Page 53 - Grapevine May-June 2020

Around The Vineyard

form vineyard is typically variable in vigour,
often due to soil variation, but sometimes due
to pest or disease. Unhealthy vines rarely pro-
duce quality wines. Variation in vigour can be
linked to physiological status and canopy micro-
climate, and appropriate selection may be used
to select vines, which are candidates to provide
fruit for icon wines.

3. Vine balance: Proper vine balance is essential
for producing premium fruit suitable for icon
wines. By vine balance, I mean the ratio of fruit
to functional leaf area. Vine balance depends on
the pruning level decision, which ideally should
be related to vine vigour, and there may also be
components of subsequent shoot and cluster
thinning. I obviously think vine balance is more
important than yield per se, but this, of course,
is not the common European perspective.

4. Canopy microclimate: While microclimate
requirements may vary from variety-to-variety
and season-to-season, in general, there is a
need for sufficient leaf and fruit exposure, and
the avoidance of shade. There are trellis and
foliage management techniques available to
achieve such an outcome. My book, “Sunlight
into Wine,” details many such procedures and
their management.

5. Vine physiological status: There are many
aspects of physiological status, and most are
regulated by soil moisture, nutrient supply and
canopy management decisions. As an example,
we have recently found an influence of late-sea-
son foliage health on Pinot Noir wine quality. Join Us at
Booth #B825
6. Shoot tip growth: Regulation of shoot tip
growth is especially important for red wine
quality but also for many white varieties. A
good rule of thumb is that active shoot growth
should stop some two weeks before veraison,
and be associated with early and rapid onset of
veraison and lignification.

7. Disease, pest and environmental stress: For
most commercial vineyards, this is not an issue;
however, heat stress is becoming an increas-
ingly important consideration for many regions
worldwide. Failure to adequately control pests
or disease and to avoid significant stress can

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