challenges-P&D

Question 1

Which disseases of the vine are the greatest thread to vyd around the world today and why?

Answer 1

1. Esca-Eutypa
   - Francois Dal -couretage
   - Agustin Santi 5%- Cloudy Bay- SB suceptible
   - Prunning Matteo Simonit
   - Burkling Wolf 15% loss/year for Esca (Riesling susceptible)
2. Viruses
   - Red blotch - 12% CA- Napa Valley wine growers
   - Fan leaf-leaf roll - vector management- deadly- Sabrina massola
3. Fungal
   - Powdery Mildew (oidium), Botrytis cinerea
   - Eva Frickle (rhiengau) <3kg/ha Cu for organic new limits. Supplement with Ca/Mg and
   canopy management
   - 5-17 sprays of Cu/year Jurgen Amthor- Cabernet Cortis- Franconia- reduced applications from 20 to 2 times a year
   dry climate: Miguel Galet Vina Ventisquero: comprehensive canopy management and citric oils (dry)
   Qual, yield and cost for prevention+ compactation + contamination for tracto

Downey Mildew,Fungicides: - Demethylation inhibitors (DMIs)
- Phosphonate (phosphorous acid) - 200 mg/kg

4. other
   - Flavesance Doree
   Christophe chauvot A. Bichot- prefers feromone traps vs insecticides -Pyrethyne -kills all insects (but are mandatory)

Question 2

22. What effect do vineyard pest have on grape quality and how do wine growers control them?

Answer 2

1. large animals- permanent damage - fences and shootters
2. insects affect plant at different digrees
   - Vectors Leafhoppers (flavessance dooree)- Millibugs (leafroll)
   Christophe chauvot A. Bichot- prefers feromone traps vs insecticides -Pyrethyne -kills all insects (but are mandatory)

• lowers vigour/yield- kilss
  Nematodes: =20%-60% reduction in yield, Common in sandy soils - Riverland Au
  Managed through pre-planting evaluations heat treatments, Ramsey rootstock, soil fumigation, and natural bacteria.

-Lobesia Botrana lowers colour and sugar
- galet pheromone traps
_Phyloxera lower colour and sugar- kills SO4 Humberto Jardim H&H

3. small birds and roedents
   open wounds to fungal infections
   dicrease yield
   -nets- shoots sound- fences- Integrated pest managament

Question 3

23. Extreme heat and drought threten many wine regions. What steps can a vineyard manager take to mitigate its effects?

Answer 3

min of 600 mm a year. Drough-prone regions, < 300 mm a year | over 40C is shut down metabolism

1. Cover cropping and mulching.
   Spier, Stellenbosch: Comprehensive approach with animals and high-density grazing; increases in soil organic matter by 2% can double water holding capacity.
   Tablas Creek, Paso Robles: Practices dry farming, biodynamic, and regenerative organic farming; uses sheep for rotational grazing, biochar, cover crops (rye grass, fescue, chicory), and keyline plow for better water absorption.
2. Drip irrigation and precision technology.
   Daniel: 4x25ml during growing season to promote deeper root growth.
   Miguel Galet: Uses drills for water collection and precise irrigation on demand. Only 800 m3/ha/year
   Fruition Science, US: Sap-flow monitoring results in up to 60% reduction in water and energy usage.
   Familia Torres, Catalonia (2023): Faced 54% less rainfall than historical average; implemented water conservation, soil recovery, vine training (gobelet), and contour farming. A legal change is required
3. Canopy Management
   Shoot positioning, shading, deleafing- Matias Macias
   Sunscreens and shade cloths.
   Semillon, Hunter Valley: bruce Tyrell Uses kaolin clay up to 40°C.
   Steve Lohr, Paso Robles: Uses shade cloth to retain 5-10% higher yields and prevent fruit desiccation.
4. Change cultivar, grafting, introducing new heat-resistant varieties.
   Heat-resistant varieties: Australia, Koerner- Vermentino (thick leaves), Mourvèdre (deep roots). Ian Hongell, Torbeck: Opposes changing established methods, maintains bold style.
   David Forrer MW, Priorat: Uses biochar for water retention; focuses on carinena/mazuelo for their drought and heat resilience.

Rootstocks Debate: Sebastian Labbe, Santa Rita: Replanted CS on 100R - Miguel Galet, Ventisquero: Notes excessive vigor and more water demand with 110R.

Question 4

23- A viticulturist has observed a declien in yield in the past 5 years. Discuss the possible causes and how the issues might be adressed.

Answer 4

1.Climate Change Impact on Vineyards
OIV Report 2023: Vine yield 7% lower than previous year, worst since 1961 due to frost, heavy rainfall, and drought.
Water Legislation: Torres suggests possible legislative changes to address water shortages.
Rootstocks and Grafting: Considerations for adapting to climate challenges.
Steve Lohr, Paso Robles: Uses shade cloths to enhance yield by 5-10% and prevent fruit desiccation.

2. Pests and Diseases
   Common Issues: Esca (Francois Dal - couretage), Red Blotch, Pierce’s Disease, - vectors-
   Nematodes, Lobesia Botrana -insecticides-
   Management Strategy: Integrated Pest Management to control vineyard pests and diseases effectively.
3. Soil Management
   Compaction: Affects soil health.
   Nutrient Deficiency: Lack of nitrogen and organic matter; excessive pesticide use reduces soil diversity.
   pH and Soil Type Adjustments:
   Acidic Soils: Christiaan Loots at WaterKloof regularly adds lime (1–4 t/ha).
   Sodic Soils: Use of gypsum to replace sodium with calcium and regular leaching to remove salts.

4.Vineyard Management Practices
Pruning Mistakes: Simmonit
Soil Coverage: Use of cover crops to compete with vines, careful deleafing and pruning.
Organic Transition: Initially reducing chemical and fertilizer inputs may lower yields by 20%.
Natural Vine Ageing
Christophe Chauvot: Decision to remove CH GC-12 part of managing vine ageing.

Question 5

What are the Causes and effects of Nitrogeen deficiencies in the vineyard? How can be remedied?

Answer 5

1. Nitrogen Deficiency Leading to Poor Growth
   Cause: Insufficient nitrogen due to poor soil fertility or inefficient nutrition systems.
   Effect: Reduced vine growth and yield, impacting essential compound production (DNA, proteins, pigments).
   Solution:
   Conduct soil and vine testing.
   Use legumes and organic matter.
   Implement integrative approaches like Spier SA.
   Fertilization strategy by Danisa Calderon at Deevines: 50kg/ha in 2-3 applications, crucial for fermentation.
2. Nitrogen Present but Unavailable to Plants
   Cause: High soil pH (>6) or drought conditions.
   Effect: Lower vigour, similar to nitrogen deficiency, including yellowing leaves.
   Solution:
   Marcelo Belmonte recommends nutrition drip systems to enhance root access and prevent leaching.
   Address compact soil with tilling.
3. Unbalanced Plant
   Cause: Nutritional imbalance.
   Effect: Reduced yields, excessive shading, increased disease susceptibility, and uneven ripening.
   Solution:
   Employ canopy management and deleafing.
   Reconsider training systems.
   Example: Cabernet in California managed by Sabrina Massola.
4. Competition from Weeds or Cover Crops
   Cause: Weed or cover crop competition for nutrients.
   Effect: Similar effects as nutrient deficiency, leading to weakened, unbalanced vines.
   Solution:
   Weed removal using methods like Randap.
   Reconsider the use of certain cover crops.
   Example from Plancic, Croatia.

Question 6

To what extent is exessive precipitation during the growing season a theat in the vineyard? How can it be managed?

Answer 6

1. Budbreak
   Mildew Risk: use preemptive fungicides. Cu
   Vineyard Structure: Ensure robust support systems against waterlogged soils.
   Management: Implement drainage, maintain strong trellis systems. Younger vines might be more succeptible to structure damage
   Lorenzo Pasquini Estate Manager
   Chateau d’Yquem higher rainfalls is
   spring creating higher pressure of downy mildew
2. Flowering/Véraison
   Flowering- millerandage and lower yiedling risks
   Excessive Green Growth: canopy management
   Nutrient Leaching: Nutrients washed away; adjust fertilization schedule.
   Management: Control canopy, replenish nutrients timely.
3. Pre-Harvest/Harvest
   Difficult Access: Wet soil complicates vineyard operations. No mechanization.
   Mildew and Rot: Increase in moisture-related diseases.
   Dilutes flavors, acid and sugars if close to harvest.
   Management: Flexible harvest planning, targeted fungicide applications.
   Loire-Paul Henrie Pelle

CA-Mendoza

4. Pruning
   Excessive Growth: Vigorous growth increases pruning workload.
   Vineyard Structure: Water damage may necessitate frequent repairs.
   Management: Thorough pruning for balance, inspect/maintain trellises.- consider watterlogging rootstocks- Calardis Blanc
   Acesss

Question 7

19. Mildews continue to blight vineyards. What strategies might a vineyard manager implement to reduce risk?

Question 8

Identify the most important trunk dissesases in vineyards aeround the world. How can they best be managed?

Question 9

What are the principal pest and diseases facing wine groweers today and how can they be best managed?