Every kind of budding is magical. Is it not wonderful to make a crab apple tree produce Stayman or Grimes Golden apples or a quince bush produce luscious Duchess pears? Is it not strange that the sap from the same root can produce red apples on one branch, yellow ones on another, and russets on a third? How does it come that one twig can be made to produce sour apples and the next Paradise Sweets? Strange! Wonderful!! but True!!! It is all owing to the fact that the sap of a tree is a homogeneous substance and that it is the bud through which it passes that stamps the individuality upon it whether it shall be a crab or a Grimes Golden. If we make all the buds of the tree of the Grimes character, the apples will all be Grimes Goldens. In the same way if we make all the buds on a pecan tree Stuarts or Schleys there will be nuts to be gathered from that tree and they will not be the worthless scrub seedlings.
When I began my experiments in the top-working of seedling pecan trees I soon found that there were many things one could not do with pecan trees. I counted myself a successful propagator of apples, peaches, plums, grapes and various other kinds of plants, but apple, peach and general propagation methods failed to give success in the budding and grafting of pecans. I concluded the method must be all right but that I should be more exact about my mechanical manipulations. I started out with the ordinary cleft graft commonly used for top-working most sorts of trees. I experimented in several different orchards and put in hundreds of cleft grafts. I took great pains to make my work as mechanically perfect as possible. All conditions of stock, scions, weather, etc., seemed to promise the highest degree of success. The result of that season's work was a world of disappointment, a lot of experience, and two living grafts. One of these latter, the result of my skill, was so effectively pruned that fall by the pecan girdler that my work for the season was a minus quantity in all but experience. The other living graft, which was put in by an assistant, is now a bearing Curtis tree, our only monument to the success of cleft grafting the pecan. Other propagators are said to be able to secure fair results with cleft grafting of pecans in certain localities, but from my experience, I am willing to aver that it cannot be done in this latitude.
Next followed a series of trials with shield budding which is so uniformly successful with peach, but peach methods failed entirely with pecans. Then followed a succession of trials with whip grafting, veneer grafting, bark grafting, and chip budding, all with a varyingly large percentage of failure and a uniformly small percentage of success. Some propagators in the South report fairly successful results in the chip budding of pecans, but my results with this method were largely of a negative character.
After persistent trials of all the known methods of budding and grafting, through the varying conditions of four successive seasons, I have narrowed the propagation of the pecan in North Carolina to one single method, namely, patch-budding. This method has year after year given us the highest percentage of successful unions. The operation illustrated by figures 1 to 12, is as follows:
1. Heading Back.
During the dormant period which is, roughly speaking, from November 1st to March 1st, the seedling trees are cut back to stubs, the ends of which may be from one to three inches in diameter. Wounds larger than this size take years to heal and endanger the life of the tree. Large trees can be operated on as well as small seedlings, only one has to go higher up so as not to cut too large limbs. Figure 1 shows a seedling pecan tree 18 inches in diameter, which was stubbed back in the winter of 1911-1912 and successfully budded the following summer. The result of this drastic heading-back is a numerous growth of vigorous, rapidly growing shoots near the ends of the stubs, by which Nature endeavors to heal over the wounds. The cambium in these vigorous, sappy shoots is in the most active condition possible; just the condition most suitable for the union of stock and scion. This optimum condition cannot be secured except by the forced growth as the result of the heading back. Our experiments, year after year, have shown that on the ordinary new shoots, even on active young seedling trees, the percentage of living buds was much less than on the forced shoots of the headed-back trees.
Fig. 1. Seedling pecan tree, 18 inches in diameter, cut back in winter, showing summer's growth of vigorous shoots ready for budding.
Fig. 2. First operation. Making parallel cuts on stock.]