Sudden cold snaps adversely affect grapevine cultivation
While temperatures that gradually decrease normally allow vines to acclimatize themselves and reach optimal hardiness, rapid decreases in temperature put vines that have not yet had time to adapt at risk. The hardiness of vines is dynamic: it varies greatly in spring and fall, evolving according to biochemical and anatomical changes. While our counterparts in Western Canada pay for helicopters to sweep the warm air from the sky with propellers, the vast majority of Quebec growers do not have the income to use this method, and must therefore resort to more affordable solutions. The use of portable wind machines is one of the options.
Portable wind machines to redistribute warm air masses
What’s a portable wind machine? Portable wind machines are wind turbines that can be moved as needed and according to weather conditions, can be folded up and promise low energy consumption. What are they used for? Wind machines are used to redistribute warm air masses to the colder areas of the vineyards, thus reducing the formation of frost pockets. They can also be used for other purposes, such as drying fruit after a heavy rainfall.
A unique installation for each individual enterprise
The use of portable wind machines is not an exact science and it's impossible to reproduce a method by "copy and pasting" it in every vineyard. Each site has its own specific requirements and sometimes even unique microclimates. Pockets of frost form in a variety of ways on a site, depending on different factors: notably slopes, surrounding vegetation, prevailing winds, water masses or geographical orientation. It is therefore quite understandable that the location of the machines must be determined specifically according to the terrain in which they are installed. If the machines are poorly placed, they could create the opposite effect of what was intended and draw cold air into the vineyard. Local growers are now testing the effectiveness of these portable wind machines under their own circumstances, by carefully studying the specific characteristics of their sites. "Observe" and "analyze" are the words to keep in mind.
VineAlert Vinalert is a tool that was created to be used as a decision-making aid to assess the risk of damage to vines. This website provides a database shared between researchers and growers, which can be useful to further optimize the use of wind machines.
Sources: Vine and Wine Webinar Series 2023. CRAAQ.