The genetic lottery: How grafting transformed the unreliable seedling into a commercial pecan crop

“ In the case of our native nuts the conditions are quite different. We know the original ancestor of the pecan, our hickories and our walnuts. The fine varieties now cultivated are not hybrids but have been selected from wild trees. In connection with nuts I would also point out that in all probability they were the most important food-staple of primitive man, as well as of his simian ancestors. It required no great intelligence to gather them or to store them after the fashion followed by squirrels. Intelligence, however, is required to plant nuts and to transplant nut trees. ”

“ The tree loves company or does well alone. When the hickory stands alone, the trees are well formed and make a good specimen tree. Many hickory trees are found growing in the river bottom land from Central to Southern Indiana with fewer trees found north of a line extending from Terre Haute through Indianapolis to Richmond. This southern area also contains the largest population of pecans. There are some woods that contain only pecan trees while a mile or so away no pecans are found but all are hickories and occasionally some woods contain both pecan and hickory. ”

“ We are blessed in our community with large numbers of native pecan seedlings. The behavior of different nuts on different stocks is not the same. Before any nut should be condemned we feel it should have an opportunity to perform on different stocks over a period of years. For this reason we always try to graft a number of trees to each variety.
Most things taken from nature are subject to improvement and can be better adapted to the use of man. I would like to see some new varieties of pecans developed for our northern zone. ”

“ Within the last ten or fifteen years it has rapidly emerged from a wild or semi-wild condition to the status of an orchard nut. The foundations of its culture were laid a considerable time ago, but only now is it coming to its own, its well merited standing among the fruits of the country.
In any horticultural industry many questions must be asked of the plant, the soil, the climate, in short, of the plant in its environment. They must be answered aright, if the industry is to succeed. The newer the plant in cultivation, the more numerous the questions are, the more difficult to answer. ”

“ However, there are hundreds of farmers today who would not undertake to raise pecans, for the reason that they think they cannot be transplanted. Also, in every community where the pecan is native, can be seen many seedling trees ranging anywhere from ten-to twenty-five years old that have never borne a nut. These trees are pointed out by the general public as horrible examples of the uselessness of attempted pecan culture. Near my home at Boonville, Ind., is a row of seedling pecan trees planted in a garden. ”

“ According to a census we have just completed there are in North Carolina upwards of 50,000 seedling pecan trees. These trees range in age from one to thirty years. Seventy-five per cent of them are of bearing age, but there is probably not one per cent of that number that are profitable bearing trees. In all parts of the pecan country experience has shown that seedling pecans are notably slow in coming into bearing and some trees never bear at all. Those that do bear have nuts that are almost invariably, small, thick-shelled and of indifferent quality. ”

“ The trees are now old enough to bear a half bushel of pecans every year, but so far as I know they have never borne a nut. The general public throughout the North and Middle West have not yet learned that the average seedling pecan is an uncertain quantity, grows slowly, bears irregularly, if at all, and probably inferior nuts. ”

“ In Posey County, Ind., near Evansville, are hundreds of wild pecan trees, many of which produce good nuts. One of them, from which I propagated last year under the name of the "Hoosier," is a very prolific tree. The nut itself is of medium size, beautiful color and thin shell, but the kernel qualities are not nearly so desirable as many of the other of our Indiana pecans, and it does not take a very high rank in the estimation of some of our observers. ”

“ In the ordinary course of events, with the exception of the pecan, years of experimentation in the testing of varieties and in a study of their cultural requirements must be gone through before any native species of nut-bearing trees can be planted in any of the northern states with a certainty of commercial return from nuts alone which would be comparable with that of many other crops which already are upon a well established commercial basis in this part of the country. ”

“ But if he is dissatisfied with a nut tree, it is his own fault if he does not change it. It can be top worked. He does not care to top work maples or oaks. We only top work to get something better than we have. The trees, of course, that interest us specially in top working are the nut trees. We have seedling pecans, seedling walnuts, seedling hickories, and seedling chestnuts. Down at the mouth of Green River in Kentucky are nearly two hundred acres of wild pecan trees. So far as we know there are only two trees in that orchard worthy of propagation. ”

“ 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. ”

“ Nut trees grown mainly for nut production rather than for timber may be planted 60 to 80 feet apart on the square plan.
The Thomas black walnut may bear a few nuts the second year following transplanting. Different varieties and species of grafted walnuts, pecans, and hickories often begin bearing from two to four years after setting. Chestnut seedlings may also bear in the second or third year. Black walnuts from seed sometimes bear a few nuts at 8 to 10 years of age. Profitable bearing, however, may not be expected in the average nut orchard until the trees are at least 10 to 12 years old. ”

“ 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. ”

“ Too commonly, transplanted nut trees suffer from sunscald injury on their southwest sides during the first summer in the orchard. This injury is particularly common on pecans, which suffer a severe shock from transplanting and are slow in re-establishing vigorous growth. In west Tennessee, as one grower puts it, "A pecan is doing well if it holds one green leaf its first year." Pecans have been known to remain dormant in their tops until the second spring after planting, and then start growth. ”

“ 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. ”

“ It will not do to mix together nuts of all sizes, shapes, and colors—some small, some large, some pointed, some blunt, some dark, some light, some streaked, and then expect to get the full value of the crop. ”

“ 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. ”

“ First, let me say that the principal point upon which we base our opinion that nut culture in the North has commercial possibilities, is the fact that growing throughout many sections of the North are thousands of nut trees, pecans, walnuts, hickories and butternuts, many of which grow very fine nuts. It would be a repudiation of all known laws of natural science to conclude that trees budded and grafted from these desirable parents would not grow and bear the same as they do. Therefore, we are perfectly safe in concluding that if there are successful nut trees growing, others also will grow. ”

“ 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. ”

“ Thanks to our pioneers of this generation who located some outstanding seedling pecans in the Ohio Valley, such trees as the original Major, Greenriver, and others have proved their worth as hardy northern pecans and they have been used for propagating purposes rather than being destroyed by farm hands who burned piles of debris left by high water around many of these early trees. ”

“ We also have many, many acres of nuts being propagated by topworking to varieties rather than by letting the seedling continue to produce. That is the reason why we are so much interested in getting a better type of pecan.
One man who makes it a commercial practice puts on thousands of scions every year. We in Oklahoma can't understand why you all seem to have so much trouble propagating nut trees. It is just as easy to propagate pecans and walnuts—not quite as easy—as apples, but then it isn't too difficult. ”

“ If properly cared for they will begin setting some nuts in a few years and will increase the crop as the years go by. A pecan tree ought to bear successfully for fifty years—possibly longer, and ought to be bearing nicely in eight years if properly cared for. But, success depends upon the care and intelligence with which the original selection of trees and soil is made, and upon proper cultivation. I have set an orchard of northern varieties of pecans budded from the parent trees in the Evansville section on my farm in Maryland this spring. The land cost me sixty dollars per acre. ”

“ 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. ”

“ If the trunks are straight and smooth, with bark uniform in appearance throughout, the trees have not been budded or grafted, unless the point of union is at the ground, and the trees having been grafted, and a terminal bud on graft has grown. If the young trees have been budded, the trunks will not be straight; a bend will be seen at the point where the bud was inserted (see Fig. 27) , and the scars of the union of the veneer-shield or annular bud and the point at which the stock was cut off will be distinctly noticeable. ”

“ Cut out and destroy, root and branch, those affected by rosette, those which are unhealthy, and top-work the remainder of those which do not produce a sufficient quantity of marketable nuts of good quality.
Top-working may be profitably applied to another class of trees—pecan trees in their native woods and thickets, and in some cases hickories, viz.: Hicoria tomentosa, H. alba, and H. aquatica, may be top-worked. ”

“ 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 ”

“ 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 [Pg 87] 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. ”

“ 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. ”

“ 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. ”

“ The number of varieties in the commercial orchard should not be large. No greater mistake can be made than that of planting a few trees each of a large number of different varieties. Four or five, at most, are sufficient; got fewer varieties, rather than more.
Trees can be purchased in two ways: They can be secured direct from the nurserymen (usually by catalogue) , or they can be purchased from agents. By far most of the pecan trees are bought from the nursery, and by many this method is preferred. ”

“ This is the ideal method of handling the crop, and the one method which enables the grower to secure the best price for his product.
In building up such a private trade, advertising must be resorted to, either through the newspapers, magazines and other channels, or by distributing samples of nuts. "Once a customer, always a customer" should be the motto for the grower to hold in mind, and every effort should be made and every precaution taken to see that the nuts, from year to year, are absolutely uniform in size, shape, and quality. ”

“ The preparation of the soil should be complete and thorough. It may be stated, as an axiomatic truth, that the soil cannot be prepared for trees as well after they are planted as it can before, and nothing is to be gained by planting the trees in poorly prepared land. Better by all means to spend a year or more in getting the land in shape.
If the land is covered with a growth of timber, this should be cleared away and the ground cultivated for a year at least before the trees are set. Corn is probably the best crop to grow on new land, and at the last working cowpeas should be sowed. ”

“ Planting Pecan Trees.
Too often but slight attention is given to this important piece of work. There is too frequently a disposition on the part of the person setting trees of any kind to do the work as rapidly as possible without consideration for the future welfare of the trees. Few realize that time spent in careful, intelligent preparation of the soil and in setting the trees is time well spent, and well paid for in the after development of trunk and branch. ”

“ For the growth of the young trees, a larger amount of nitrogen and a relatively smaller amount of phosphoric acid and potash are required, while for older trees, the reverse is true. Phosphoric acid and potash are required by bearing trees for the formation of fruit. Consequently, when the pecan orchard comes into bearing, these materials should be increased in the fertilizer applied. If the soil is not very rich at the time of planting, good results will follow the use of a pound of good commercial fertilizer at the time of planting. ”

“ The earth should be packed about the roots by hand, the tree being set no deeper than it stood in the nursery.
To start the trees off well, one pound to one pound and a half of a good fertilizer, analyzing about six per cent. potash, five per cent. phosphoric acid and four per cent. nitrogen, should be thoroughly mixed with the earth that is used in filling in the hole. Preferably, only surface soil should be used to place about the roots. ”

“ Shallow cultivation is all that is necessary after the first plowing. A weeder or light harrow will do the work. This shallow cultivation will preserve a dust mulch, a couple of inches or so in depth, and the loss of soil moisture by capillary action and evaporation will thereby be prevented; more moisture will be retained in the soil and the trees will be benefited accordingly.
Whether the orchard is planted in a crop or not, cultivation should begin about the time growth starts in spring. The ground should be plowed and leveled with a cultivator. ”

“ And when corn is grown, sow cowpeas at the last working of the crop, to enrich the soil. These legumes will add nitrogen to the soil and help to reduce the fertilizer bills, for nitrogen is the costliest of all the fertilizer materials which we buy.
Sometimes, it will not do to crop the orchard. A condition may have to be met, in which there is not enough water to supply both the trees and the growing crops and one or the other will suffer—the trees, usually. ”

“ But in growing a crop in the orchard, bear in mind that the trees [Pg 110] need, and are benefited by, cultivation, and that fertilizer will make them grow.
But, as already noted, humus is needed, and since this is the case, corn or cotton or clean-culture crops, which leave little behind them to make humus after they are removed, should not be grown every year. Some of the legumes should be brought in. Cowpeas, soja beans, beggarweed, velvet beans, alfalfa and melilotus can all be grown in the pecan area. ”

“ Pecan Scab (Fusicladium effusum) : This disease attacks the fruit, leaves and twigs. The husks of the diseased nuts become covered with dark spots or specks. They become hardened and crack open in places. As a result of the attack, growth is stopped, the fruit does not fill out and mature, but drops prematurely or, in some cases, remains attached to the trees long after the leaves have fallen. ”

“ As a general rule the burrows ascend the tree in a spiral about the trunk, so complete girdling is unusual, but [Pg 146] growth sometime ceases above the groove, new limbs being shot out from below."
The only satisfactory means of controlling this pest is to go carefully over the tree and dig out the borers. The trees should be examined from time to time in order to keep them free from borers.
Insects Attacking the Fruit.
The Pecan Weevil (Balantinus caryae) : In some localities considerable damage has been caused by the pecan weevil. ”

“ The growth of the tree is checked and these abnormal branches are formed only to die back each year. Trees in the earliest stages of rosette have been observed to have light crops of nuts, but, when badly diseased, are barren and unsightly or worse. Rosette has been found in all ages, from nursery stock to trees forty feet high. ”

“ After the harvesting of the crop the hogs should be allowed to feed under trees in which the weevil is present, so as to devour any infested nuts which may have been left on the ground. Poultry may also be of assistance in destroying the insects after they have entered the ground to pupate. ”

“ For all fungous diseases of the pecan which may be controlled by spraying no substance will give better results than Bordeaux mixture, and directions for preparing it are given at the end of this chapter. Paris green, at the rate of four ounces to each fifty gallons of liquid, may be added to the mixture for the destruction of biting insects. For effectual work in spraying large trees, a platform should be erected on the wagon-bed to make it possible to reach the tops with the spray. ”

“ The culture and care given other crops planted on it will be ideal for the pecans if fertilizer is used and leguminous crops for fallow are planted in proper rotation. Trees planted the usual distance of 50 to 60 feet apart each way, 17 or 12 trees to the acre, interfere very little with field work when they are young.
It is not believed that the demand for pecans will be met in a century. Americans are fast becoming a race of nut eaters. ”