The pecan tree is difficult of propagation by budding or grafting. Skillful propagators are satisfied with seventy-five per cent. of living buds or grafts, while very many have to be content with less. The difficulty is due, in part, to lack of skill; in part to lack of judgment in selecting good material with which to work; but in some regions it is due to the attacks of the bud-worm, Proteopteryx deludana, more than to anything else. The buds are eaten out and destroyed by this insect at the time they start into growth. In certain sections spring working of pecans has been abandoned entirely owing to the destruction wrought by this pest. But notwithstanding all the drawbacks, pecan trees can be, should be and are propagated in large numbers by budding and grafting, and the seedling is becoming more and more a thing of the past.

Seedling vs. Grafted Trees.

It is a fact worthy of note that the beginning of every tree-fruit industry is marked by the use of seedling trees. In the later stages of the development of the industry the seedling, owing to a more intimate knowledge of its failings and shortcomings, gives way to the grafted[I] tree. This stage has already been reached in pecan orcharding.

It has been stated that a certain percentage of pecans would produce nuts identical with those of the parent tree. The author has yet to find the first instance in which this was the case. This truth is borne out by the observations of others.

In view of the fact just stated, if a planter desires to secure a certain definite fixed variety of pecan, it can only be done by planting grafted trees. Even though all the seedlings were of good size, yet the variation in time of ripening, quality, prolificness, form and size would be against them. Take a certain quantity of each of a number of our largest pecans—Stuart, Van Deman, Centennial and Frotscher for instance—mix them together, and under average circumstances the mixed lot will sell for less money in the open market than the same varieties and the same nuts would if marketed separately. Mixed nuts, no matter how good the quality, cannot compete successfully in the market with a single uniform sample of the same or nearly the same quality.

Grafted trees will come into bearing at an earlier age than seedlings. In the case of seedlings it is very difficult to say when they will begin to bear, while grafted trees of the more precocious varieties may be expected to bear quite a little fruit in six or eight years from the time of planting.

The great objection to grafted trees is the first cost, and yet, in the face of that objection, it is best to plant grafted trees even if fewer of them are planted. If grafted trees are out of the question, then plant seedlings and top-work them. Grow the seedlings from nuts if necessary; but to those who live in sections where pecans can be grown, let me say, plant pecan trees; plant budded or grafted trees if you can—but plant pecan trees.

Pecan Stocks.

Nursery trees are propagated entirely on pecan stocks, and in the present state of our knowledge, it is the best stock to use. It may be that the pecan will grow and thrive as well on a number of different species of hickory, but definite information bearing on this point is lacking. Hicoria tomentosa, H. alba, and H. aquatica have been used for stocks in North Carolina, Florida, and other States, the pecan being top-worked upon them. But for the present, at least, until our experimental knowledge is farther advanced, the safest advice is to use pecan stock only.

Too little attention on the part of propagators has been given to the kind, source and quality of the seed used to raise stocks for propagation work. The main object held in view in making a selection for seed purposes is to get just as many nuts as possible in the pound. The result of this policy is, that, without question, inferior seedlings are often used for stock; they lack stamina and vigor. Frequently in a nursery of budded or grafted stocks, or in a young pecan orchard, a wide variation in the size and vigor of the trees can be noticed. No satisfactory explanation has ever been offered, but there seems little reason to doubt that it is due to the use of heterogenous lots of seed for stock purposes. The point must be emphasized, that greater care should be exercised in the selection of the seed used in nursery work. Nuts from rapid-growing, vigorous, healthy trees only should be used. It is best to plant in spring only nuts which matured the previous autumn. Preferably these nuts should be of fair or medium size for the variety to give the young seedling a fair start in life.

As already pointed out in regard to pecan shade trees for more northerly regions, so in the case of pecan nuts for use in raising stocks in northern sections. It is best to secure nuts from trees near the northern limits of nut production.

Storing and Planting Seed Nuts.

If pecan nuts, intended for seed purposes, are stored and kept as nuts ordinarily are kept, they become dried out. Before they will germinate the following spring they must absorb all the moisture lost and considerably more; in consequence of which they are slow in starting. If too thoroughly dried out, many may fail to germinate.

To obviate this, and to insure better and more prompt germination, it is best to keep the seed nuts in moist sand or clay during the winter months. Procure a sufficient number of shallow boxes or trays; three feet by one and a half feet by six or eight inches will answer nicely. These are to be used in stratifying the nuts. The earth to be used should preferably be good clean sand, free from organic matter, or, if this cannot be secured, clay will answer. Place a layer of the earth about one inch deep in the bottom of the boxes, then a single layer of nuts, then a two-inch layer of earth, and so on in alternating layers until the boxes are filled. These should then be slightly moistened and set aside in a sheltered place and covered with pine straw, leaves or straw.

In spring, when germination has just begun in the nuts and the tiny sprouts are beginning to appear, they should be planted in rows. The ground should be deeply plowed, well broken up, pulverized, and made moderately rich. Ground which produced a heavy crop of cowpeas, velvet beans or beggarweed the previous season is excellent for the purpose. Farm-yard manure, well decomposed and plowed in the autumn previous, is one of the best manures to use. The ground should be lined off in perfectly straight rows four feet apart, running east and west, that, the buds may be inserted on the north side. The nuts should be planted four or five inches deep, depending upon their size and the character of the soil. Large nuts should be planted deeper than small ones, and in heavy soils nuts may be planted somewhat nearer the surface than in light sandy ones. The rows may be opened with a small turning plow, or, for lesser areas, with a shovel. Place the nuts, a foot apart, carefully in the bottom of the furrow, cover with a hoe, roll the ground if the weather is dry, and then scarify the surface with a weeder or a light harrow to prevent evaporation of the soil moisture. Or the ground may be mulched with pine-straw, grass, leaves or other suitable material. If no mulch is applied, then the surface of the ground Should be cultivated shallow from time to time.

Some propagators have adopted the plan, with good results, of planting the nuts in the nursery rows, in late fall.

Cultivation of Nursery Seedlings.

From the time the young shoots begin to appear above the surface frequent shallow cultivation should be given. Once every ten days or two weeks is not too often, and the ground should be broken to a depth of one inch or so after every shower of rain. During dry weather more frequent cultivation, once every week, will be well repaid in the additional growth and vigor of the seedlings. A good commercial fertilizer, analyzing 5 per cent. phosphoric acid, 6 per cent. potash and 4 per cent. nitrogen, may be applied to advantage at the rate of fifteen hundred or two thousand pounds per acre. By the following autumn, the better seedlings will have ten or twelve inches of top, and two and a half or three feet of taproot. The following spring some may he whip-grafted at the crown, and by June, July and August of the same year many of them should have attained sufficient size for budding. Those which are not of sufficient size at this time can be worked the following spring and summer.

The Necessary Materials and Tools.

The materials and tools used in grafting and budding are: a grafting iron, a mallet, budding knives, grafting wax, strips of waxed cloth and twine.

Of grafting irons there are a number of different kinds, but one after the general type shown in Fig. 17, works very well. It will be noticed that the blade is curved at the corners, and the edge instead of being straight is curved downward in the center. This type of blade in some measure prevents the bruising of the bark when splitting the branch in cleft-grafting. Such a grafting iron may be made by almost any blacksmith. However, a good stout knife may be used instead.

For use in grafting, an ordinary budding knife, one of which is illustrated in Fig. 18, is well nigh indispensable. No other knife is so well adapted to making the smooth, sloping cuts on the scions.

Some persons can insert annular and veneer shield buds rapidly and well with nothing but an ordinary budding knife. In general, however, a budding knife having two blades, placed parallel with a space of three-quarters of an inch or an inch apart, is best. A very satisfactory knife may be made by fastening the blades of two ordinary budding knives on the sides of a piece of wood seven-eighths of an inch square and four inches in length. The blades can be firmly held in place by means of rivets and a piece of wire wound about the whole.

Three special budding knives, for use in pecan budding, have been introduced, one by Mr. Herbert C. White, of DeWitt, Ga., one by Mr. D. Galbreath, of New Orleans, La., and the other by Mr. Wm. Nelson, of New Orleans, La. In these knives the blades are fixed seven-eighths of an inch, one and one-eighth inch, and three-fourths of an inch apart, respectively. These make it possible to cut the buds and the place where they are to be inserted on the stock exactly the same size, an essential point in pecan budding. They have not yet come into general use, although well recommended by some who have used them. The White budding tool is particularly well adapted for use in top-working trees.

A good grafting wax may be made according to a number of different formulas. Either of the following will be found satisfactory:

Break the resin and cut the beeswax into small pieces. Place in an iron vessel, pour the oil over them and melt over a slow fire. Stir slightly to insure their being well mixed together, pour out into a bucket of cold water, grease the hands, and as soon as the mass is cool enough to handle, pull until it becomes light yellow in color. The wax may be made up in quantity and stored in greased tin or wooden boxes for future use.

To prepare waxed cloth, cut the cotton cloth into pieces of convenient size, say eighteen inches square, dip them down into the melted wax, remove them with a couple of sticks and stretch them out until cooled. For use, the cloth may be torn into strips of desired width and wound about a stick eighteen inches or so in length. Use a little grease to prevent the grafting wax and grafting cloth from sticking to the hands.

For waxed twine, procure No. 18 knitting cotton and drop the balls into the melted wax for a minute or two or until the wax penetrates them.

Selection of Scions.

Great care should be exercised in the selection of scions for use in budding and grafting. Much of the immediate success of the work depends upon the character of the scions, while the health and longevity of the future tree may be materially influenced by the kind of wood used in propagating work.

The practice of taking scions and buds from young trees which have never borne, or from nursery stuck, must be strongly condemned. They should be cut only from thrifty, vigorous, prolific trees. Even trees of the same variety differ in these things, and a thorough knowledge of what a tree will do and has done is the only true guide in the selection of scions. It is a well-known fact that desirable qualities can be reproduced and perpetuated by grafting.

Grafts should be selected from well-matured branches of one year's growth. Fig. 19, No. 1, shows an undesirable scion. The wood is angular, small, the internodes long, and the pith large in proportion to the diameter. Either terminal portions of twigs may be used or portions back of the tip, but the buds should always be well developed, full and plump—Fig. 19, Nos. 2 to 6. For this reason grafts should not be cut from wood far back from the tip of the branch. As stated, twigs of the previous season's growth are generally used, but scions composed partly of two-year-old wood may be used, provided the growth is not too large. Fig. 19, No. 3, shows one of these. Grafts are generally cut about five or six inches long, and should be from one-quarter to three-eighths of an inch in thickness.

It is best that the grafts be cut while still in a dormant state, and inserted in the stock just before the growth starts. The scions may be kept for a considerable length of time by placing them, loosely packed, in damp moss or sawdust, in a box. The box should be covered over with earth and the scions kept sufficiently moist to prevent drying out.

For bud sticks, well developed one-year-old branches, one-half to seven-eighths of an inch in diameter, and on which the buds are well formed, may be used. Such sticks frequently show three buds at a node, and if some misfortune should overtake one or two of these, there is still a chance of success, though the upper one being the strongest is generally the one which starts, provided it is uninjured and the bud takes. The degree of maturity of the bud is important, and care should be exercised that only those which are plump, full and well developed, are used. As soon as removed from the tree all bud sticks and grafts should be wrapped in damp newspapers to prevent drying out.

Time.

Grafts should be inserted in spring just before or at the time growth starts. Buds may be inserted any time during the period when the bark will slip readily. Last year's dormant buds may be inserted early in the season, or buds of the current season's growth may be used during the latter part of July and the month of August, at which time they have become fully matured in the southernmost parts of the Gulf States. The time may even be extended into September. Very many of these late-inserted buds remain dormant during winter and begin growth in spring.

Budding.

Annular Budding.—A ring of bark about one inch in length is removed from the stock. A bud stick of the same size is selected, and from it a similar ring with a good bud on it is removed by cutting around the bud stick and slitting down the back or side opposite the bud. This bud is then placed in position on the stock. After the buds are in place, a piece of stiff wrapping paper should be tied around the stock just above the bud and allowed to flare out over the bud to protect it from the sun and wind. Preferably all buds should be inserted on the north side.

Stocks from three-eighths to three-quarters of an inch may be worked by this method.

Veneer Shield-Budding. (Patch Budding). This method differs from the last only in that the piece of bark removed from the stock and the piece with the bud attached are not complete rings, but only parts. A rectangular or even a triangular piece of bark is taken out of the stock, a similar piece with a bud in its center taken from the bud stick is fitted in its place and wrapped in the usual way.

Mr. George W. Oliver, of the Bureau of Plant Industry, Washington, D. C., has described[J] a modified method of veneer shield-budding, which has given good satisfaction in his hands. Instead of removing the patch from the stock, it is slit down the center from top to bottom and the edges are lifted back, the buds inserted beneath and the side flaps are then tied down over it. He has also found that dormant buds of last year's growth give better results than buds of the current season.

The use of these buds has not, however, come into general use; first, because of the large amount of wood which must be destroyed to secure them; and second, because in those sections where bud-worms are prevalent, their larvÆ are to be found clustered about the buds until quite late in the season and make their attack as soon as the bud starts to grow.

Mr. E. W. Kirkpatrick,[K] McKinney, Texas, described a method successfully used by him, as follows:

Grafting.

Cleft Grafting. Having selected the branch for cleft grafting and the point at which the scions are to be inserted, the branch should be carefully and smoothly cut off. The limb is then split by using the grafting iron. If rapid work is to be done, grafts should be prepared beforehand and carried to the field, wrapped in damp paper. In preparing the scion, a sloping cut should be made about one and one-half inches long, cutting into the pith from a point one-half way up the cut down to the lower end. On the opposite side, the cut should not be made to touch the pith, but should be confined to woody tissue throughout its whole length. The knife should have a keen, sharp edge. The cut should be clean, smooth and straight, and the scion should be left wider on the outer side. Start the cuts on each side of, and just at a bud, as shown in Fig. 23. Having made the cleft, it is opened with the wedge on the end of the grafting iron and the scion is placed in position. The cambium layers should be in contact. Slip the scion well down until the whole of the cut surface is within the cleft. If the stock is large enough insert two scions. After inserting the scion it should be firmly held in place by binding the stocks with strips of waxed cloth, after which a covering of wax may be placed over the cloth. The cut end of the stock should be covered, and if the scion be other than a terminal shoot, its distal end should be waxed also.

Whip Grafting. Branches, which are to be worked by whip grafting, should be less than one inch in diameter. The method is illustrated in Fig. 24. A sloping cut, an inch and a half long, is made diagonally across the stock. A corresponding cut is made on the scion, a tongue is raised about the center of each cut by making another cut with the budding knife held almost parallel to the sides of the wood. The tongue is raised a little on both stock and scion and the two are shoved together. They should be securely bound with a strip of waxed cloth, and a layer of wax should be spread over the whole, covering up all the cut surfaces to the exclusion of water, air and the germs of decay.

The scion and stock are preferably chosen of nearly the same size, but a scion somewhat smaller than the stock may be used, in which case the cambium layers along one side of the surfaces in contact should be placed opposite each other, and the projecting portion of the stock trimmed off.

After-care.

In from ten days to three weeks, the buds should unite. They should be examined, and if union—indicated by the full, plump condition of the buds or the commencement of growth—has taken place, the wrappings should be removed. If growth has started, the stock should be cut off or lopped just above the insertion of the bud, in the case of budded trees. From time to time the trees should be examined, and all sprouts which might rob the bud of sap, thereby preventing its growth, should be rubbed off.