Round bunches like this are slow ripening, and can be removed during late crop thinning.
Compare the color of leaves in the background with two leaves held in the foreground, indicating nutrient deficiency.
Growing shoot tips in early summer. The position of tendrils near the tip, and the internode length at the tip indicate the vine’s water stress.
Three different clones of grapes were found by close observation in this Tasmanian vineyard, which was thought to be all “Pommard” clone, the middle group of bunches.
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Of course, such an impression is
transient and not so useful for management.
I have been for 30 years a fan of
aerial infrared imagery, having first
used it to detect phylloxera in the early
1980s in New Zealand. Aerial infrared
imagery is now the basic tool for our
commercial vineyard grading service.
In addition to assessing these images
by eye to see patterns, one can also
extract pixel data.
Sometimes one’s eyes can also be
used to determine differences in soil
types within vineyards by their color,
but this is not always reliable.
Important soil factors of depth and
water -holding capacity are not always
visible at the surface.
Another good example of the merits
of close vineyard observation involves
the clonal selection of Pinot Noir in
Tasmania, which I have been doing
over the last few years. I initially do
this at veraison, with a follow-up visit
before harvest. Much of our work has
been in a vineyard with the
“Pommard” clone.
I have found, to my amazement,
that what was regarded as a monoclonal
vineyard in fact, contains
two clones besides Pommard.
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One is
effectively non-fruiting, and is 10%
of the vine population. Another is a
large, tight bunch clone which is an
obvious mix up with the Pommard
clone. Hopefully such a vineyard is
not to be found on many properties
today, with more strict controls over
nursery practice.
At the vine level
In my experience, little can be
learned about vines as they pass
through bud-break, although one likes
to see this happen promptly. Early
shoot growth can be the first important
indication of vine health, as for example,
“spring fever” can indicate deficiency
of potassium, and yellow leaf
color possible deficiencies of nitrogen
and sulfur.
Before shoots have grown to six
inches long is a good time to do shoot
thinning, a common practice in the
U.S., but not inAustralia.My approach
is to make a visual assessment of shoot
density, to be supported by some rapid
vineyard monitoring before a decision
to thin or not.
Observation can also detect diseases
and pests, though this will not be discussed
here, at length. Most vineyard
diseases present
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clear symptoms, and
generally diseases are well-known
within a region, so that local knowledge
can guide a vigneron as to the diseases
to expect. Occasionally, however,
new pests and diseases may show up,
as was the case with mealybug and
European vine moth in California, and
the multicolored Asian ladybug in the
eastern U.S.
I am not familiar with any disease
that will improve wine quality, and
some dramatically reduce it. Proper
pest and disease management is fundamental
to a higher quality vineyard.
Bloom and fruit set
Bloom is an important time in the
vineyard. An astute observer will note
the duration of bloom and any problems
that may affect fruitset, such as
the adhesion of caps following rain.
My present researchwith PinotNoir
in Tasmania is highlighting cluster
form and location as they affect the
onset and speed of both bloom and
veraison, and potential wine quality.
Although these ideas are yet to be
refined, it seems that the non-classical
bunch shapes sometimes evident at
bloom may be an undesirable contribution
to harvest.
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