Viticulture 101: Grapevine canopy management part one
Like wine? Want to better understand the winemaking process? Most winemakers will tell you that great wines start in the vineyard. So here’s your opportunity to learn more about how wine grapes are cultivated. In our Viticulture 101 series, we will explain the basics of the different growth stages, just as many of Oregon’s vineyards are experiencing them. Follow along as we walk you through the 2016 growing season.
Following our last article on grape bloom, flowering and fruit set in the vineyard, we now focus our attention on canopy management. The canopy of a grapevine is really anything that grows above ground (as opposed to the roots). This includes the leaves, flowers, stems, trunk and most importantly, the fruit. And it’s essential to understand how skillful maintenance can affect grape ripening and yields, as well as overall plant vigor and disease prevention.
In Oregon’s Willamette Valley, canopy management is a crucial part of the wine grape growing process. Without it, we see more mildew, uneven cluster ripening and sometimes sunburn on our delicate grapes.
As we mentioned in an earlier article about pruning grapevines, most vineyards use a trellising system upon which to grow their grapes. Usually these trellises are designed to hold the canopy with catch wires that can be adjusted upward as the plants grow taller. Some trellis systems, such as the Scott Henry method, have catch wires that promote growth both upward and downward.
Shoot positioning requires hands on each vine’s new shoots. It’s a labor-intensive process that the vineyard managers use to manage the new canopy growth as the grapevines mature. Each new shoot must be carefully coaxed under the catch wires as the grapes grow taller to ensure tidy and accessible rows. Otherwise it would quickly turn into a jungle! Careful positioning will eliminate significant overlap between the shoots, avoiding excess shading and diminished air circulation as more leaves grow on each plant.
As the grapes grow, vineyard managers also use a technique called shoot thinning and suckering to remove excess growth that might deter from premium grape quality. Most wine growers are looking for about 4-5 shoots per foot. Any more than that are removed, particularly any secondary or tertiary shoots that have popped up. Suckers are any new growth stemming from the trunk of the grapevine and are generally removed as well.
Canopy management is imperative for growing healthy grapes. But it doesn’t stop with shoot positioning, thinning and suckering. In part two, we’ll discuss the benefits of leaf pulling and hedging the grapevines for optimum quality. But first, watch for our next article on veraison, when the grapes begin to ripen!