MR. OAKES: I haven't.
MR. CHASE: No graft union failure on Regia and Nigra.
MR. STOKE: And my experience is they come in much quicker than on their own roots as seedlings.
DR. CRANE: How old are your oldest grafts?
MR. OAKES: Put on in 1938?
DR. CRANE: That's 15 years.
MR. STOKE: I have them at least 20 years.
MR. BECKER: Mine are twenty.
DR. MACDANIEL: Mr. Moderator, I have in my brief case a translation of the French book on walnut culture, and there is a section on root stocks. This was a publication issued about 1941, and according to that book, Juglans Nigra is the best stock they have for general use in France. They have reported no difficulty on this. A second one they were trying of the American walnuts, with some promise, was Juglans major, the Arizona black walnut.
DR. CRANE: The reason why I asked, as I reported in previous meetings—they are having very serious difficulty in Oregon and in parts of Washington with graft union trouble which is known as "black line." All or practically all of the walnuts in both Oregon and California and also what few are grown in Washington have been propagated on the Northern California black walnut, Juglans Hindsii. No graft union trouble evidence shows up before the tree has been grafted about 8 years, and then such cases are very rare. But after the trees or the grafts attain an age of 15 years or more, graft union failures are numerous. For three years now we have been making surveys in the State of Oregon, and we have surveyed tree by tree, year after year, the same orchards, the same trees, and our observations now go into the thousands, and we find that this black line is a terrifically serious thing. In some orchards 22 per cent of the trees will develop black line in one year's time. So, you see, at that rate it would only take you five or six years with a good bearing orchard until you wouldn't have any.