The Pecan and its Culture Part 12

Small grains, oats, wheat, etc., should be rigidly excluded. When corn or cotton is planted, leave out a row or two of the crops where the tree row is. Let the trees have feeding s.p.a.ce, but cultivate all the ground.

If the season is dry, then give cultivation just as often as can be done. Every week or ten days, between the first of April and the first or middle of July, the ground should be stirred in young orchards.

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. After that, frequent shallow cultivation should be given with a light harrow or weeder. Once every week or ten days, if the weather is dry, will result in much good to the trees. If a shower should fall during one of these dry periods, the ground should be cultivated just as soon as it can be worked. A light harrow, which will break up the surface crust formed by the rain and leave instead a shallow mulch of pulverized soil, will go a long way toward conserving and holding the water which has been added by the recent rainfall.

The cultivation of old orchards may vary somewhat from that given younger ones. Some recommend that the old orchard be seeded to gra.s.s (Bermuda or Johnson gra.s.s) and used as a pasture. This may answer in some cases, particularly on very rich, alluvial soils, but, in general, it will not do as a definite policy year in and year out. Those orchards planted in gra.s.s which the author has had an opportunity to examine, have usually shown a large percentage of trees with branches dead at the tips, "stagheaded," with yellow leaves and a general appearance of unthriftiness. It may have been that these orchards were planted in gra.s.s while the trees were too young. The better treatment, and the safer one to follow in old orchards, is to cultivate the ground in spring and sow down in cowpeas or some other legume. Beggarweed, velvet beans or soja beans will answer well in many localities. Allow these to make what growth they will, and, when dead and dry, plow them back into the soil. It may seem strange to cultivate a forest tree, but it is the plan to follow to get results. Good results could doubtless be secured by seeding the pecan orchard in alfalfa and using it for a hog pasture up to the ripening season.

Cultivation should not be prolonged too late. If it be, the trees will continue to grow later than they should. Enough time will not be left in many sections before the coming of the first frosts. If the immature, sappy wood is caught by an early frost, severe injury may result. In the more southern extension of the pecan area cultivation can be carried on later than toward the northern limits of the region. Ordinarily, it is safest to cease cultivation not later than July the first to July the fifteenth.

FERTILIZATION.

On deep rich, alluvial soils the trees may not need to be fertilized, but many of the soils on which pecans have been set in orchard form, require to be fertilized to secure the best results. The three important plant foods required by plants and most frequently deficient in soils are nitrogen, phosphorus and potash. One or two or all three of these substances may have to be supplied.

Nitrogen, which is used by the trees largely in making growth of leaf and wood, may be supplied from a number of different sources, viz: stable manure, cotton seed, cotton-seed meal, dried blood, fish sc.r.a.p, sulphate of ammonia and nitrate of soda. These substances are the princ.i.p.al commercial sources of nitrogen. Large amounts of nitrogen are gathered by leguminous crops; cowpeas, vetch, beggarweed, velvet beans, alfalfa and others may be planted to advantage, resulting in a great saving in fertilizer bills, and besides, adding the necessary vegetable matter and humus.

The most common source of phosphorus, usually referred to as phosphoric acid, is acid phosphate. Some is obtained from bone, and bone meal is a good fertilizer to use among pecan trees. The results obtained from its use are not immediate, but since the bone does not decay rapidly, they extend over a considerable period. On the whole, acid phosphate is as satisfactory as any material as a source of phosphoric acid, and the goods with the highest percentage are usually the most economical in the end. A good grade is that a.n.a.lyzing fourteen per cent.

Potash may be purchased, as kainit, the raw salt, or as muriate of potash, low grade sulphate of potash and high grade sulphate of potash.

Of these the sulphates are usually given the preference in fruit growing. Of the domestic sources of potash, woodashes are important.

The amount of fertilizer which it is best to apply is difficult to decide upon; much depends on the character of the soil, what crops are cultivated and whether a crop of legumes is grown or not.

If legumes are grown for the benefit of the orchard, they should be fertilized, and if the crop is turned back into the soil, this may be sufficient for the trees, particularly while they are young. For the legumes, a good fertilizer to use per acre is:

Kainit, 100 lbs.; Acid Phosphate, 200 lbs.

or, High-Grade Sulphate of Potash, 50 lbs.

Acid Phosphate, 200 lbs.

In any case some allowance should be made for the amount of nitrogen collected by the legumes. When corn, cotton or some other crops are grown in the orchard, fertilizing may simply consist in distributing an additional amount of the crop fertilizer for the benefit of the trees.

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.

A good fertilizer for young trees should a.n.a.lyze five per cent.

phosphoric acid, six per cent. potash and four per cent. nitrogen. For bearing trees, one a.n.a.lyzing eight per cent. phosphoric acid, ten per cent. potash and four per cent. nitrogen will give good results. If so desired, well-known brands of commercial fertilizers, having approximately the above a.n.a.lysis, can be purchased in the markets, but if preferred, the several materials may be purchased separately, then mixed and applied.

APPLYING THE FERTILIZER.

The roots of young trees do not extend to any great distance away from the trunk. In distributing the fertilizer this fact should be remembered. A safe rule for all small-sized trees is to commence just outside an imaginary circle of two feet radius and apply the fertilizer in a circular band extending out some distance beyond the spread of the branches. Old trees, or those having a considerable spread of top, when planted in orchard form, should be fertilized by broadcasting the fertilizer over the ground. In the northerly pecan sections, all the fertilizer should be given in one application, about the time growth starts in spring, and plowed in, while farther south, two applications may be made, one at the time mentioned above, the other from the first to the middle of June.

CHAPTER XII.

PRUNING.

The pruning of the pecan is neither difficult nor complicated. In short, after the top of the tree is well started, little need be done except to cut back a branch here and there that the trees may develop well-rounded, symmetrical tops. A splendid type of tree is shown in Plate VI.

HIGH VS. LOW-HEADED TREES.

Frequently trees are so pruned that their first branches are eight or ten feet from the ground. Even young trees are pruned to slim stems, surmounted by a small umbrella-like top. Such trees frequently have to be tied to a post to keep them upright until such time as they attain sufficient size to support themselves. Such pruning should not be countenanced. The trees will make a much more rapid and satisfactory growth, and their trunks will be less affected by the hot sun, if the branches are allowed to develop lower down. Sometimes the system of pruning pecans with tall, bare trunks is adopted to allow of crops being grown under the trees, or because it is desired to use the ground as a cattle pasture. These considerations should not weigh against the welfare of the trees. As much ground can be cropped around low-headed trees as is good for them, and, in brief, the cows should be pastured elsewhere.

Ordinarily the top of the tree should be so shaped that the lower branches will be about four feet from the ground. The trunk will be shaded and protected, the crop will be nearer the ground, and the low tops will be less subject to the destructive force of heavy winds, so injurious to both fruit and branches.

To start the trees at four feet, the tops must be cut back to that height at the time the trees are set, or, if smaller, when they have grown to that height. Three or four buds nearest the top should then be allowed to develop and form the main framework of the tree. After this the trees will need little or no pruning, except the cutting back of straggling branches, and the removal of dead or broken ones.

Some writers have advised the persistent and severe cutting back of the tops, from time to time, so as to keep them small, compact and low, but such a system of pruning must be put into practice on a considerable scale for a number of years before it can be recommended. Such a plan might prove valuable where the trees are subject to the force of strong winds, but otherwise it is of doubtful value.

TIME TO PRUNE.

Pruning may be done at any convenient time, but the best period is probably either just before the flow of sap in spring, or just after the trees have fully developed their leaves in spring. Following the removal of branches of any considerable size--three-quarters of an inch and upward--the wounds should be carefully painted over with white lead paint to prevent decay.

CARE OF BROKEN TREES.

When trees are broken or injured by wind-storms, the broken branches should be cut off and the resulting wounds carefully trimmed and painted. If the branches are only partly split off, the injury may be repaired, in many cases, by pressing the branch back into place and bolting it there, so as to hold it firmly in place. Trees with forked trunks should be protected by pa.s.sing a bolt through the two branches some distance above where they divide to prevent splitting.

NURSERY ROOT-PRUNING.

Too frequently the root system of pecan trees, intended for planting, is but poorly developed. The root consists almost entirely of one large taproot dest.i.tute of laterals. Such trees are slow in starting and are hard to transplant. Figure 33 shows an excellent root system on a nursery tree. Such a tree should be almost as easily transplanted as an apple tree. A little more care on the part of nurserymen would insure good root systems.

In a former publication it was suggested that the young seedlings intended for stocks be root-pruned "in the fall, after the trees are one year old. It could easily be accomplished by running the tree-digger down the row at a depth of nine or ten inches. The taproots could thus be severed, and the following spring, or summer, the trees could be worked (budded or grafted). This course of treatment would insure greater success in transplanting, as it would have a tendency to develop the lateral roots; and in addition to that, it would, in all probability, induce earlier fruiting."

ROOT Tr.i.m.m.i.n.g BEFORE PLANTING.

Two year old taproots should be cut to eighteen or twenty-four inches; larger ones, in proportion. The old idea that transplanted pecan trees, the taproots of which have been cut back, will not live and bear, is not borne out by experience. They are in no-wise injured by its partial removal, and it might all be removed were it not that so many would die in transplanting.

[Ill.u.s.tration: FIG. 33. A nursery tree with a good root system.]

Figure 34 shows two pecan trees at two years. The one on the right was carefully lifted so as to preserve as much as possible of the taproot, while the one on the left had the taproot cut when it was transplanted at one year. In the latter, six small roots from four and one-half to eight inches in length had grown out to replace the taproot, these doubtless having supplied the tree with as much nourishment as would have been given by its single taproot. Furthermore, without doubt, one of these roots would have grown so as to replace the taproot.

The advice has been given to cut the taproots back to five or six inches, but under general average climatic conditions throughout the pecan region anyone who follows this advice will have reason to regret it. Our experience in transplanting pecan trees has been such as to indicate the necessity of having a well-branched, well-developed root system, and a taproot, when present, should be left at least as long as indicated above.

[Ill.u.s.tration: FIG. 34. a. Taproot cut at 1 yr. b. Taproot not cut.]

A long taproot is objectionable on account of the additional cost and labor entailed in digging holes of sufficient depth for planting. To shorten the length of the taproot, Mr. E. E. Risien, of San Saba, Tex., has patented a method which has given satisfactory results. The nuts from which the stocks are grown are planted over strips of mosquito netting, the netting being some distance below the level of the nuts.

When the taproots have penetrated to the netting, their growth is stopped, and the lateral roots develop better in consequence.