Viticulture 2 Phylloxera and rootstocks.txt

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Viticulture 2 Phylloxera and rootstocks.txt
2013-08-22 18:50:56

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  1. ´╗┐What is the correct name of Phylloxera vastatrix (the devastator)?
    Dactylosphaera vitifoliae
  2. Describe 3 defense mechanisms of American vines to Phylloxera
    • Roots mend the wounds caused by the insect, sealing them from invasion by bacteria or fungi
    • Sap clogs the feeding apparatus of the insect
    • Something in the roots causes juveniles to die
  3. On what part of the vine does Phylloxera breed?
    • On American vines, the leaves
    • On European vines, the roots
  4. Name 4 reasons why Phylloxera is so challenging to deal with
    • Adaptability to its surroundings (e.g., Biotype B variant of Phylloxera resistant to AXR1 rootstock)
    • Ability to differentiate between American, European, and hybrid species
    • Different behavior in sandy, clay, or chalk-rich soils
    • Dislike of very hot and wet soils
  5. Phylloxera is parthenogenetic. What does that mean?
    It is able to lay fertile eggs without a male
  6. Almost all Phylloxera eggs laid hatch into females. T or F?
  7. How many generations can a female Phylloxera lay in a single season?
  8. What are galls and where are they seen?
    Galls contain unhatched Phylloxera eggs. The appear on leaves and roots.

    Note: On American vines, these reddish/brown lumps are on the leaves. The eggs hatch into aphids; some turn into crawlers and creep down to find roots. Crawlers inject their saliva into roots causing root galls.
  9. How does phylloxera spread?
    • Spread below ground from root to root and from vine to vine by crawlers.
    • Fertile adults emerge from the soil and crawl across the ground.
    • In warm climates, a winged form exists which can fly about 100m.
  10. The female offspring of the winged form of Phylloxera lays winter eggs. What can it hatch into?
    Fundatrix; the mother ("queen bee") of a new generation in a new location.
  11. When and where did Thomas Jefferson try to establish vinifera vineyards?
    In 1773 he hired Italian grower Filippo Mazzei to establish a 400 acre vineyard adjoining Monticello in Virginia. However, it succumbed to Phylloxera or Oidium (Powerdery Mildew).
  12. When was Phylloxera first seen?
    • 1861: Pujaut, Rhone village (planted 1861, attacked 1863, spread 1865)
    • 1863: Hammersmith, West London
    • 1860s: California
  13. How did Phylloxera spread in Europe?
    • 1872: Douro in Portugal
    • 1874: parts of Spain
    • 1875: first sighting in southern Germany (grubbing with compensation kept under control until WWII).
    • 1879: Italy
    • 1890: Champagne (by this time, grafted vines were established in the south and west of France)
  14. Did the French warn California that AXR1 was not resistant to Phylloxera?
    Yes; contrary to U.C. Davis advice. By 1980s, such vineyards were succumbing to Phylloxera.
  15. What is the correct name of Powdery Mildew (initially called Oidium tuckeri)?
    Uncinula necator
  16. How can Powdery Mildew be treated?
    Spraying/dusting with sulphur
  17. Where was Powdery Mildew found in 1845?
    A greenhouse in Margate, Kent, England
  18. Name some vineyards not planted with grafted vines
    • Chile: Andes barrier
    • Australia: quarantine (e.g., pressure-wash equipment)
    • Argentina: flood irrigation
    • Ernst Loosen: Mosel slate-covered slopes are layered, not re-planted
    • Vin de Sables: In sandy soils of the Rhone
    • Quina do Noval: Nacional vintage port
    • Bolinger: Vieilles Vignes Francaises are planted en foule
    • DRC: La Romanee-Conti and Richebourg (grubbed up in 1945; replanted in 1947 with a selection massale (multi-clone) taken from the old vines.
  19. Define "en foule" ("in a crowd")
    System of random planting where replacement vines are layered rather than re-planted.
  20. Name a recent development in Phylloxera control
    Use of a soil fungus (Metarhizium anisopliae) which infect the pest with a disease that kills it
  21. Is there evidence that the flavor of wine produced from a vine attached to non-vinifera root stock is tainted in any way?
  22. What was a good yield of a top Bordeaux estate before and after the Phylloxera crisis?
    • Before: 10-15 hl/ha
    • After: 60-75 hl/ha
  23. Why has yield increased after the Phylloxera crisis?
    A grafted vine may be more vigorous, have a deeper root system, and denser canopy.
  24. Name 8 reasons to use rootstock
    • anti-Phylloxera: V. riparia, V. rupestris, V. berlandieri best; Borner (riparia X cinerea) best, AXR1 (aka ARG1) (vinifera X rupestris) failure.
    • lime-induced chlorosis: V. berlandieri with high active CaCO3 (calcium carbonate) content
    • nematode resistance: V. champini and V. longii best (e.g., Dog Ridge, Freedom Harmony, Ramsey); crosses with V. vinifera worst
    • drought resistance: V. berlandieri X V. rupestris roots dig deep so best; V. riparia and hybrids worst
    • Salt tolerance: V. berlandieri, V. champini (Ramsey) and viniferas help
    • Promote growth: V. rupestris (e.g., Rupestris St. George, 99R, 110R)
    • Vigor-reducing: V. riparia (e.g., Riparia Gloire de Montepellier (RGM), 420A, 41B, 161-49, 101-14)
    • Advance maturity: in cooler regions
  25. How does root stock affect the characteristics of the same cultivar and clone of a variety, grown on the same site?
    • Time of bud-burst, veraison, harvest
    • yeild
    • pH
    • Sugar and acidity
  26. Once selected, can a rootstock be changed?