Wine Production : Vine to Bottle - Vinum Vine

15
2.2.3 Strong winds
These can have a dramatic effect by damaging canes, breaking
shoots and removing leaves. Spring sun and severe wind can be a
devastating combination for young shoots and leaves or very young
vines. If prevalent when the vine is flowering, then poor pollination
and a reduced crop can result.
The detrimental effect of strong winds may be a particular problem
in valleys, which can act as funnels. For example, on the steeply
terraced hillsides in the northern Rhône valley, vines have to be
individually staked, whilst in the flatter southern Rhône, rows of
conifer trees have been planted to break the destructive force of the
Mistral wind. In other areas, forests and mountain ranges offer some
measure of protection.
CHAPTER 2
2.2.4 Excessive heat
Heat stress can be harmful to the vine. When there is excessive sun
and temperatures exceed 40 °C (104 °F), the vine can shut down
and photosynthesis ceases. Thus no more sugars are formed and
ripening stops. Grapes can be sunburnt and scarred in the hot
afternoon sun.
2.3 Mesoclimate and microclimate
There is often confusion between these two terms. Mesoclimate
refers to the local climate within a particular vineyard or part of
a vineyard. Microclimate refers to the climate within the canopy
of leaves that surrounds the vine. There are several factors that
influence the mesoclimate of any vineyard area.
2.3.1 Water
Nearness to water, whether rivers, seas or lakes, can bring the vines
the benefit of reflected heat. Water can act as a heat reservoir,