DR. MACDANIEL: Is that always with the Franquettes?
DR. CRANE: That is not only true with Franquettes but also with other varieties in California, even in Contra Costa County.
MR. STOKE: Where those trees are so grafted, does it tend to overgrow, or just the opposite?
DR. CRANE: No, it appears much like our Crenata-mollissima chestnut graft union failure.
MR. STOKE: Is there a tendency for the top to be more vigorous, to have more growth, or vice versa or is growth uniform?
DR. CRANE: It may be uniform. Depends somewhat on the varieties and the seedlings. There may be some overgrowth or some outgrowth, but there is only one test for it, and that is at the graft union. With an axe or knife and you cut out a strip of bark across the union. It may look absolutely perfect, but if there is a black line developed there that is just like a lead pencil line between the stock and the scion, the tree is on the way out. It's just a matter of time. Ultimately the bark between the stock and scion will split, and you get infolding, just like on the chestnut.
One of the reasons that they have propagated their trees on Northern California black walnut was that they had the idea that the Northern California produced a stronger, more vigorous seedling and that they grew much faster than seedlings of the Persian walnut. And, furthermore, somebody at some time circulated the idea that Northern California walnuts were immune to infection by the mushroom root rot fungus. We have surveyed thousands of trees of Persian on Persian roots, and we have never found a single case of black line developing or graft union failure as long as it's a Persian on Persian, and we find the same percentage of infection from mushroom root rot fungus on Persian as on Northern California black.
MR. CHASE: In other words, we should watch our stocks and perhaps try out some Regia on Regia?
DR. CRANE: That's right.
MR. CHASE: Now, folks, we could talk for a long time, but let me make one request before we close our panel: I would be interested in receiving from any member pictures, good, glossy photographs of the newer Carpathian varieties so that we can perhaps publish them in the newsletter and give some folks an opportunity to see what these nuts look like. Some of the folks who never come to a meeting never see a sample and just read about it. It's much better if we can show them a picture now and then. So if you have some good pictures, or plan to take some good pictures, remember, I'd like to have a copy.