How many clusters per grapevine?

[Chingchongly]

I have a third year grapevine. How many clusters is recommended for its third year? Do I increase that amount next year?

I am actually growing them for table grapes, but if growing them in the style of wine grapes makes them tastier, I don't mind growing them like that. If it's worth it.

 

[wood1954]

Do a light crop this year and more next year.

 

[salcoco]

I believe the measurements are when pruning leave at least 4 inches between spurs. about the size of your fist. possible two shoots per spur for a 6 inch shoot one cluster for a 12 inch shoot two clusters. cordon length giving 8 ft spacing between plants no more than 4 ft in each direction forming a "T". reduce this for the three year plant than plan for this arrangement thereafter for following years.

 

[Tim3]

So I’m actually in Napa right now and have been walking around the vineyards and looking like a fool counting the flower clusters. Every mature vine is trained in a single cordon system and is pruned to have 2 buds per spur, with an average of 12 spur’s (vine’s aren’t necessarily symmetrical). So typically 24 clusters per vine. The best vineyards will eventually cut off the less healthy looking cluster per spur as veriason sets in to allow the vine to focus its energy on a more limited number of clusters and end up with an average 12 clusters per vine at harvest. This is a low yielding system at 2 tons per acre, and bulk producers in central CA might go as high as 10 tons per acre. By using a double cordon system and not pruning. Anyway, keep in mind these vines are mature and at 3 years your primary focus should still be building the root system with yield being a secondary focus.

 

[balatonwine]

A vine will try to produce 2 to three clusters per shoot, with 10 to 20 shoots per cane in an average vineyard. A third year vine with good root system and healthy growth can tolerate one cluster per shoot in a managed vineyard. After that, you can go with two clusters per shoot (nip off any additional clusters).

I have delayed some of my vines up to 5 years before allowing them to have their first cluster on any shoot, as I did not consider them "strong enough". So, as with all things, it can depend.