working on the lower portion of the leaf-canopies--the
cluster-belt--removing leaves in order to to give the grapes exposure to the
afternoon sun as well as to the morning rays. (The side where the morning
sun shines has already been thinned-out in early summer, after the
flowering.) During this process, the old leaves at the base of the
fruit-bearing shoots and side shoots are removed. This serves to shed
sunshine upon the grapes as well as make it possible for the wind to dry the
clusters more easily and thoroughly after a rain or morning dewfall. Getting
sunshine to reach the clusters brings about a more effective retention of
colouring agents in the berries, and it also enhances the development of
tannins. Both of these factors improve the quality of the red wine grapes.
This enables the harvest to proceed more quickly and efficiently, since the
clusters are, shall we say, 'offered up on a silver platter…' This removal
of leaves also helps to maintain the health of the berries. Certainly, the
cluster-belt can be opened out as soon as the process of véraison is nearly
complete—since before there is the danger of sunburn, and the vines react
negatively to a dramatic reduction in the leaf-mass. With our white wines,
the defoliation is done rather late, and to a more limited degree, since
neither the augmentation of colour nor the development of tannins is
desired. In this case it's done only to maintain the health of the grapes.
The images:
Photograph #3 shows the east side of the leaf canopy, which has been opened
up after the flowering. The sunshine is striking this side with less
intensity, so the grapes aren't susceptible to sunburn
Photo #4 shows the west side of the leaf canopy of a vine before defoliation
Photo #5 shows the west side of the same vine's canopy after defoliation.
