Thursday, September 12, 2013

Grapevine chic?

Well, sort of.  These strips of cloth, stretched along the length of the rows in the Rudd vineyard, at the corner of the Silverado Trail and the Oakville Crossroad, may just well be the viticultural equivalent of a cool pair of designer sunglasses - they are designed to keep the sun out of the eyes (humour me, please) of the ripening grapes. 
There are only a handful of vineyards in the Napa Valley (for now) who have decided to adopt this approach in reducing the damaging effects of periods of high UV light, as it is yet another time consuming (and no doubt costly) vineyard operation.  But installing shade cloth on the west facing side of a vine row (in vineyards planted north/south) is indeed a new and novel approach to protecting a grape crop from the potentially intense heat that can occur at this point in the valley's growing season.  The installation of of shade cloth - on hillside vineyards, on vines on low-yielding soils and rootstocks, on vineyards with deficit irrigation programmes, or even in wide spaced vineyards in which the vines receive no respite from harsh UV light in the form of the angled shade from a neighbouring row - can help to promote phenolic maturity (seed-browning and tannin maturation) and not just spikes in sugar accumulation (as a result of dehydration).  The uniform strip of cloth adds sun protection, but still allows for diffused UV light and air circulation around the clusters.
Leaf-pulling may now becoming pass√©, but in Vinoland I still perform this particular vineyard operation - but only on the east side of the vines thus ensuring that the clusters on the west side (that may otherwise be susceptible to sunburn and raisining) each have their own individual parasols.  Now, that's chic.


New Hampshire Wineman said...

Vinogirl, nicely pedagogical!
The photo has beautiful inertia and texture:-)
Are you sure teaching isn't your "calling"?

Thomas said...

It is indeed a fine photo.

Are those vineyards north/south facing?

Vinogirl said...

NHW: Thanks, but I think I'd make a terrible teacher.
Inertia? Probably because my car was moving at the time!!!

Tomasso: I was heading east-ish on the Crossroad (ENE), so this vineyard is planted more NNW in actuality. The valley curves to the left.

Thomas said...

Thought so by the location of the drapes.

Vinogirl said...

Tomasso: Yes, so that side gets all the afternoon sun as it heads towards Hawaii!