Canopy (grape)

Source: Wikipedia, the free encyclopedia.
Grape vines and their canopies

In

grape diseases. Various viticulture problems, such as uneven grape ripening, sunburn, and frost damage, can be addressed by skillful canopy management.[2][3] In addition to pruning and leaf trim, the canopy is often trained on trellis systems to guide its growth and assist in access for ongoing management and harvest.[4]

Vine

The trunk of a grape vine trained along wires with one cordon extending horizontally to the left.

The vine is the main part of the grapevine, extending from the

grape variety and the type of trellis system being used and can range from 4 inches (10 cm) to 30 feet (10 m). During winter dormancy, the trunk can be vulnerable to extreme freezing conditions and will be sometimes buried and insulated with soil to protect it.[5]

The trunk is composed of sleeves of conductive

fruit set by forcing the vine to direct most of its energy towards developing the grape clusters. The xylem is the woody tissue on the inside of the trunk that moves sap, enriched with water, minerals and other compounds, up from the roots to the leaves.[5]

Cordon

The cordon, or "arms", of the grapevine extend from the trunk and are the part where additional arms and eventually leaves and grape clusters extend. The cordons are usually trained along wires as part of a trellis system. This training usually fixes the cordon into a permanent position, such as horizontal extending from the trunk in opposite directions.[6]

Stem

During veraison, when the grapes change color, the shoots of the vine start to harden and brown.

The terms stem, stalks and

bunchstem while the stem of the individual grape berry is the pedicel.[7]

The shoot of the vine develops from new

flowering stage and usually slowly by the time that the vine begins veraison
. During the stage of veraison (typically mid to late summer), the shoot starts to harden and change color from green to brown.

Cane

The shoot is ripening at this point and becomes known as a "cane." In wintertime, the canes of the grapevine are usually completely cut off with the amount and weight of the cane being used to gauge the amount of pruning and canopy management that will be needed for the upcoming year. The "tip" of the shoot is the small (0.4 in/1 cm) part of the shoot furthermost from the vine. Viticulturalist use the growth of this tip as an indication of vine vigor because the tip competes with the grape clusters for resources from the vine. Ideally, shoot growth should come to a stop around the time of veraison; a vine that continues growing the shoots will stand the chance of less fully developed grape clusters.[8]

Leaves

Ampelographers would be able to identify this Chardonnay leaf based on the size and shape of its five lobes and the naked veins around its sinus.(highlighted in box)

A grapevine's leaves are the most visible part of the canopy and also one of the most important. It is through the leaves that the vital

ampelographers use for plant identification. The size and shape of the leaf's sinus (the opening space where the blade of the leaf connects to the petiole), the shape of the "teeth" along the outer edge, the arrangement of the five lobes or projecting parts and the angle and length of the veins can all assist in identifying the grapevine.[9]

The color of the leaf can be an indication of the health and nutrition of the vine. Chlorophyll in the leaf gives it a natural greenish color. Prior to the winter dormancy, the vine will stop being photosynthetically active which will contribute to a natural break down of chlorophyll and changing of color. However, deficiency in nitrogen or sulfur could cause the vine to turn prematurely (such as before harvest) yellow. The appearance of reddish spots of brown "dead zones" could be the sign of a viral infection (such as the leafroll virus) or contamination through the use of herbicides.[9]

Viticulturalist will use a

phenolics and other important compounds in the grape. Many vineyards employ the practice of leaf removal throughout the growing season to try to maintain optimal leaf coverage.[9]

See also

References

  1. ISBN 978-1-875130-10-8
    .
  2. ISBN 978-0-9514703-1-2
    .
  3. ^ Weiss, S.B., D.C. Luth, and B. Guerra. 2003. Potential solar radiation in a VSP trellis at 38°N latitude. Practical Winery and Vineyard 25:16-27.
  4. ISBN 0-19-860990-6
    .
  5. ^
    ISBN 0-19-860990-6
    .
  6. ISBN 0-19-860990-6
    .
  7. ISBN 0-19-860990-6
    .
  8. ISBN 0-19-860990-6
    .
  9. ^
    ISBN 0-19-860990-6
    .
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