Again, seedling trees may be grown or purchased and set out in orchard form. When these have grown to an inch or so in diameter and have developed several branches, they may be top-worked. This method of securing a pecan orchard is somewhat slow, and is open to the objection that the buds or grafts frequently fail to take, and in consequence the task of top-working extends over a number of years, resulting in trees of irregular size and shape. But by this plan a planting of desirable varieties can be secured at little expense, and provided time is not a consideration, the plan will prove quite satisfactory indeed.
Methods of Operation.
It is best to insert both buds and grafts in parts having smooth bark, though grafts can be placed in rough barked parts as well. Frequently trees are in a very undesirable condition for top-working, and it should be borne in mind that those branches nearest the center of the tree will give the most satisfactory result in the rapid growth of buds inserted in them. If the tree is not in good shape for working—i. e., if no branches of desirable size and age are found in convenient places—the tree should be partially trimmed to a pollard, cutting some of the main branches back to stubs, and when shoots have started from these they may be grafted or budded. In from six to twelve months from the time buds have started from the branches thus cut back, under average conditions the new shoots will have grown to sufficient size to permit of their being budded or grafted. The best time to prune back trees to start new shoots for top-working is early in the month of March. In removing large branches there is always danger of splitting, because of the weight of the heavy branches. This may be entirely obviated by sawing upward from the under side of the branch as far as possible, then cutting from the upper side downward. A branch will split off and drop without injury to the remaining parts. All cut surfaces should be well covered with white lead paint to prevent decay.
The method of procedure depends upon the size and age of the tree and whether the tree is to be budded or grafted.
In top-working old trees, only a portion of the branches should be worked at one time. If the whole top be removed at once, the tree suffers a severe shock. Two or three years are necessary to top-work a large tree, a half or a third of the top being worked each year. If the trees are of small size, the whole top may be removed at one time.
Care of Top-Worked Trees.
For several months after the new top has commenced to grow, the scions have but a slight hold upon the stock. The leaf surface is often so large that a slight wind may twist them off. To prevent this, a number of branches may be tied together, or they may be fastened to stubs of branches left temporarily. Posts may be driven into the ground close to the growing scions, to which they may be tied. Use soft bandages and burlaps.
Plate VII.
An old Pecan tree Top-worked in the branches.