leaf plucking

[Chuck-crisler]

I grow with a VSP trellis. I didn't know that it was considered the most labor intensive style when I built it. Anyway, I have heard about plucking leaves to increase sun light on fruit shortly before harvest and to promote better air circulation. Does anyone know anything about this? What is the basic strategy? I live in southern New Hampshire and the sun is pretty strong now.

Thank you,
Chuck Crisler
New Hampshire

 

[djrockinsteve]

Yes trim back excessive leaf growth and keep the grounds clean. Air circulation is important.

It can be difficult at first knowing what to trim and where but once you start you can go pretty quick. Basically get rid of those extra cordons and keep your cordons about 3 feet or just above the top wire.

Another advantage to trimming excess growth is you will be able to pick the grapes faster without having growth in your way.

How many vines do you have?

 

[Chuck-crisler]

Thank you for the help. I have 72 vines in the official vineyard and 6 table grapes on a separate trellis.

Most of my leaves are in the top sections of my trellii (?). The fruit is lower with fewer leaves, but there are some. I could pluck a few leaves in the fruiting section to improve sunlight penetration, but there aren't too many to begin with. Different varieties do have different growth habits. Some are quite rampant (Frontenac, some of the Foch and, to a lesser extent, Marquette).

I googled this and got an interesting hit.
https://winemakermag.com/658-ten-signs-of-a-healthy-vineyard-backyard-vines

In section 5 he discusses canopy management and mentions that you get vegetative flavors if you have too many leaves. He suggests 12-15 leaves per cluster. Is this true (the flavors part)? I always thought that more leaves were better because it meant more sugar.

I guess the thing is to pluck around high noon (yuck) when you can see where the sun is.

 

[grapeman]

You don't want to strip all the leaves and leave the clusters totally exposed, they can sunburn and rot. Just thin them so the clusters get a dappled sunlight. Unripe fruit has more of a vegetal flavor and some varieties are worse than others. If your leaves are sparse to begin with, you may not need to thin. There are studies of the best time to thin the leaves with some wanting it early to allow th grapes to adjust to the extra sun and then those that want to wait until veraison to thin the leaves.