Trimming a grape vine?

my grandfather has 2 scupalong grapevines in his backyard and he is asking me to look on the net to figure out how to trim them. i looked on google and couldnt find **** and i also looked on ask jeeves and didnt find anything so if anyone could help i would greatly appreciate it!

Trimming a grape vine?
It seems to be several opinions about how best to prune grapevines. In general however, there are really two important factors that you must keep in mind for a successful crop of grapes and a well maintained vine. The first is the time of the year. Grapes should be pruned while they are still dormant. If you cut them later on, when the sap arises, they will bleed heavily, causing a big trauma on the plant. The next important factor is that grapes only fruit on new wood: The canes that had grapes last year won't bear again and you must remove them. On already established vines, select two or three canes arising off the main trunk, about the thickness of your index finger and trim them back to approximately 8 to 10 buds each. Remove the rest of the vine leaving only the main trunk with its three canes. Grapevines are extremely hardy, and the harvest is much improved with heavy pruning each year.
Reply:After picking all the grapes, trim branches to desired height or length. The sniped end will not grow and new branches could start and make the vine bush thicker.
Reply:google "pruning grape vines"! and look especially at the ones with .edu as these are educational sites!! there are many!!

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