Thursday, December 11, 2008

Chip bud grafting / This Earth is mine

Trivia question: Who’s name at birth was Leroy Harold Scherer, Jr.?

He starred in a movie called This Earth Is Mine (released June,1959). Lots of the filming for this movie was done in the Napa Valley, especially in the Yountville, Oakville & Rutherford areas. It’s not considered a great movie, but it’s kind of fun to catch some glimpses of the Napa Valley landscape from 50 years ago. For those of you that haven’t peeked ahead for the answer, Rock Hudson was Leroy Harold Scherer, Jr. at birth. “Rock Hudson? Who’s that?” My 22 year old son Tyler asked.

I won’t go into the plot, but there is a scene where Rock needed to perform a fairly specialized procedure in vineyard operations – Chip bud grafting (AKA budding). Budding is the process of attaching a bud from one plant to rootstock. Rootstock is defined as a plant onto which another plant is grafted. There are lots of different rootstocks available, all with different characteristics. Some are more resistant to pests, Some handle wet or dry conditions better than others. And they tend to have no-nonsense names. Our Firehouse vineyard has 110R, 420A and 3309 rootstock. Once the rootstock has been decided, any variety of grapes can be grafted onto it. Cabernet, Chardonnay and Zinfandel can all use the same type of rootstock. For that matter, you could add a bud from each of these varieties onto the same rootstock for a vine that would produce 3 different types of grapes. Don’t know why you would want to do that, but it is possible. Not to further confuse anybody, but there are several clones of grape varieties, too. Our Firehouse vineyard has Cabernet Sauvignon clones of 2, 4, 8 & 337. The possible combinations of rootstock & varietal clone are almost endless.

I’ll follow this up with some pictures that should make the process easier to understand. Back to the movie: They needed somebody to teach Rock how to bud, and since he was left handed, they needed a teacher that was left handed… and this is where my great uncle Jim Pavon, enters the picture (figuratively speaking, only). He taught Rock how to bud well enough to pass for the movie. Rock even used Jim’s budding box & knife in the movie. I have always found this skill interesting, but apparently not as much as my brother Larry. Larry claims that when he was around 8 years old, he spent a fair amount of time budding and trying to get vine buds to grow. And he wasn’t going to be limited by conventional thinking. He budded vine buds onto Eucalyptus trees. Our dad told him it wouldn’t work, but he proceeded undeterred, and would give our dad daily updates on his project. Those are the trees visible directly across from the Plumpjack Winery tasting room. They appear to have survived Larry’s experiments, but we won’t be releasing a Cabalyptus wine anytime soon.

Did I mention that in-the-vineyard chip budding is hard on the back? This highly skilled work must be done on your knees. The chip bud grafting process is illustrated with pictures below taken by my brother, John C. Piña.

First, a varietal bud is cut from a pruned cane from a mature vine.
(This is an action photo - see it flying through the air?)

Then the 1st cut on the rootstock is made

2nd cut above first cut

2nd cut extends down to the first cut

And when that little section is removed,
the opening has been created for the chip bud

The chip bud is positioned in the opening
A tight fit is critical for the bud to grow*

This fit required an extra sliver of rootstock to be removed

Once the fit is perfect, a lightweight stretchy vinyl tape is wrapped around the new union to keep the new bud tightly embedded into the rootstock

And the top of the rootstock is cut off to force the rootstock to devote all of the growth energies into the bonding and growth of the bud

* After reviewing this post for accuracy at my request, John noted that while a tight bud fit is important, more important is getting part of the cambium layer of the bud to line up with the cambium layer of the rootstock.

There are newer methods of grafting that are not quite so labor intensive, or skilled. Click on the following link to Practical Winery & Vineyard magazine for a more comprehensive overview of the options available.

Great info there, but John’s pictures are better!

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