003) 2 1,20 Anthocyanin (g/kg) R = 0,2246 1,10 1,00 3 cultivars, 8 vintages 0,90 0,80 0,70 0,60-1,0 -0,8 -0,6 -0,4 -0,2 0,0 Pre-dawn leaf water potential (MPa) Correlation between berry anthocyanin content and minimum pre-dawn leaf water potential (Merlot, 1996-2003) 1,20 R2 = 0,4865 1 cultivar, 8 vintages Anthocyanin (g/kg) 1,10 1,00 0,90 0,80 0,70 0,60 -1,0 -0,8 -0,6 -0,4 -0,2 0,0 Pre-dawn leaf water potential (MPa) Correlation between berry anthocyanin content and minimum stem water potential (Merlot, 2000) 2 2600 R = 0,7799 Anthocyanin (g/kg) 2400 2200 2000 1 cultivar, 1 vintage 1800 1600 1400 1200 -2,0 -1,5 -1,0 -0,5 0,0 Van Leeuwen, 2004, Grapes, wine and Stem water potential (MPa) environment, Roanoke (Virginia)
  • 52. Among other factors , low nitrogen supply increases grape potential for red wine making Low N High NN-tester values 446 525Assimilable must nitrogen (mg N/L) 63 134Shoot growth cessation (day of the year) 260 269Yield (kg/vine) 1.8 2.2Berry weight (g) 1.67 1.84Grape sugar (g/L) 247 227Anthocyanin (mg/L) 1490 1250Total Phenolics Index 54 43Total acidity (g tartrate/L) 4.7 5.4Malic acid (g/L) 2.0 2.4 Van Leeuwen, 2004, Grapes, wine and environment, Roanoke (Virginia)
  • 53. However, nitrogen deficiency decreases grape potential for white wine making 0N 60 NP-4MMP (ng eq/L) 405 (a) 715 (b)P-4MMPOH (ng eq/L) 760 (a) 2059 (b)P-3MH (ng eq/L) 3358 (a) 14812 (b)Must total tannin content 0.28 (a) 0.21 (b)Glutathione mg/L 18 (a) 120 (b) Van Leeuwen, 2004, Grapes, wine and environment, Roanoke (Virginia)
  • 54. Terroir effect• On most of the variables, the effect of climate > soil > cultivar• Terroir effect is largely mediated through vine water status, which depends on climate (rainfall, ET0) and soil (water holding capacity)• Shoot growth and berry size are reduced in water stressed vines• Malic acid is reduced and anthocyanin is increased in water stressed vines• Grape sugar content is optimum when water deficit is mild• Precociousness of veraison and tartaric acid are not related to vine water status• Low nitrogen supply increases red grape potential Van Leeuwen, 2004, Grapes, wine and and decreases white grape potential environment, Roanoke (Virginia)
  • 55. Control of grape potential• Examples in three different climatic zones Van Leeuwen, 2004, Grapes, wine and environment, Roanoke (Virginia)
  • 56. 1 – Dry meditteranean climate, production of vin red wine • Warm and dry climate: – Sufficient heat degree days to obtain good ripeness – Irregular rainfall • Shallow soil – Limited water holding capacity Van Leeuwen, 2004, Grapes, wine and environment, Roanoke (Virginia)
  • 57. Consequences of climate and soil• Sum degree days allows to bring most varieties to complete ripeness – 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 weight ratio• B) When irrigation allowed and possible - Apply deficit irrigation Van Leeuwen, 2004, Grapes, wine and environment, Roanoke (Virginia)
  • 58. Drought resitant rootstocks…• …tend to be vigourous and so vines tend to develop great 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 and environment, Roanoke (Virginia)
  • 59. 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 and environment, Roanoke (Virginia)
  • 60. 2 – Atlantic climate, red wine production • Climate : – Average sum of degree days – Weak or moderate water deficit • Deep soil : – Not limiting water and mineral supply to the vines Van Leeuwen, 2004, Grapes, wine and environment, Roanoke (Virginia)
  • 61. Consequences of climate and soil• Choice of grapevine variety dependant on 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 and environment, Roanoke (Virginia)
  • 62. Yield should be limitedTo limit yield (in order to respect a leaf area / fruit weight ratio of 1.5) – Spur pruning – Inter row grassing – Bunch thinning Van Leeuwen, 2004, Grapes, wine and environment, Roanoke (Virginia)
  • 63. 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 and environment, Roanoke (Virginia)
  • 64. 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 leaf area Van Leeuwen, 2004, Grapes, wine and environment, Roanoke (Virginia)
  • 65. 3 – Cool climate viticulture, white wine production • Climate – Low sum of degree days – Little or no limitation in vine water supply • Soil – Medium water holding capacity and mineral supply Van Leeuwen, 2004, Grapes, wine and environment, Roanoke (Virginia)
  • 66. 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 soil lime 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 and environment, Roanoke (Virginia)
  • 67. Pest controll is a major issue• Look for cluster aeration• When inter row spacing is limited, cumulated row length per hectare is optimized. – Ideal density is 10 000 vines/ha Van Leeuwen, 2004, Grapes, wine and environment, Roanoke (Virginia)
  • 68. 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 and environment, Roanoke (Virginia)
  • 69. Conclusion• In viticulture grape potential is a major issue• Viticultural practices should be adapted to maximize grape potential (role of limiting factor)• Grape potential is highly dependant on environmental factors (soil, climate)• Viticultural practices should be adapted to environmental conditions (climate and soil)• Production cost should be controlled. However, they can be highly variable depending on the viticultural practices (factor 1 à 4) Van Leeuwen, 2004, Grapes, wine and environment, Roanoke (Virginia)