What kind of pruning goes on in a vineyard?

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Dear Dr. Vinny,
What kind of pruning goes on in a vineyard?
—Laney, Jackson, Ohio
Dear Laney,
Pruning doesn’t get a lot of attention, but it’s a really important part of managing a vineyard. At its most basic, pruning refers to removing branches, foliage or fruit. But it’s much more complicated than that. Pruning decisions impact the volume and quality of grapes come harvesttime, and also present an opportunity to control disease and address vine damage.
Left on its own, a grapevine will sprawl and spread itself out, producing as many leaves and as much fruit as it can. You might be thinking, “More grapes! What’s wrong with that?” But unchecked grapevines yield more grapes than grapegrowers are looking for—huge crops can ripen unevenly and usually result in grapes that lack the intensity of flavor needed to make great wine. Pruning helps focus the vine’s energy on producing a smaller volume of the best grapes possible.
There are several phases of pruning, but when we talk about pruning a vineyard, we’re usually talking about removing canes (woody vine branches that are at least two years old) and spurs (younger branches, usually one year old) between growing seasons, sometime during late winter or early spring, when the vines are still dormant. Cane- and spur-pruning strategies depend a lot on the vine-training system in use, and climate can influence those choices as well: If the vines are pruned too early, new growth might be damaged or killed by a late frost; prune too late and the new shoots are left playing catch-up with the growing season.
Pruning canes and spurs helps set the stage for the upcoming growing season, preventing overcrowded vines, and ensuring that the grapes will have plenty of room for air to circulate, which helps prevent mildew and rot.
There are some key pruning strategies during the growing season as well, but we use different terms for those. Canopy management includes leaf pulling and other methods of controlling vine vigor and grooming the leaves and shoots that surround grape clusters in an effort to optimize the clusters’ sun exposures and the flow of air around them, and green harvesting is the practice of dropping excess clusters of unripe grapes during the growing season to reduce yields and concentrate flavors in the remaining grapes.
—Dr. Vinny