Growing Wine Above the Napa Valley

Shatter

I am wondering if other vineyards on Spring Mountain or the Napa Valley in general are experiencing the level of shatter that we have here at Paloma Vineyard? For those of you that don't know what shatter is: It occurs when the grapevine is about to bloom. If there is rain, drizzle or even heavy fog, the blossom will not open and the future grapes do not get fertilized and don't bear fruit! Merlot is a varietal that is very susceptible to shatter. In '04, '05 and '08 we suffered from shatter, but this year is the worst yet. We have lost over half of our crop!

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Permalink Reply by Tom Ferrell on August 27, 2009 at 9:35am

A couple of comments, Sheldon. First, my experience is that Merlot and Malbec are more susceptable to shatter than other varieties. Second, though weather during this years bloom is undoubtably the cause of shatter in Paloma Merlot, weather interfering with fertilization isn't the only issue with shatter. It can be a number of vine metabolic issues or vineyard practices that result in the vine tissues being deficient in sugar. Pruning that is too early or too severe, excessively fertile soils or overuse of fertilizers, and improper selection of rootstocks or clones may encourage vigor and shatter. The foregoing are non-existant or extremely rare on Spring Mountain, but more common elsewhere.

I snooped around a Spring Mountain vineyard the other day looking at Cabernet blocks. One block had a beautiful crop of Cabernet with full, long clusters. The other a hundred yards away in same exposure, pruned, trained, and farmed exactly the same had a lot of shatter and easily half the crop. My guess it was related to the timing of flowering and our late Spring rains.

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Permalink Reply by Sheldon Richards on August 27, 2009 at 11:44am

I've seen bad shatter in some other SMD vineyards as well. I guess my next question is what to use or what to save? I don't want all of the shot berries and old dried out flowers in my wine, so I have dropped almost all of them. Plus, I find when you have just a few berries on a stem, the tend to dehydrate and raisin too much to be good for the wine. But I do see some of my neighbors leaving them on the vine to be picked I assume.

Tom Ferrell said:

A couple of comments, Sheldon. First, my experience is that Merlot and Malbec are more susceptable to shatter than other varieties. Second, though weather during this years bloom is undoubtably the cause of shatter in Paloma Merlot, weather interfering with fertilization isn't the only issue with shatter. It can be a number of vine metabolic issues or vineyard practices that result in the vine tissues being deficient in sugar. Pruning that is too early or too severe, excessively fertile soils or overuse of fertilizers, and improper selection of rootstocks or clones may encourage vigor and shatter. The foregoing are non-existant or extremely rare on Spring Mountain, but more common elsewhere.

I snooped around a Spring Mountain vineyard the other day looking at Cabernet blocks. One block had a beautiful crop of Cabernet with full, long clusters. The other a hundred yards away in same exposure, pruned, trained, and farmed exactly the same had a lot of shatter and easily half the crop. My guess it was related to the timing of flowering and our late Spring rains.

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Permalink Reply by Tom Ferrell on August 27, 2009 at 12:31pm

Regarding what to leave and what to drop I could not say with any confidence...except we might find out with the use of the sorting table and separate wine lots.

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Permalink Reply by Ron Rosenbrand on September 4, 2009 at 8:39am

I have a tremendous amount of shatter in our Merlot this year. Other varietals weren't affected at SMV. I have also talked to others on Spring Mountain and seen some vineyards first hand, it seems that everyone that has Merlot has some degree of shatter.

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Permalink Reply by Tom Ferrell on September 4, 2009 at 2:27pm

Stu Smith reports the same thing here in an interview on The Cork Board.

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Permalink Reply by perry butler on September 4, 2009 at 4:17pm

At Juslyn we had no shatter of our Merlot but did have problems with our P.V. Maybe 20% of our crop was lost to shatter . We are at 700 feet which makes a big difference for the Merlot . Cab is looking great .Picked our S.B. today from the valley floor .Great fruit and very tasty.

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Permalink Reply by Andrew Schweiger on September 5, 2009 at 9:48am

No shatter to report at Schweiger in Merlot or Malbec. Very healthy crop all the way around. Merlot about 10% above normal, Malbec normal, Cabernet 20% of normal. Looking forward to a fun harvest!