North American Fruit Explorers mailing list at ibiblio

[Mauch1@aol.com]

Well, the answer can be "it depends".  It may also depend on what grape 
you're growing, and
what you plan to use it for.

I can recommend a book, "Sunlight into Wine" by Dr. Richard Smart, but unless 
you can find 
it available used or in a library it is cost prohibitive (~$50).  It is aimed 
at commercial 
wine production So it doesn't deal w/ arbors.  But I can summarize some of it 
here:

1) Late mid-season, the vines should have grown about 10 to 12 leaves (on 
average) beyond 
the fruiting clusters and have terminated growth (you can tell this by the 
fact that the 
last leaf extends beyond the growth tip, if the growth tip is beyond the last 
leaf, its
still actively growing).  
2) If you look at the "plane" of growth, you should have most 1-2 leaves 
between the 
clusters and the sun. Some of this can be achieved by shoot positioning
3) If growth is too vigourous you can get into a "vegetative" cycle.  Vine 
overgrows space,
so you are forced to cut it back, so it forces more growth (at the expense of 
fruiting).
4) Shoots should not be spaced too close together.


Three main ways to achieve the above:
1) Either spacing the vines far enough apart that the vines cover a large 
enought area that
each bud has reduced vigor.
2) Space vines very close together so that they compete for nutrients and are 
therefore 
de-vigorated (this requires special training systems).
3) Shoot and leaf thinning plus "tipping".  Usually shoot thinning earlier, 
and leaf 
thinning around veraison (first coloring of the grapes).

I am concerned that you have too many vines for your arbor space.  You have 
100 square feet
of arbor space which gives you 25 sq. ft. per vine.  I (on my vertical 
trellis) had  6 ft.
per vine on a 6 ft trellis or 36 sq. ft, and I don't think that this was 
enough space.  
You are much further north, so maybe you'll have reduced vigor.

One other note:  downward growing shoots generally stop growing on their own. 
 The upward
growing ones would be the real problem as they would eventually flop over 
onto the other
shoots and over shade your clusters.

Chris Mauchline
SE PA, zone 6

<<
Hello,

I am relatively new to grapes and seek some advice.

Last year was the second year for the grape arbor.  It is 10'x10 square and 
8' high.

The 4 main vines now go up each of the corner posts and criss cross the 
timbers at the top.  While it
was dormant I pruned back to the mains, and I have new fruiting shoots coming 
in (I am sorry that I
am using the wrong terminology).

My question is; Is any pruning performed during the growing season?

Shoots that are near cross members I train to the cross members with jute, 
but what about those
shooting out into space, away from the arbor, are they removed now, or left 
till dormant pruning?
Will a shoot hanging in open space stop growing for lack of support?

Thanks for any help you can offer.

Regards,
Tom
>>