The crop, as with all orchard crops on the Pacific Coast, is cultivated intensively, clean tillage being given, followed by cover crops and in some cases fertilizers accompanied with intercrops.
The trees require very little pruning, and though formerly the heads were started high, they are now formed low and the primary branches trained to ascend obliquely, thus facilitating tillage operations, and, in this respect, even improving upon the high head with spreading or even drooping main branches. While the more progressive planters favor trees one year from the bud, which have been put upon two year old stock, some still prefer two year old tops. Stocks are preferably California black, northern form. This is a large and vigorous tree, while the southern form is often or perhaps better, usually, a large shrub or small tree.
The remarkable behavior of the Vrooman orchard at Santa Rosa, in which there are sixty acres of grafted Franquettes, has been the chief means of stimulating the very extensive plantings that have been made during the past five or six years in the Pacific Northwest. This is the largest orchard of grafted nuts of a single type variety in the United States and is a most excellent example of what follows grafting. The nuts are exceedingly uniform, and large size. They are marketed in the natural color and are especially attractive, particularly when of a reddish-golden tinge.
The trees begin to bear at five or six years, though many instances are recorded where two year olds have borne a few nuts. Usually only a few pounds per year are produced prior to twelve years, after that the yield increases rapidly until at sixteen years the trees will average approximately fifty pounds or more per tree under favorable soil, tillage, and climatic conditions, providing the trees are of selected varieties of good bearing qualities.
One tree, known as the Payne tree, top worked on to a native black, has a record of yielding as much as seven hundred and twelve pounds in one season, though it is not fair to use these figures in estimating the yield per acre of seventeen trees.
While the walnut has received little attention in the Eastern United States, there are sufficient data at hand now to warrant the statement that several meritorious varieties may be successfully grown in favorable localities. These nuts, though not rated as high as the best imported nuts or the choice California product, would successfully compete with the foreign nuts which are now rated as replacement nuts by the dealers in California's best grade. It is not safe to endorse the view that any waste or abandoned land may be converted into successful walnut orchards, though such lands may in due time produce trees that will bear nuts. A first-class walnut orchard can only be produced upon first-class land, deep, fertile soil, a low water table, an open subsoil, with choice varieties, grafted upon the most suitable stock and then given first-class tree-care.
Professor Lake: I think a man now is making a tremendous mistake who thinks for a moment of advising the planting of seedling walnuts. We are bound to meet the problem of grafted fruit right away. The success in grafting in Washington this year has been such as to make us feel certain that we may safely advise budding yearling stocks and expecting a return of from seventy to ninety per cent of successful sets. Stocks giving best success in budding are California black. About two weeks after the budding is done, the tops are cut off two inches above, and allowed to bend over and protect the buds; and in the West, where they have intense sunlight, they have found it necessary to cover the buds with paper sacks. The budding which has given the largest success is hinge budding, a kind that I haven't seen discussed generally in the East. Instead of being a T at one end, it is a T at both ends. There is a horizontal cut across, another below, and a split between. The buds are taken preferably from the last year's wood. We attempt to take the wood away from the bud, with the exception of that little spongy part that runs up into the bud, and is the core.
Mr. Pomeroy: You speak of the hulling. Do they have to hull the Persian walnuts?
Professor Lake: In many instances, especially in dry seasons, or in those sections where water is not particularly abundant. Ordinarily, hulling is avoided by irrigating just preceding the time of falling. Frequently the growers of large acreages say that it is cheaper to run them all through the huller.
Mr. Littlepage: What would you prophesy about the average seedling Persian walnut tree as to success and quality of nut?