That's it, all Vinoland's grape varieties are up and running. Now, if the Cabernet vines can just put on a few inches of growth without damage from a severe frost, the 2012 vintage looks like a go. Of course, it's early days yet, but with the production of more and more green tissue the grapevine increases it's cold hardiness. The accumulation of soluble sugars, which actually begins the preceding autumn, acts as a type of antifreeze. These reserves of carbohydrates, stored in the roots and the dormant buds of the grapevine, are what the winegrower, who has no frost protection system in place, relies on to avoid frost damage.
Among soluble sugars, raffinose appears to be the most important to cold hardiness. The elevated concentration of this carbohydrate in the basal tissue of a grapevine, exactly where the new budettes appear, apparently increases the tolerance to freezing temperatures in Vitis species. The nascent leaves then begin the process of photosynthesis with gusto, producing additional soluble sugars that further help to stave off tissue death and, additionally, synthesise light energy to accelerate vegetative growth. An amazing process.
Go little buddies!
5 comments:
F&F...frost and fungus are the two biggest enemies of our local grapevines. The frost threat usually only lasts through April, but the fungal problems can continue up to harvest as we saw last year. Mold on a barrel aging in the cellar is one thing, but clinging to the clusters is another issue, unless it is encouraged for a late harvest wine style. The war on fungus has begun for this year already!
Yes VM, spray early and spray often!
Vinogirl, a technical question:
What are the proper terms in English for "open leaf" and "extended leaf"? The Italians make a distinction between the two but I can't find the English terms... thanks in advance...
Lot going on there with the natural antifreeze, no wonder it's so hard to make good wine...
2B: I don't think there are any particular words in viticulture for individual stages of leaf development, just the rate of growth (e.g. grand period of growth).
ALW: Makes it easier to drink a good wine though.
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