Wind


Main effects and symptoms

  • effects Mechanical
The wind can tear leaves, shatter inflorescences and disarticulate twigs. These mechanical injuries cause a reduction in the harvest, but also promotes the development of fungi responsible for esca or eutypiosis . On young stumps, the wind sometimes leads to unwanted bends and permanent breaks.
 
The wind promotes the evaporation of water from the soil and the evapo-transpiration of plants, which leads to water stress. Thus, the strong evaporation induced will decrease the yield of photosynthesis; in this case, the vines sometimes have a puny appearance in windy regions. It also contributes to the erosion wind of sandy soils by modifying the leveling of the latter, some stumps finding themselves silted up while others will be more or less "bare". It should be added that a sandy wind can also be the cause of a decrease in the number of shoots, reduced growth, partial or total defoliation, or even leaf malformations.
 
The grape varieties seem to have different sensitivities to the wind: very sensitive grape varieties: Ugni blanc, Sauvignon, Clairette; sensitive grape varieties: Chasselas, Pinot, Sémillon; moderately sensitive grape varieties: Chardonnay, Grenache, Plantet; not very sensitive grape varieties: Merlot, Cabernet sauvignon, Mauzac.
 
  • Chemical effects
Near the seafront, sea winds laden with spray and therefore salt cause burns on the most exposed leaves. This phenomenon can occur up to several tens of kilometers inland.
  • Pathological effects
The wind influences more or less favorably the biology of pests. For example, by accelerating the drying of vegetation after a rain, it makes it possible to limit the germination of fungal spores or even their sporulation; on the other hand, it promotes the dispersion of spores and insects.
  • Thermal effects
In the south of France, the winds sometimes carry warm air as well as red sand. These hot winds are suffocating and the vine is immersed in excessive heat. The effects of the latter are materialized by a general browning of the vegetation, associated with interveinal drying of the leaves. The branches are burnt by sector with necrosis of the bast.


Preventive measures

In order to limit as much as possible the effects of the wind on the vines, we can play in particular on two parameters:

  • the trellising ensuring a good positioning and a good maintenance of the vine shoots, and therefore avoiding breakage;
  • a limited vigor, less conducive to an exuberant vegetation which is always more tormented by the wind.
Last change : 04/20/21
Vent_Vigne
Figure 1