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Cooeperative experiments.
"In order to secure information as to the behavior of fertilizers on the different soils of the Grape Belt, cooeperative tests were carried on in six vineyards owned, respectively, by S. S. Grandin, Westfield; Hon. C. M. Hamilton, State Line; James Lee, Brocton; H. S. Miner, Dunkirk; Miss Frances Jennings, Silver Creek; and J. T. Barnes, Prospect Station. The soil in these vineyards included gravelly loam, shale loam and clay loam, all in the Dunkirk series, and the experiments covered from two to two and a half acres in three cases and about five acres in each of the other vineyards. The work continued four years in all but one of the experiments, which it was necessary to end after the second year.
"The general plan of the tests was much like that at Fredonia in most of the vineyards, with the additions of plats for stable manure and for leguminous and non-leguminous cover crops with and without lime. From two to six check plats were left for comparison in each vineyard. As already stated the results were often inconsistent in duplicate plats in the same vineyard, and if one test appeared to point definitely in a certain direction, the indication would be negatived by results in other vineyards. In these experiments the yield of fruit was the only index to the effect of treatments as it was not possible to weigh leaves or pruned wood, or to count the canes left.
"Nitrogen and potassium in combination, which gave the largest gains and greatest profit in the Station vineyard at Fredonia, showed a 13 per ct. increase in yield on one plat in the Jennings vineyard and a 9 per ct. decrease on the other; in the Miner vineyard this combination apparently resulted in a 25 per ct. increase; in the Lee vineyard in a 2-1/2 per ct. loss; in the Hamilton vineyard a 17 per ct. gain; and in the Grandin vineyard neither gain nor loss. In only two of the five vineyards in which this combination was tested was the gain great enough to pay the cost of the fertilizer applied. Similar discrepancies, or absence of profitable gain, mark the use of the other fertilizer combinations.
"Even stable manure, the standby of the farmer and fruit-grower, when applied at the rate of five tons per acre each spring, and plowed in, did not, on the average, pay for itself. Indeed, there were few instances among the 60 comparisons possible, in which more than a very moderate profit could be credited to manure. The average increase in yield following the application of manure alone was less than a quarter of a ton of grapes to the acre; while the use of lime with the manure increased the gain to one-third of a ton per acre. The ton of lime to the acre annually would not be paid for by the gain of 175 pounds of grapes. Cover-crops were used in five of the six cooeperative experiments and proved even less adapted to increasing crop yields than did the manure. There was no appreciable gain, on the average, from the use of mammoth clover; indeed, a slight loss must be recorded for the clover except upon the plats which were also limed, and even with the lime the average yields on check plats and mammoth clover plats differed by only one one-hundredth of a ton. Wheat or barley with cow-horn turnips made a slightly better showing, as the plats on which these crops were turned under, without lime, averaged about one-twentieth of a ton to the acre better than the checks. With these non-legumes, lime was apparently a detriment, as the plants with the lime yielded a tenth of a ton less, on the average, than those without it."
Practical lessons from the Fredonia experiment.
From this experiment it becomes clear that the use of fertilizers in a vineyard is a local problem. General advice is of little value. It is evident also that the fertilization of vineyards is so involved with other factors that only carefully planned and long continued work will give reliable information as to the needs of vines. Indeed, field experiments even in carefully selected vineyards, as the cooeperative experiments show, may be so contradictory and misleading as to be worse than useless, if deductions are made from the results of a few seasons. The experiment, however, has brought forth information about fertilizing vineyards that ought to be most helpful to grape-growers. Thus, the results suggest:
Only vineyards in good condition respond to fertilizers.
It is usually waste to make applications of fertilizers in poorly drained vineyards, in such as suffer from winter cold or spring frosts, where insect pests are epidemic and uncontrolled or where good care is lacking. The experiments furnish several examples of inertness, ineffectiveness or failure to produce profit when the fertilizers were applied under any of the conditions named. They emphasize the importance of paying attention to all of the factors on which plant growth is dependent. Moisture, soil temperature, aeration, the texture of the soil, freedom from pests, cold and frosts, as well as the supply of food may limit the yield of grapes.
A vineyard soil may have a one-sided wear.
It is certain in some of the experiments and strongly indicated in others that the soil is having a one-sided wear—that only one or a very few of the elements of fertility are lacking. The element most frequently lacking is nitrogen. Exception will probably be found in very light sands or gravels which are often deficient in potash and the phosphates; or on soils so shallow or of such mechanical texture that the root range of the vine is limited; or in soils so wet or so dry as to limit the root range or prevent biological activities. These exceptions mean, as a rule, that the soils possessing the unfavorable qualities are unfitted for grape-growing. The grape-grower should try to discover which of the fertilizing elements his soil lacks and not waste by using elements not needed.
Grape soils are often uneven.
The marked unevenness of the soil in the seven vineyards in which these experiments were carried on, as indicated by the crops and the effects of the fertilizers, furnishes food for thought to grape-growers. Maximum profits cannot be approached in vineyards in which the soil is as uneven as in these, which were in every case selected because there was an appearance of uniformity. A problem before grape-growers is to make uniform all conditions in their vineyards, and the vines must be kept free from pests if fertilizers are to be profitably used.
How a grape-grower may know when his vines need fertilizers.
A grape-grower may assume that his vines do not need fertilizers if they are vigorous and making a fair annual growth. When the vineyard is found to be failing in vigor, the first step to be taken is to make sure that the drainage is good; the second step, to control insect and fungous pests; the third, to give tillage and good care; and the fourth step is to apply fertilizers if they be found necessary. Few vineyards will be found to require a complete fertilizer. What the special requirements of a vineyard are can be ascertained only by experiment and are probably not ascertainable by analyses of the soil. This experiment furnishes suggestions as to how the grape-grower may test the value of fertilizers in his own vineyard.
Applying fertilizers.
When it is certain that vines need fertilization, and what is wanted is known, the fertilizers should be put on in the spring and be worked in by the spring cultivation. Stable manure should be plowed under. Grape roots forage throughout the whole top layer of soil so that the land should be covered with the fertilizer, whether chemical or barnyard manure. Applications of commercial fertilizers are generally spread broadcast, though it is better to drill them in if the foliage is out on the vines and thus avoid possible injury to tender foliage. Commercial fertilizers should be mixed thoroughly and in a finely divided state. In leachy soils, nitrate of soda ought not to be applied too early in the season, as it will quickly wash down out of reach of the grape roots.
Over-rich soils.
Some soils are too rich for the grape. On these the growth is over-luxuriant, the wood does not mature in the autumn, fruit-buds do not form and the fruit is poor in quality. Certain varieties can stand a richer soil than others. Over-richness is a trouble that may cure itself as the vines come in full bearing and make greater demands on the soil for food. It is well, however, on a soil that is suspected of being too rich or so proved by the behavior of the vines, to provide an extra wire on the trellis, to prune little and thus take care of the rampant growth. Some soils, however, and this is often the case, are so rich that the grape cannot be made to thrive in them; the vines waste their substance in riotous living, producing luxuriant foliage and lusty wood but little or no fruit.
CHAPTER VII
PRUNING THE GRAPE IN EASTERN AMERICA
The inexperienced look on pruning as a difficult operation in grape-growing. But once a few fundamentals are grasped, grape-pruning is not difficult. There is much less perplexity in pruning the grape than in pruning tree-fruits. Pruning follows accepted patterns in every grape region, and when the pattern is learned the difficulties are easily overcome. The inexperienced are confused by the array of "principles," "types," "methods," "systems" and the many technical terms that enter into discussions of grape-pruning. Some of the technicalities come from European practices, and others originated in the infancy of grape-growing in this country when there was great diversity in pruning. Divested of much that is but jargon, an inexperienced man can easily learn in a few lessons, from word of mouth or printed page, how to prune grapes.
The simplicity of pruning has led to slighting the work in commercial vineyards, by too often trusting it to unskilled hands. Then, too, in this age of power-propelled tools, pride in hand labor has been left behind, and few grape-growers now take time and trouble to become expert in pruning. Simple as the work may seem to those long accustomed to it, he who wants to put into his pruning painstaking intelligence and to taste the joy of a task well done finds in this vineyard operation an ample field for pleasure and for the development of greater profits. The price to be paid by those who would thus attempt perfection in pruning the vine is forward vision, the mechanic's eye, the gardener's touch, patience, and pride in handicraft.
Simple as pruning is, the pruner soon learns that it is an art in which perfection is better known in mind than followed in deed. The theory is easy but there are some stumbling blocks to make its consummation difficult. It is an art in which rules do not suffice, for no two vineyards can be pruned alike in amount or method, and every grape-grower finds his vineyard a proper field for the gratification of his taste in pruning. Happily, however, enlightened theory and sound practice are in perfect accord in grape-pruning, so that specific advice is well founded on governing principles.
One cannot, of course, learn to prune unless he understands the habit of the grape-vine and is familiar with the terms applied to the different parts of the vine. As a preliminary to this chapter, therefore, knowledge of Chapter XVII, in which the structure of the grape-vine is discussed, is necessary. The next step is to distinguish between pruning and training.
PRUNING AND TRAINING DISTINGUISHED
The grape is pruned to increase in various ways the economic value of the plant by increasing the quantity and value of the crop. This is pruning proper. Or grapes are pruned to make well-proportioned plants with the parts so disposed that the vines are to the highest degree manageable in the vineyard. This is training. To repeat, the grape-plant is pruned to regulate the crop; it is trained to regulate the vine. Grape-growers usually speak of both operations as "pruning," but it is better to keep in mind the two conceptions. The distinctions between pruning and training must be made more apparent by setting forth in greater detail the results attained by the two operations.
Results attained in pruning to regulate the crop.
Proper pruning of vines in their first year in the vineyard, which, as we have seen, consists of cutting the young plants back severely, brings the vines in productive bearing a year or two years earlier than they would have borne had the pruning been neglected. This early pruning, since it is done with an eye to the vigor of each vine, insures greater uniformity in the growth and productiveness of the vineyard. Uniformity thus brought about is important not only for the time being, but for the future development of the vines, since weak vines, if unpruned, are stunted and may require years to overtake more vigorous vines in the vineyard.
The quality of the crop may be regulated by pruning. When vines bear too heavily, the grapes are small, and wine-makers have found that they seldom develop sugar and flavor as do grapes on vines not over-bearing. Grapes on vines too heavily laden seldom ripen or color well. Not only are the grapes on poorly pruned and unpruned vines poor in quality but the grapes on such vines are usually not well distributed and therefore ripen and color unevenly. The results just mentioned follow because the bunches in a poorly distributed crop receive varying amounts of light and heat depending on the distance from the ground, the distance from the trunk and on the amount of shade.
Pruning may be used to regulate the quantity of grapes borne in a vineyard and so be made somewhat helpful in preventing alternate bearing. Abnormally large crops are usually followed by partial crop failure and biennial bearing sometimes sets in, but the large crop may be reduced by pruning and the evil consequences wholly or partly avoided. It follows that pruning must depend much on the vigor of the vine; for a weak vine may be so pruned as to cause it to overbear; and, on the other hand, a vigorous vine pruned in the same way might not bear at all.
Results attained in pruning to regulate the vine.
It is necessary to regulate the shape of the vine by training so that tilling, spraying, pruning and harvesting can be easily performed and the crop be kept off the ground. The cost of production is always less in a well-pruned vineyard because all vineyard operations are more easily carried out.
The life of a vineyard is lengthened when the vines are well trained, because when the parts of a vine are properly disposed on trellis or stake the plants are less often injured in vineyard operations. Moreover, not infrequently vines die from over-production and consequent breaking of canes or trunks which might have been prevented by pruning to shape the vine. Suckers and water-sprouts are less common on well-trained vines. It is necessary, too, by training to keep the bunches away from trunk, canes and other bunches and so prevent injury to the grapes.
Lastly, fashion, taste or a more or less abnormal use of the grapes, may prescribe the form in which a vine is trained. Fashion and taste run from very simple or natural styles to exceedingly complex, formal ones, depending, often, on the variety, the environment or other condition, but just as often on the whim of the grape-grower. The grape is a favorite ornamental for fences, arbors and to cover buildings; for all of these purposes the vines must be trained as occasion calls.
SOME PRINCIPLES OF PRUNING
Leaving the shaping of the plant out of consideration and having in mind pruning proper, all efforts in pruning are directed toward two objects: (1) The production of leafy shoots to increase the vigor of the plant. (2) The promotion of the formation of fruit-buds. The first, in common parlance, is pruning for wood; the second, pruning for fruit.
Pruning for wood.
Some grapes, in common with varieties of all fruits, produce excessive crops of fruit so that the plants exhaust themselves, to their permanent injury and to the detriment of the crop. Something must be done to restore and increase vegetative vigor. The most natural procedure is to lessen the struggle for existence among the parts of the plant. The richer and the more abundant the supply of the food solution, the greater the vegetative activity, the larger the leaves and the larger and stouter the internodes. Obviously, the supply of food solution for each bud may be increased by decreasing the number of buds. The weaker the plants, therefore, the more the vine should be cut. The severe pruning in the first two years of the vine's existence is an example of pruning for wood. The vine is pruned for wood in the resting period between the fall of leaf and the swelling of buds the following spring.
Pruning for fruit.
Growers of all fruits soon learn that excessive vegetative vigor is not usually accompanied by fruitfulness. Too great vigor is indicated by long, leafy, unbranching shoots. Some fruit-growers go so far as to say that fruitfulness is inversely proportionate to vegetative vigor. There are several methods of diminishing the vigor of the vine; as, withholding water and fertilizers, stopping tillage, the method of training and by pruning. Pruning is used to decrease the vigor of the vine, in theory at least, for the practice is not always so successful, by pruning the roots or by summer-pruning the shoots.
Root-pruning the grape at intervals of several years is a regular practice with some varieties in warm countries, Europe more especially, but is seldom or never practiced in America except when planting and when roots arise from the cion above the union of stock and cion.
Summer-pruning to induce fruitfulness consists in removing new shoots with newly developed leaves. These young shoots have been developed from reserve material stored up the preceding season, and until they are so far developed that they can perform the functions of leaves they are to be counted as parasites. When, therefore, these shoots are pruned or pinched away, the plant is robbed of the material used by the lusty shoot which up to this time has given nothing in return. The vigor of the plant is thus checked and fruitfulness increased. Summer-pruning may become harmful if delayed too long. The time to prune is past with the grape when the leaves have passed from the light green color of new growth to the dark green of mature leaves.
Fruit-bearing may be augmented by bending, twisting or ringing the canes, since all of these operations diminish vegetative vigor. Ringing is the only one of these methods in general use, and this only for some special variety or special purpose, and usually with the result that the vigor of the vine is diminished too much for the good of the plant. Ringing is discussed more fully in Chapter XVI.
The manner of fruit-bearing in the grape.
Before attempting to prune, the pruner must understand precisely how the grape bears its crop. The fruit is borne near the base of the shoots of the current season, and the shoots are borne on the wood of the previous year's growth coming from a dormant bud. Here is manifested one of Nature's energy-saving devices, shoot, leaves, flowers and fruit spring in a short season from a single bud. In the light of this fact, pruning should be looked on as a simple problem to be solved mathematically and not as a puzzle to be untangled, as so many regard it. For an example, a problem in pruning is here stated and solved.
A thrifty grape-vine should yield, let us say, fifteen pounds of grapes, a fair average for the mainstay varieties. Each bunch will weigh from a quarter to a half pound. To produce fifteen pounds on a vine, therefore, will require from thirty to sixty bunches. As each shoot will bear two or three bunches, from fifteen to thirty buds must be left on the canes of the preceding year. These buds are selected in pruning on one or more canes distributed on one or two main stems in such manner as the pruner may choose, but usually in accordance with one or another of several well-developed methods of training. Pruning, then, consists in calculating the number of bunches and buds necessary and removing the remainder. In essence pruning is thinning.
Horizontal versus perpendicular canes.
An old dictum of viticulture is that the nearer the growing parts of the vine approach the perpendicular, the more vigorous the parts. The terminal buds, as every grape-grower knows, grow very rapidly and probably absorb, unless checked, more than their share of the energy of the vine. This tendency can be checked somewhat by removing the terminal buds, which also helps to keep the plants within manageable limits, but is better controlled by training the canes to horizontal positions. Grape canes are tied horizontally to wires to make the vines more manageable and to reduce their vigor and so induce fruitfulness; they are trained vertically to increase the vigor of the vine.
Winter-pruning.
Winter-pruning of the vineyard may be done at any time from the dropping of the leaves in the autumn to the swelling of the buds in the spring. The sap begins to circulate actively in the grape early in the spring, even to the extremities of the vine, and most grape-growers believe this sap to be a "vital stream" and that, if the vine is pruned during its flow, the plant will bleed to death. The vine, however, is at this season of so dropsical a constitution that the loss of sap is better denominated "weeping" than "bleeding." It is doubtful whether serious injury results from pruning after the sap begins to flow, but it is a safe practice to prune earlier and the work is certainly pleasanter. The vine should not be pruned when the wood is frozen, since at this time the canes are brittle and easily broken in handling. On the other hand, it is well to delay pruning in northern climates until after a heavy freeze in the autumn, to winterkill and wither immature wood so that it can be removed in pruning.
Summer-pruning.
There are three kinds of summer-pruning, the removal of superfluous shoots, heading-in canes to keep the vines in manageable limits and the pruning to induce fruitfulness discussed on a foregoing page, which need not have further consideration. It is very essential that the grower keep these three purposes in mind, especially as there is much dispute as to the necessity of two of these operations.
All agree that the vine usually bears superfluous shoots that should be removed. These are such as spring from small, weak buds or from buds on the arms and trunk of the vine. These shoots are useless, devitalize the vine, and hinder vineyard operations. A good practice is to rub off the buds from which these shoots grow as they are detected, but in most vineyards the vines must be gone over from time to time as the shoots appear. Still another kind of superfluous shoots, which ought to be removed as they appear, are those which grow from the base of the season's shoots, the so-called secondary or axillary shoots. These are usually "broken out" at the time the shoots from weak buds are removed.
While there is doubt as to the value of heading-back the vine in the summer for the sole purpose of inducing fruitfulness, there can be no doubt that it is desirable for the purpose of keeping some varieties within bounds. Heading-back is not now the major operation it once was, the need of severe cutting being obviated by putting the vines farther apart, by training high on three or even four wires and by adopting one of the drooping systems of training. The objections to heading-back in the summer are that it often unduly weakens the vines, that it may induce a growth of laterals which thicken the vines too much, and that it delays the maturing of the wood. These bad effects, however, can be overcome by pruning lightly and doing the work so late in the season that lateral growths will not start. Most vineyardists who keep their plantations up find it necessary to head back more or less, depending on the season and the variety. The work is usually done when the over-luxuriant shoots begin to touch the ground. The shoots are then topped off with a sickle, corn-cutter or similar tool.
RENEWING FRUITING WOOD
There are two ways of renewing the fruiting wood on a grape-vine, by canes and from spurs. The manner of renewing refers to pruning and not to training, for either can be used in any method of training.
Cane renewals.
Renewal by canes is made each year by taking one or more canes, cut to the desired number of buds, to supply bearing shoots. By this method the most of the bearing wood is removed each year, new canes taking the place of the old. These renewal canes may be taken either from the head of the vine or from the ground, though the latter is little used except where vines must be laid down for winter protection. Canes may be renewed indefinitely, if care is exercised in keeping the stubs short, without enlarging the head from which the canes are taken out of proportion to the size of the trunk. Renewing by canes is a more common method than renewal by spurs, as will be found in the discussion of methods of training.
Spur renewal.
In renewing by spurs, a permanent arm is established to right and left on the canes. Shoots on this arm are not permitted to remain as canes but are cut back to spurs in the dormant pruning. Two buds are left at this pruning, both of which will produce bearing shoots; the lower one, however, is not suffered to do so but is kept to furnish the spur for the next season. The shoot from the upper bud is cut away entirely. When this process is carried on from year to year, the spurs become longer and longer until they become unwieldy. Occasionally, however, happy chance permits the selection of a shoot on the old wood for a new spur. Failing in this, a new arm must be laid down and the spurring goes on as before. The objections to renewing by spurs are: it is often difficult to replace spurs with new wood, and the bearing portion of the vine gets farther and farther from the trunk. For these reasons, spur-renewing is generally in disfavor with commercial grape-growers, though it is still used in one or two prominent methods of training, as will be discovered in this discussion. Figure 13 shows a vine ready for pruning.
THE WORK OF PRUNING
The pruner may take his choice between several styles of hand pruning-shears with which to do his work. The knife is seldom used except in summer-pruning, and here, more often, the shoots are broken out or pinched out. In winter-pruning, the cane is cut an inch or thereabout beyond the last bud it is desired to leave; otherwise the bud may die from the drying out of the cane. The canes are usually allowed to remain tied to the wires until the pruning is done, though growers who use the Kniffin method of training may cut them loose before they prune. Two men working together do the work of pruning best. The more skilled of the two severs the wood from the bearing vine, leaving just the number of buds desired for the next season's crop. The less skilled man cuts tendrils and severs the cut canes from each other so that the prunings may be moved from the vineyard without trouble by the "stripper."
Not the least of the tasks of pruning is "stripping" the brush and getting it out of the vineyard. The prunings cling to the trellis with considerable tenacity and must be pulled loose with a peculiar jerk, learned by practice, and placed on the ground between the rows. Stripping is done, usually by cheap labor, at any time after the pruning until spring, but must not be delayed until growth starts or the young buds may suffer as the cut wood is torn from the trellis. The brush is hauled to the end of the row by hand or by horse-power applied to any one of a dozen devices used in the several grape regions. One of the best is the device in common use in the Chautauqua vineyards of western New York. A pole, twelve feet long, four inches in diameter at the butt and two at the top, is bored with an inch hole four feet from the butt. A horse is hitched to this pole by a rope drawn through the hole, and the pole, butt to the ground, is then pulled between rows, the small end being held in the right hand. The pole, when skillfully used, collects the brush, which is dumped at the end of the row by letting the small end fly over towards the horse. The "go-devil," shown in Fig. 14, is another common device for collecting prunings.
THE TRELLIS
The trellis is a considerable item in the grape-grower's budget, since it must be renewed every fifteen years or thereabouts. Wires are strung in the North at the end of the second season after planting, but in the South the growth is often so great that the wires must be put up at the end of the first season. Trellises are of the same general style for commercial vineyards; namely, two or three wires tautly stretched on firmly set posts. Occasionally slat trellises are put up in gardens but these are not to be recommended for any but ornamental purposes.
Posts.
Strong, durable posts of chestnut, locust, cedar, oak or reenforced cement are placed at such distance apart that two or three vines can be set between each two posts. The distance apart depends on the distance between vines, although the tendency now is to have three vines between two posts. The posts are from six to eight feet in length, the heaviest being used as end posts. In hard stony soils it may be necessary to set the end posts with a spade, but usually sharpened posts can be driven into holes made with a crowbar. In driving, the operator stands on a wagon hauled by a horse and uses a ten- or twelve-pound maul. The posts are driven to a depth of eighteen or twenty-four inches for the end posts. However set, the posts must stand firm to hold the load of vines and fruit. The end posts must be braced. As good a brace as any is made from a four-by-four timber, notched to fit the post halfway up from the ground, and extending obliquely to the ground, where it is held by a four-by-four stake. A two-wire trellis and a common method of bracing end posts are shown in Fig. 15. The posts on hillsides must lean slightly up-hill, otherwise they will almost certainly sooner or later tilt down the slope. The posts are usually permitted to stand a little higher at first than necessary so that they may be driven down should occasion call; driving is usually done in the early spring.
Wire for the trellis.
Four sizes of wire are in common use for vineyard trellises; nos. 9, 10, 11 and 12. Number 9, the heaviest, is often used for the top wire with lighter wires lower. The following figures show the length of wire in a ton:
No. 9, 34,483 ft. No. 10, 41,408 ft. No. 11, 52,352 ft. No. 12, 68,493 ft.
From these figures the number of pounds required to the acre is easily calculated. Common annealed wire makes a durable trellis, but many growers prefer the more durable galvanized wire, the cost of which is slightly greater. The wires are fastened to the end posts by winding once around the post, and then each wire is firmly looped about itself; they are secured to the intervening posts by ordinary fence staples so driven that the wire cannot pull through of its own weight but with space enough to permit tightening from season to season. The size and length of the staples depend on whether the posts are hard or soft wood. The longest and largest staples are used with soft woods, as cedar or chestnut. An acre requires from nine to twelve pounds of staples. The wires should be placed on the windward sides of posts and on the up-hill side in hillside vineyards. The distance between wires depends on the method of pruning.
The wires must be stretched taut on the posts, for which purpose any one of a half-dozen good wire stretchers may be purchased at hardware stores. Some growers loosen the wires after harvest to allow for the contraction in cold weather and others use some one of several devices to relieve the strain. Most growers, however, find it necessary to go over the vineyard each spring to drive down loosened posts and stretch sagging wires, and so take no precautions to release wires in the fall. All agree that the wires must be kept tight during the growing season to protect buds, foliage and fruit from being injured from whipping.
Tying.
The canes are tied to the trellis in early spring, and under most systems of pruning the growing shoots are tied in the summer. This work is done by cheap men, women, boys and girls. A great variety of material is used to make the tie, as raffia, wooltwine, willow, inner bark of the linden or basswood, green rye straw, corn husks, carpet-rags and wire. The same materials are not usually employed for both canes and shoots, since the canes are tied firmly to hold them steady and the work is done early before there is danger of breaking swelling buds, while the summer shoots are tied to hold for a shorter time and more loosely to permit growth in diameter. Tying usually follows accepted patterns in one region but varies greatly in different regions. There is a knack to be learned in the use of each one of the materials named, but with none is it difficult, and an ingenious person can easily contrive a tie of his own to suit fancy or conditions.
CHAPTER VIII
METHODS OF TRAINING GRAPES IN EASTERN AMERICA
The grape-grower takes great liberties with Nature in training his plants. No other fruit is so completely transformed by the grower's art from its natural habit of growth. Happily, the grape endures cutting well, and the pruner may rest assured that he may work his will in pruning his vines, following to his heart's desire a favorite method with little fear of seriously injuring his vines. Because of its accommodation to the desires of man in the disposition of the vine, there are many methods of training the grape; there being in the commercial vineyards of eastern America a dozen or more. However, the differences and similarities are so marked that the several methods fall into a simple classification which makes conspicuous their chief features. Thus, all of the methods fall under two chief heads: (1) The disposition of shoots; (2) the disposition of canes.
The disposition of shoots.
Bearing shoots are disposed of in three ways in training grapes; shoots upright, shoots drooping, and shoots horizontal. The terms explain themselves, but the three methods need amplification since their adoption is not optional with growers but depends on several circumstances.
Shoots are trained upright in several methods in which two or more arms or canes are laid to right and left, sometimes horizontally, sometimes obliquely along or across horizontal wires. As the shoots grow upward, they are tied to wires above. The upright methods are supposed to distribute the bearing wood more evenly on the vines and to insure greater uniformity in the fruit. In the upright methods, also, the canes and arms are left nearer the ground, which is thought to be an advantage in small, weak or slow-growing varieties. Delaware, Catawba, Iona and Diana are examples of varieties thought to grow best when trained to one of the upright methods.
In the several methods in which the shoots droop, however the canes may be disposed, the shoots are not tied but are allowed to droop at will. These methods are comparatively new but are being rapidly adopted because of several marked advantages. Usually one less wire can be used in a drooping method than in an upright one; since the shoots are not tied, much labor is saved in summer tying; the ground can be tilled with less danger to the vines; and there is less sun-scalding of the fruit, since the pendant foliage protects the clusters. Grape-growers generally agree that strong-growing varieties like Concord, Niagara, Brighton, Diamond and most of the hybrids between European grapes and native species grow best when the shoots droop.
Shoots are trained horizontally in but one recognized method, the Hudson Horizontal, to be described in detail later. Since this method is all but obsolete, there is still less reason for discussing it here, the expressive name sufficing for present purposes.
Disposition of canes.
There are many recognized methods of disposing of the canes in training the grape. The chief of these are discussed in the pages that follow, their names being set down for the present in the classification that follows.
CLASSIFICATION OF METHODS OF TRAINING THE GRAPE IN EASTERN AMERICA
I. Shoots upright:
1. Chautauqua Arm. 2. Keuka High Renewal. 3. Fan.
II. Shoots drooping:
1. Single-stem, Four-cane Kniffin. 2. Two-stem, Four-cane Kniffin. 3. Umbrella Kniffin. 4. Y-stem Kniffin. 5. Munson.
III. Shoots horizontal:
1. Hudson Horizontal.
I. Shoots upright
Systematic training of the grape in America began toward the middle of the nineteenth century with a method in which the shoots were trained upright from two permanent horizontal arms. These arms are laid to right and left on a low wire and bear more or less permanent spurs, from each of which two shoots are produced each season to bear the crop. The number of spurs left on each arm depends on the vigor of the vine and the space between vines. As the shoots grow upward, they are tied to upper wires, there being three wires on the trellis for this method. This method is now known as the Horizontal Arm Spur. It has a serious fault in its troublesome spurs and has almost entirely given way to a modification called the Chautauqua Arm method, much used in the great Chautauqua grape-belt. As one of the chief methods of training the grape in eastern America, this must be described in detail.
The Chautauqua Arm method.
The trellis for this method has two wires, although occasionally three are used. The lower wire is eighteen or twenty inches above the ground and the second thirty-four inches above the lower. If three are used, the wires are twenty inches apart. F. E. Gladwin, in charge of the vineyard laboratory of the New York Agricultural Experiment Station at Fredonia, in the heart of the Chautauqua belt, describes this method of training as follows:
"The vines are cut back to two buds at each pruning the first two years. If the vines are vigorous two canes are tied up at the beginning of the third year; if scant, but one is left and this, if the growth is extremely unfavorable, is cut back to two buds. The canes are carried up obliquely to the upper wire when the growth permits and are there firmly tied either with twine or fine wire, the latter being more commonly used. The canes are also loosely tied to the lower wire. The pruning for the fourth year consists in cutting away all but two or three canes and a number of spurs from the arms formed by tying up the two canes the previous year. The vine now consists of two arms, arising from near the ground, with two or three canes of the previous year, and several two-bud spurs at intervals along the arms. As far as possible such canes as have arisen but a short distance above the lower wire are selected. All the old wood projecting beyond the last cane retained on each of the arms is cut away. The arms of the third year are bent down from their oblique position and are tied firmly to the lower wire, to the right and left of the center of the vine. These are now permanent arms. The vine at this time consists of two arms, arising from near the ground, tied to the lower wire to the right and left of the center, and on these are two or three canes, pruned long enough to reach to the middle wire at least, and if possible to the upper. They are tied so that they stand in a vertical or oblique position. Along the arms at intervals of a few inches are spurs, consisting of two buds. If the vineyardist maintains the arms permanently, these spurs furnish the fruiting wood for the succeeding year.
"At the pruning for the fifth year one of the arms is cut away entirely, close to the point of its origin. The remaining arm, reaching from the ground to a point a few inches below the level of the lower wire, now becomes the permanent stem. The vineyardist must now provide for the arm cut away. This is done by the selection of a cane, arising from the remaining arm at a point below the lower wire, either directly, or from a spur left for the purpose. This is pruned to reach the top wire and is tied obliquely to it. This cane at the next pruning is tied down to the lower wire and becomes the second arm. Then the same selection of canes and spurs is made from it as was made at the previous pruning, and the canes are tied up as before. However, if the grower desires to retain both arms of the preceding year for a few years, canes that have grown from the spurs may be tied up and provision made for the following year through further spurring. If but a single arm is retained, it is pruned in the same way. Spurs may be obtained from canes that have arisen from dormant buds on the arm, or by spurring in the basal canes of the fruiting wood of the year previous. A combination of both methods of renewal will in the long run work out the better, as the repeated spurring in of the basal canes will result in greatly lengthened spurs that will require frequent cutting out. While the canes that arise directly from dormant buds on wood two years and over are not necessarily the best fruiting ones, they can, however, be utilized for renewal purposes.
"The ideal vine pruned to this system now consists of a stem reaching from sixteen or eighteen inches above the ground level or a few inches below the level of the lower wire. Such a vine is shown in Figure 16. From the head two arms arise, one extending to the right, the other to the left and tied along the lower wire, each arm not extending for more than two feet and a half to either side of the head. From the arms two canes on each are tied vertically or obliquely to the top wire. In addition there are left two or three spurs, growing from the upper side of each arm, located at well-spaced intervals starting close to the head; these may be used for the renewal of the arms. The shoots are not tied.
"One of the chief faults of the Chautauqua Arm method is the tendency of the best matured, and most desirable canes to develop at or near the upper wire, while those lower down are often too short, or so poorly matured as to be unfitted for fruiting purposes. When the wood, bearing the well-developed upper canes, is brought down for arms, a considerable interval of the arm from the head to the point where the canes arise is without fruiting wood. Under such conditions the growth will be again thrown to the extremities. If spurring on the arms has been practiced, this undesirable condition is eliminated. With either type of renewal, spurring should be practiced. The fruit from vines trained by this method reaches its highest development at or near the level of the upper wire, that on the lower shoots is, as a rule, quite inferior. This comes from the fact that the sap flow is more vigorous at these upper points, resulting in more and healthier leaves, which, in turn, influence the fruit for the better."
Keuka High Renewal.
Several methods of training pass under the general term "High Renewal," the significance of which becomes apparent in the discussion of the Keuka High Renewal method which is probably now the most common of the several types. In most of these methods the trellis is put up with three wires, but occasionally only two wires are used and still less often four. The lowest wire on the three-wire trellis is eighteen or twenty inches from the ground with twenty-inch intervals between wires. Gladwin, who has direct charge of vineyard experimental work about Keuka Lake for the New York Agricultural Experiment Station, describes current practices in pruning according to this method as follows:
"At each pruning for the first two years the vines are cut back to two buds. However, with strong-growing varieties like Concord, Niagara and Isabella, and under good soil conditions, the stem may be formed the second year. With moderate-growing varieties and under average conditions, the formation of the stem is left until the third year. The straightest and best-matured cane is left for the purpose. This is carried to the lower wire and there firmly tied with willow. As soon as the shoots have made sufficient growth they are loosely tied to the wires that they may be kept away from the tillage tools. The fourth year the head of the vine is formed. This should stand a few inches below the lower wire. Two canes growing from the stem near this position are selected, one being tied to the right and the other to the left along the lower wire. In the Keuka Lake District, the canes are tied with willows. In addition, at least two spurs of two buds each are retained near the head. With Concord, the canes may carry about ten buds each, but with Catawba, as grown on the hillsides of the Central Lakes Region of New York, the canes should not carry above six buds each. As the shoots develop from the horizontal canes, they are tied with rye straw to the middle and upper wires. This summer tying is almost continuous after the shoots are long enough to reach the middle wire.
"The following year all the wood is cut away except two or three canes that have developed from the basal buds of the canes put up the previous year, or that have grown from the spurs. In the event of a third cane being retained, it is tied along the middle wire. Spurs are again maintained close to the head for renewal purposes. The other two canes are tied along the lower wire as before. If the same spurs are used for a few years they become so long that the canes arising from them reach above the wire and cannot be well managed in the 'willowing.' It is desirable to provide new spurs annually, selecting those canes for the purpose that arise from the head of the vine or near it. It is possible by careful pruning to so cut away the old wood that practically all that remains after each pruning is the stem. Thus the vine is renewed almost to the ground. When the stem approaches the end of its usefulness, a shoot is allowed to grow from the ground, and the old one is cut away. Figure 17 shows a vine pruned by the Keuka method.
"This method of training is especially well adapted to slow growing varieties, or those situated on poor soils, where but little wood growth is made. It is ideally adapted for the growing of Catawba on the hillsides of Keuka Lake. It is well adapted to late-maturing varieties planted out of their zone. Concord, growing under average conditions, is too vigorous to be trained by this method. It makes a tremendous growth of wood out of all proportion to the quantity of fruit, which is inclined to be very inferior. The chief objection to this method is the amount of summer tying involved which comes at a time when attention to tillage should be given. It might prove profitable in the growing of dessert varieties that have been discarded because of lack of vigor. On thin hillside soils, Catawba requires training modelled after this method but on the heavier upland ones, with shorter pruning, it can be grown on the Chautauqua Arm plan. Delaware, Iona, Dutchess, Campbell, Eumelan, Jessica, Vergennes and Regal are, as a rule, grown to better advantage when trained by the High Renewal method."
Fan-training.
The only other method now in use in which the shoots may be trained upright is that in which the canes are disposed of in fan-shape. This method was much used a generation ago but is rapidly becoming obsolete. In fan-training the renewals are made yearly from spurs near the ground, and the fruiting canes are carried up obliquely and so form a fan. The great advantage in fan-training is that a trunk is almost dispensed with, which greatly facilitates laying down the vine in winter where winter-protection is needed. There are several objections to this method in commercial plantations. The chief one is that the spurs become long, crooked and almost unmanageable so that renewals from the root must be made frequently. Another is that the fruit is borne close to the ground and becomes soiled with mud in dashing rains. The vines, also, are inconvenient in shape for tying. There are two or three modifications of fan-training which may be described as mongrel methods between this and the High Renewal and Horizontal Arm methods, none of which, however, is now in general favor.
II. Shoots drooping
Quite by accident, William Kniffin, a stone mason living at Clintondale, New York, in the Hudson River grape region, discovered that grapes of large size and handsome appearance could be grown on vines in which the canes were trained horizontally with the shoots drooping. He put his discovery in practice and from it have come the several methods of training grapes which bear his name. Kniffin's discovery was made about 1850 and the merits of his methods spread so rapidly over eastern America that by the end of the century the various Kniffin methods were more generally used than any others. Grape-growers now agree that strong-growing vines like Concord, Niagara and Clinton are best trained to one or another of the Kniffin methods. There are several modifications of Kniffin's method, three of which are now in common use, the most popular being the Single-stem, Four-cane Kniffin.
The trellis for the three methods carries two wires, the lower placed at the height of three to three and a half feet and the upper from two to two and a half feet above it. To permit this height of wires, the posts must be from eight to eight and a half feet in length, and must be firmly set with the end posts well braced.
Single-stem, Four-cane Kniffin.
As practiced at the New York Agricultural Experiment Station, the vines are trained as follows:
One trunk is carried to the top wire the third year after planting, or if the growth is not long enough at this time, it is carried to the lower wire and there tied. In this case, the following year a cane is extended to the top wire. This trunk is permanent. If the stem reaches the upper wire the third year, growers break out many of the developing shoots and allow only the strongest to grow, choosing those that arise close to the wires. The stem should be tied tightly to the top wire and somewhat loosely to the lower. If girdling results at the top, it is not objectionable as the head of the vine should be below rather than above the wire. When the shoots are sufficiently hardened, those growing close to the wires should be loosely tied to prevent injury during cultivation. At the beginning of the fourth year, as shown in Fig. 18, the vine should consist of a stem extending from the ground to a point below the top wire. From this, all but two canes and two spurs of two buds each have been cut away below each wire level. As growth is most vigorous at the top of the stem, four to six more buds are left on the upper than on the lower canes. A vine of which the stem reaches the upper wire the third year should support the next season canes, aggregating twenty-two buds with eight additional buds on the spurs. If the growth is weak, only half this number should be left.
The tying at this time consists of fastening the stem loosely, with ordinary grape twine, to the lower wire, and with the same material the canes are tied along the two wires to right and left of the stem. The canes should be tied tightly toward the trunk so that they cannot slip out of the twine. Ordinarily tying at this time is sufficient for the year, but if conditions for growth are unfavorable, the twine may rot before the tendrils take hold of the wires, and a partial second tying may be necessary.
After the fourth season, the pruner has greater choice of fruiting-wood for the following year. It may be chosen from the basal canes of the preceding year's wood or the canes that develop from the spurs may be used. The choice should depend on the accessibility and maturity of the wood. At each pruning, the possibilities for obtaining fruiting wood for the following year must receive consideration. It is possible to use the same spurs for two or three years, but after this they should be cut away and new ones retained. After the first spurring, spurs should be selected from wood older than two years. The shoots from such wood bear but little fruit and hence make good fruiting canes for the next year.
Umbrella Kniffin.
Since most of the fruit on vines trained by the Four-cane Kniffin method is borne on the two upper canes, some growers in the Hudson River Valley dispense with the lower canes and cut the upper ones long enough to bear the crop. In this method the trunk is brought to the top wire and the head formed as in the Four-cane Kniffin. When the vines are pruned at the close of the third year, two long canes are left at the head of the vine with two renewal spurs. These long canes are drooped over the upper wire obliquely down to the lower wire to which they are tied just above the last bud, forming an umbrella-shaped top as shown in Fig. 19. The renewals are made as in the Four-cane Kniffin. This method reduces the amount of leaf surface to the minimum, so that care must be taken to insure healthy leaf growth. The amount of fruiting-wood put up is also reduced to the minimum, so that the yield is low unless good cultivation is provided, in which case, with some varieties and on some soils, the yield is up to the average and the crop is first-class as regards size of bunch and berry, compactness of bunch and maturity.
The Two-trunk Kniffin.
The Two-trunk Kniffin, illustrated in Fig. 20, is another modification with the aim of securing greater fruitfulness. This method also provides an equal number of buds on both wires. Two trunks are brought from the root, one to the upper, the other to the lower wire. The fruiting canes are taken off and are disposed of as in the Four-cane Kniffin. The trunks are usually tied together to hold them in place. This method is in restricted use in the Hudson River Valley where it is known under the name given here and as "Double Kniffin" and "Improved Kniffin." In experiments in training grapes at Fredonia, New York, under the direction of the New York Experiment Station, this method proves to be one of the poorest in growing Concords. The grapes fall short in size of bunch and berry and do not mature as well as under the other drooping methods of training.
The Y-trunk Kniffin.
Still another modification of the Kniffin method is one in which a crotch or Y is made in the trunk midway between the ground and the lower wire. The theory on which this method is founded is that sap for the lower canes is better supplied than in a straight or continuous trunk and that the lower canes thus become as productive as those on the upper wire. The theory is probably wrong but is accepted by many notwithstanding. The methods of pruning, renewing fruiting-wood and tying are the same as in the Single-stem Kniffin, except, of course, that each stem supports two canes and two spurs. This method was in somewhat common use some years ago in parts of western New York but is now disappearing.
The Munson method.
An ingenious modification of the Kniffin principle was devised by Elbert Wakeman, Oyster Bay, Long Island, and afterwards improved and brought into prominence by the late T. V. Munson of Denison, Texas; it is now much used in southern vineyards. The method is described as follows by Munson:[14]
"The posts should be of some durable strong wood, such as Bois d'Arc (Osage), Cedar, heartwood of Catalpa, Black Locust or White Oak. The end posts of every row should be large and strong and be set three and one-half or four feet in the ground and well tamped. The intermediate posts, which may be much lighter than the end posts, should be six and one-half or seven feet long and set two to two and one-half feet in the ground, with twenty-four feet spaces between posts, which will take three vines, eight feet apart, or two vines twelve feet apart. After the posts are set, a three-eighths-inch hole should be bored through each post, four feet from the surface of the ground, in the direction in which the row runs, leaving six inches or more of post above the hole. These holes are for the admittance of the middle, lower wire of the trellis.
"For each end post prepare for cross-arm, a piece of two by four hard pine or oak, two feet long, and at one inch from either end, and one inch from the upper side, bore a three-eighths of an inch bit-hole, or saw into upper side half an inch, which will take less time and do as well, to pass the lateral wires through, and in the middle of the lower side, saw a notch one-half inch deep. For each intermediate post, prepare a board of similar wood, two feet long, one inch thick by four broad, and likewise bore or notch.
"Through the holes in the posts run a No. 11 galvanized wire, fasten at one end, tighten at the other end by a wire stretcher and fasten. This will be the middle and lower wire of the trellis, and all that will be needed the first year, when the young vines are trained up a string, tied from the vine (when set) to the wire, and along it. The arms, and the two lateral wires which they bear, need not be put on the trellis until after the vines are pruned and tied the next winter. To put on the cross-arms, use no bolts or nails, only No. 11 galvanized wire.
"Each end cross-arm is placed inside the post, and against it on top of the wire, already through the posts, notch-side downward, straddling the wire, to keep it from sliding. Then take a piece of same size wire, about seven feet long, pass one end through the bit-hole or saw-notch, in one end of arm and fasten it by looping and twisting about six inches of the end back upon itself, then while one person holds the cross-arm in place, the operator carries the wire down around the post once near the ground, staples it on each side and brings the other end up to the opposite end of arm, puts it through the bit-hole, or saw-notch, draws it tightly, keeping the arm level, and fastens the end of the wire as was done the other. Wire nippers and pliers will be needed for this work. Then take another piece of wire about two feet long, and put it twice around the cross-arm and the post where they come together, above the middle wire, and firmly tie them together, crossing the wire as it goes around. This will hold the arm in place and not weaken or split the arm as do nails and bolts, and will be longer-lasting, quicker and cheaper, and more elastic, so that when struck by the hames or collar in cultivation, it gives a little, receiving no damage.
"Likewise place the cross-arms on the intermediate posts, leaving the ends of the wire projecting about six inches after fastening, for a purpose soon to be mentioned. Then draw the two lateral wires through the bit-holes in the ends of the arms, or drop into the saw-notches, if such are made, throughout the row, tighten with the wire stretcher and fasten. Then return along each lateral wire, wrapping ends of wire at the ends of the arms very closely and tightly around the through-going lateral wires, as telegraph and telephone wires are wrapped in splicing. This is quickly done with the proper pliers, and prevents the arms from slipping out of proper position. Now the trellis is complete, and will need little or no repairs, and looks very neat, especially if painted.
"Pruning and training on the Munson trellis is very simple and easy with a little instruction for a few minutes with a vine or two pruned for example. The vine the first season is allowed to grow up on to the middle wire by a string around which it is coiled by hand, by going over the vineyard once or twice until the selected shoot of each vine is upon the wire, after which it is allowed to ramble at freedom over the wires. By getting on to the trellis the first year, one strong shoot, and allowing no other to grow, a partial crop can be had the second year, without damage, on all but weak growers, like Delaware, that should not be allowed to bear until the third year. At the first regular pruning (all prunings should be done in November or December, after leaf fall, and never so late as to cause the vines to bleed), the vine should be cut back to two or three buds that have reached the middle wire, if weak growers, if strong, with heavy growth, six or eight buds each, to two arms, one going each way along the lower wire from where the ascending vine first touches the wire. After the vines are thus pruned, the outer end of each arm is firmly tied to the lower wire, along which it is gently coiled. These two ties hold the vine firmly in place. The buds on the arms push and ascend, passing over the lateral wires, clinging thereto with their tendrils, and hang over like a beautiful green drapery shading the fruit and body of the vine according to its natural habit.
"On the canopy trellis, all the summer pruning required is, to go through the vineyard at or a few days before blooming time, and with a light sharp butcher knife, clip off the tips of all advanced shoots to be left for bearing, leaving two or three leaves beyond the outer flower cluster. From the shoots near the crotch, selected for bearing arms the next year, pick the flower clusters, and strip off or rub off all shoots and buds that start on trunk of vine below crotch. This latter is very important, as such shoots, if left, eat up the nourishment of the land with no return but added work at pruning time.
"It will be found that the shoots at the ends of the arms usually start first and strongest, and if not clipped back, will not allow the buds back toward the crotch to start well, but if clipped, all other desirable buds then push.
"In about six to ten days after the first clipping, a second one is usually necessary, especially if the weather is moist and warm, and the land rich. The first clipped shoots, as well as those not clipped the first time, will need clipping back this time, the end buds on the first clipped having pushed vigorously.
"At a second year's pruning and others following, the old arms with all the bearing shoots on them are cut off down to the new arms and the new arms cut back to lengths they can fill with fruit and well mature. In this, critical judgment and knowledge of capabilities of different varieties are more required in the pruner than in any other of the training work. Some varieties, such as the Delaware, cannot carry more than three to four arms, two feet long, while Herbemont can more easily carry four arms each eight feet long, hence such as Delaware should be planted eight feet or less apart, while Herbemont and most of the Post-Oak grape hybrids, should be twelve to sixteen feet apart. In other words, each variety should be set that distance apart that it will fill the trellis with fruit from end to end, and mature it well, so as to better economize space.
"By the third year, the vine should come to full bearing, and be pruned with four bearing arms, two to go each way along the lower wire of trellis, gently coiling around the wire, one arm in one direction, the other in opposite direction, and should be in about equal lengths, so that one firm tie with jute yarn, near the ends, will be all the tying the vines will need—that is, two ties to each vine—the least required by any trellis system, and the pruning is also simplest and the results every way the best.
"Some of the advantages of this trellis are its cheapness, its simplicity, bringing the work up breast-high so that pruning, tying, harvesting, spraying, can be done in an erect position, saving back strain; perfect distribution of light, heat and air to foliage and fruit; shielding from sunscald and birds; giving free ventilation and easy passage of wind through the vineyard without blowing down the trellis or tender shoots from the vines, and allowing ready passage from row to row, without going around, thus getting larger and better crops at less expense and increasing length of life of vineyard and the pleasure of taking care of it."
This method does not seem to be adapted to the needs of grapes in northern vineyards, and in the South such weak-growing sorts as Delaware do not thrive when so trained. Several "modified Munson methods" are in use in the southern states, but those most commonly employed do not depart greatly from the method here described.
III. Shoots horizontal
Hudson horizontal.
There is now in use but one method of training shoots horizontally. In this method the trellis is made by setting posts eight or ten feet apart and connecting them by two slats, one at the top of the posts, the other about eighteen inches from the ground. Strands of wire are stretched perpendicularly between the slats at ten- or twelve-inch intervals. One cane is trained from a trunk from one to two feet high on the trellis; it rises perpendicularly from the ground and is tied to the top slat. The shoots push out right and left and are tied horizontally to each wire as they reach it. The cane is usually allowed to bear about six shoots on each side. The grapes set at the base of the shoots so that the bunches hang one over the other, making a pretty sight. This method is too expensive for a commercial vineyard but is often used in gardens and for ornamental plantings. Only weak-growing sorts, as Delaware, Iona or Diana are adapted for this method. Delaware does remarkably well under horizontal training. The use of slats and wires in horizontal training are often reversed. The alternative from the method just described is to set posts sixteen or eighteen feet apart upon which are strung two wires as for the ordinary trellis. Perpendicular slats are then fastened to these wires to which the shoots are tied. Two slats, fifteen inches apart, are provided on each side of a fruiting cane, which, with the slat for the support of the cane, give five to a vine. Or the vine may be supported by a stake driven in the ground.
In both of these methods, a shoot must be taken out from the head of the vine each season for the next season's fruiting-wood. This shoot is tied to the central wire or slat and is now allowed to fruit. Thus the vine starts each spring with a single cane. Grapes are grown under these horizontal methods chiefly, if not only, in the Hudson River Valley and even here they are going out of use.
TRAINING ON ARBORS, PERGOLAS AND AS ORNAMENTALS
The grape is much used to cover arbors, pergolas, lattices and to screen the sides of buildings, few climbing plants being more ornamental. Leaf, fruit and vine have been favorite subjects for reproduction by ornamentalists of all ages. As yet, however, it is seldom seen in cultivated landscapes except to secure shade and seclusion.
Grown for aesthetic purposes, the grape is seldom fruitful, for the vines can rarely be cultivated or deprived of their luxuriant growth as in the vineyard. Nevertheless, grapes grown as ornamentals can be trained so as to serve the double purpose of ornamental and fruit-bearing plant. Grown on the sides of a building, the grape often can be made to bear large crops of choicely fine fruit. The ancients had learned this, for the Psalmist says: "Thy wife shall be like the fruitful vine by the sides of thine house."
In all ornamental plantings on arbors or pergolas, if fruit is to be considered, the permanent trunk is carried to the top of the structure. Along this trunk, at intervals of eighteen inches, spurs are left from which to renew the wood from year to year. The vines should stand six or eight feet apart, depending on the variety, and one cane is left, three or four feet long, on each spur when the pruning is done. Shoots springing from these cover intermediate spaces soon after growth begins. Provision, of course, must be made for a new cane each season, and this is done by saving a shoot springing from spur or trunk at pruning time.
The same method of training, with modifications to suit the case, may be employed on sides of buildings, walls, fences and lattices. If the object to be covered is low, however, and especially if fruit as well as a covering is wanted, perhaps a better plan is annually to renew from a low trunk or even back to the root. In this low renewal, a new cane, or two or three if desired, should be brought out each season, thus securing greater vigor for the vine, but greatly delaying, especially in the case of high walls, the production of a screen of foliage.
PRUNING AND TRAINING MUSCADINE GRAPES
The Muscadine grapes of the South are so distinct in characters of growth and fruit-bearing that their requirements as to pruning and training are quite different from the methods so far given. Until recent years when these grapes have become of commercial importance, it was thought by southern vineyardists that the Muscadines needed little or no pruning and some held that pruning injured the vines. Now it is found that Muscadines respond quite as readily as other types of grapes to pruning and training. Husmann and Dearing[15] give following directions for pruning Muscadines:
"Two systems of training are employed with Muscadine grapes: (1) The horizontal or overhead system, by which the growth is spread as an overhead canopy about 7 feet above the ground and supported by posts; and (2) the upright or vertical system, in which the growth is spread over a trellis.
"In the overhead system a single trunk is caused to grow erect from the ground alongside a permanent post. When the vine has reached the top of the post it is pinched in or cut back, so as to make it throw out shoots to grow and spread out from the head of the vine as the spokes of a wheel radiate from the hub. (The overhead training of Muscadines is shown in Fig. 21; upright training, in Fig. 22.)
"In the upright systems the fruiting arms are either radiated from a low vine head, like the ribs of a fan, or they are taken off as horizontal arms from a central vertical trunk.
"Where the vineyard is not given close personal attention and pruning and other vineyard practices are neglected the best results will be obtained with the overhead trellis. Moreover, such a trellis permits cross-plowing and cultivation and is better adapted for grazing hogs, sheep, or cattle on cover crops grown in the vineyard. On the other hand, the careful vineyardist can expect the best and earliest results from vines on the upright or vertical supports. The upright trellis facilitates pruning, harvesting, spraying, and intercropping throughout the life of the vineyard; it is also easier to repair and can be erected from $10 to $20 an acre cheaper than the overhead trellis. The use of both the upright system and the overhead trellis has netted the growers profitable returns. Each has its advantages and disadvantages. The prospective grower, knowing his own conditions, must determine which training system is best suited to his conditions.
"During the first year after planting, a strong stake reaching 4 feet above the ground at each vine is sufficient support. A trellis should be erected the second season, though the upper wires of an upright trellis and the secondary wires of an overhead trellis may be added later, as the vines need them. In erecting an upright trellis the posts should be set midway between the vines, the distances apart varying with the distances between the plants. The end posts of the rows should be firmly braced. Three wires are generally used, placed 24, 42, and from 56 to 60 inches from the ground.
"In erecting an overhead trellis, the usual method is to place a substantial, durable post reaching 7 feet above the ground at each of the permanent vines. Rows of extra heavy, well-braced posts, running parallel with and also at the ends of the rows of vines, are set at the boundaries of the vineyard. There are a number of different ways of arranging the wires. Usually No. 10 galvanized wires are securely fastened to the tops of the boundary posts on the four sides of a vineyard and then are run along and securely fastened on the tops of the inside post down each row in both directions as governor wires. As needed, No. 14 wires 2 feet apart are run parallel with the governor wires until in this manner the entire area has been covered.
"A cheaper but less durable overhead trellis is made by running No. 9 governor wires in only one direction and the secondary wires only at right angles to the governor wires, the secondary wires being fastened to the governor wires wherever they cross.
"Some growers construct arbors entirely of wood, using slats or poles instead of wires.
"The pruning of Muscadine grapes during the first three years is mainly for the purpose of establishing the permanent parts and adjusting the other parts of the vine to the desired training system for future usefulness. After that the pruning is primarily a matter of renewing the bearing surface and keeping the vines healthy, vigorous, and productive.
"During the first season the trunk of the vine should be established. From this the main fruiting branches are started the second season. These, under favorable circumstances, will bear a small crop of fruit the third season. After that the purpose of pruning should be to renew growth, to increase or decrease the bearing surface, and to maintain the shape of the vine.
"Severe pruning usually removes most of the fruit-bearing wood and throws the vine into vigorous wood growth. No pruning, on the other hand, causes a growth which is too much distributed, weak, and incapable of bearing good crops. Therefore, the grape grower should study the vines sufficiently to enable him to judge each year the proper severity of pruning for the best results. This will depend on the variety, the age of the vines, the fertility of the soil, etc. Muscadine grapes bear their fruit in small clusters. It is therefore necessary to maintain a large fruiting surface in order to secure a proper tonnage of fruit. This is accomplished by developing a series of fruiting arms, spurring along these, and lengthening them as the vines become stronger. Such fruiting arms can be maintained for a number of years, but after a time it is desirable to renew them. This is done by cutting out the arm and starting a new one from a cane that has been previously grown for such purposes. It is preferable to renew systematically only one or, at most, two arms on a vine each year. This gradual renewal does not disturb the vigor of the vine, but keeps it productive, healthy, and strong. The pruning can be quickly and easily done if systematically practiced from the time the vines are started."
REJUVENATING OLD VINES
When pruning and training are neglected, a vineyard soon becomes a sorry company of halt and maimed vines. These neglected vines can rarely be reshaped and restored to their pristine vigor. If the old vines seem capable of throwing out a strong new growth, it is almost always better to grow a new top by taking out canes from the roots and so rejuvenate. The energy and activity of Nature are seldom seen to better advantage than in these new tops, if the old tops are cut back severely and the vineyard given good care. The new canes grow with the gusto of the biblical bay tree, making it difficult oftentimes to keep them within bounds.
Usually this new top can be treated essentially as if it were a new vine. Not infrequently the cane will make sufficient growth and mature well enough so that it may be left as a permanent trunk at the end of the first season. If, however, the wood is short, weak and soft, it should be cut back in the autumn to two or three buds from one of which a permanent trunk can be trained the next season from which a good top can be formed in another season. The old top is discarded as soon as the new trunk is tied to the trellis. Old vineyards are often rejuvenated in this way to advantage and return profits to their owners for years; but if the soil is poor and the vines weak, attempts to renew the tops seldom pay.
Occasionally rejuvenating old vines by pruning is worth while. When such an attempt is made, it is best to cut back severely at the winter-pruning, leaving two, three or four canes, depending on the method of training, of six, eight or ten buds. The amount of wood left must depend on the vigor of the plant and the variety. The success of such rejuvenation depends much on selecting suitable places on the old vine from which to renew the bearing wood. It requires good judgment, considerable skill and much experience to rejuvenate successfully an old vineyard by remodeling the existing top, and if the vines are far gone with neglect it is seldom worth while.
Sometimes old vines or even a whole vineyard can be rejuvenated most easily by grafting. This is particularly true when the vines are not of the kind wanted, and when the vineyard contains an occasional stray vine from the variety to which it is planted. Directions for grafting are given on pages 45 to 50. The grafted vine is readily brought into shape, under any of the several methods of training, by treating it as a young vine.
CHAPTER IX
GRAPE-PRUNING ON THE PACIFIC SLOPE
The methods of pruning and training native grapes, discussed in the last two chapters, do not apply to the Vinifera grapes grown in the favored valleys of the Rocky Mountains and on the Pacific slope. As we have already seen, the Vinifera or Old World grape differs markedly in habits of growth from the American species so that it would not be expected that pruning which applies to the one would apply to the other types. The fundamentals, to be sure, are much the same and the different species of grapes are about equally subservient to the shears of the pruner, but while pruning to regulate fruit-bearing finds many similarities in Old and New World grapes, the training of the vines is radically different.
European practices in pruning and training Vinifera grapes are so many and so diverse that the first growers of this fruit in America were at a loss to know how to prune their vines. But, out of a half century of experience, American growers of Old World grapes have adapted from European practices and have devised to meet new conditions, methods which serve very well in the new home for this old grape. Since the culture of the Old World grape is centered in California, almost confined to that state, California practice may be taken as a pattern in pruning and training the vines of this species.
VINE PRUNING IN CALIFORNIA[16]
The systems of pruning in use in California may be divided into two classes according to the arrangement of the arms on the trunk of the vine. In the commonest systems, there is a definite head to the trunk, from which all the arms arise symmetrically at nearly the same level. The vines of these systems may be called "headed vines." In the other systems, the trunk is elongated four to eight feet and the arms are distributed regularly along the whole or the greater portion of its length. The vines of these systems, owing to the rope-like form of the trunks, are called "cordons."
The headed vines are divided according to the length of the vertical trunk into high, 2-3 feet, medium, 1-1-1/2 feet, and low, 0-6 inches. The cordons may be vertical or horizontal, according to the direction of the trunk, which is from four to eight feet long. The horizontal cordons may be single (unilateral) or composed of two branches extending in opposite directions (bilateral). Double and even multiple vertical cordons occur, but they are very inadvisable and have no advantages.
The arrangement of the arms of a headed vine may be symmetrical in all directions at an angle of about 45 degrees. Such a vine is said to be "vase-formed," though the hollow center which this term implies is not essential. This is the form used in the great majority of our vineyards whether of wine, raisin, or shipping grapes. It is suitable for the "square" system of planting and cross cultivation. Where vines are planted in the avenue system, particularly when trellised and where cross cultivation is impossible, the arms are given a "fan-shaped" arrangement in a vertical plane. This arrangement is considered to be essential for the economical and easy working of trellised vines.
On the vertical or upright cordon, the arms are arranged at as regular intervals as possible on all sides of the trunk from the top to within twelve or fifteen inches of the bottom. On the horizontal cordon the arms are arranged similarly, but as nearly as possible on the upper side of the trunk only.
Each of these systems may again be divided into two subsystems, according to the management of the annual growth or canes. In one, spurs of one, two, or three eyes are left for fruit production. This system is called short or spur pruning. In the other, long canes are left for fruit production. This is called long or cane pruning. In rare cases an intermediate form is adopted in which long spurs or short canes of five or six eyes are left. In cane pruning, each fruit cane is accompanied by one or two short renewal spurs. These must also accompany half-long pruning. Systems of pruning, when only long canes are left without renewal-spurs, are not in use in California. In all systems, replacing-spurs are left wherever and whenever needed.
Other modifications are introduced by the manner of disposal of the fruit canes. These may be tied up vertically to a stake driven at the foot of each vine or bowed in a circle and tied to this same stake, or they may be tied laterally to wires stretching along the rows in a horizontal, ascending or descending direction.
The different systems differ therefore in: (1) the shape, length, and direction of the trunk; (2) the arrangement of the arms; (3) the use of fruit spurs or fruit canes with renewal spurs; (4) the disposal of the fruit canes.
The principal possibilities of the pruning are shown in the following table:
A. HEAD PRUNING: VASE-FORM
} { (a) Fruit spurs or } { 1. High trunk: } { (b) Half-long canes and renewal } { spurs or 2. Medium trunk: } with { } { (c) Fruit canes and renewal 3. Low trunk: } { spurs; canes vertical } { or bowed.
B. HEAD PRUNING: FAN-SHAPED; TRELLISED
1. High trunk: Fruit canes and renewal spurs; canes descending.
2. Medium trunk: Fruit canes and renewal spurs; canes horizontal or ascending.
C. CORDON PRUNING
1. Vertical: Spur; half-long; cane.
2. Horizontal-unilateral: Spur; half-long; cane.
3. Horizontal-bilateral: Spur; half-long; cane.
All possible combinations indicated by this table represent 24 variations. Some of these combinations, however, are not used and some are rare. The most common are shown in Figs. 23, 24, 25, 26 and 27.
Figure 23 B represents a headed, vase-formed vine, with a medium trunk and short fruit spurs. This is the most common system used in all parts of California and is suited for all small growing vines which bear on the lower buds, for most wine grapes and for Muscats. The unit of pruning in this case is a fruit spur of 1, 2, or 3 internodes, according to the vigor of the variety and of the individual cane.
Figure 23 A differs from 23 B only in the higher trunk and longer arms. It is commonly used for Tokay and other large growing varieties, especially when growing in rich soil and when planted far apart.
Figure 23 C has the same form of body as A and B, except that the arms are somewhat less numerous. The unit of pruning is a short fruit cane of four to five internodes, accompanied by a renewal spur of one internode. It is suited for vigorous table grapes, which do not bear well on short spurs. It is used especially for the Cornichon and Malaga in rich soil. This is a difficult system to keep in good shape owing to the tendency for all the vigor to go to the growth on the ends of the fruit canes. It is difficult to obtain vigorous canes on the renewal spurs. Occasional short pruning is usually necessary to keep the vines in proper shape.
Figure 24 A is similar to 23 C in form, but the number of arms is still further reduced to 2, 3, or at most 4. The unit of pruning is a fruit cane of 2-1/2 to 3-1/2 feet with its renewal spur. Owing to the length of the fruit canes they require support and are tied to a high stake.
This method is used in a large number of vineyards with Sultanina, Sultana and certain wine grapes, especially Semillon and Cabernet. It is not to be recommended in any case, as it has several very serious defects.
The difficulty of obtaining new wood from the renewal spurs is even greater than in the system shown in Fig. 23 C. The length and vertical position of the fruit canes cause the main growth and vigor of the vine to be expended on the highest shoots. The renewal spurs are thus so shaded that, even though their buds start, the shoots make but a weak growth. The result is that at the following pruning all the good new wood is at the top of the fruit canes of the previous year, where it cannot be utilized. The pruner has to choose then between reverting to spur pruning and getting no crop or using the weak growth from the renewal spurs for fruit canes, in which case he may get blossoms but little or no fruit of any value.
Other defects of this method are that the fruiting shoots are excessively vigorous and therefore often tend to drop their blossoms without setting and the fruit when produced is massed together so that it ripens unevenly and is difficult to gather. It also requires a tall and expensive stake.
Figure 24 B represents an improvement on the last system. It differs only in the method of treating the fruit canes. These are bent over in the form of a circle and tied by their middle part to a stake which may be smaller and lower than that needed for the vertical canes.
This bowing of the canes has several useful effects. The change of direction moderates the tendency of the vigor of the vine to expend itself only on the terminal shoots. More shoots therefore are formed on the fruit canes and as their vigor is somewhat decreased they tend to be more fruitful. The slight mechanical injury caused by the bending operates in the same direction.
The excess of vigor thus being diverted from the fruit canes causes the renewal spurs to form vigorous shoots, which soon grow above the fruit shoots and obtain the light and air they need for their proper development. This method is used successfully for certain wine grapes such as Riesling, Cabernet, and Semillon. It is unsuited to large vigorous varieties or for vines on rich soil planted wide apart. In these cases two fruit canes are usually insufficient and, if more are used, the grapes and leaves are so massed together that they are subject to mildew and do not ripen evenly or well. The bowing and tying of the canes requires considerable skill and care on the part of the workmen.
The body, arms, and annual pruning of the system shown in Fig. 25 are similar to those of Fig. 24, with the exception that the arms are given a fan-shaped arrangement in one plane. It differs in the disposal of the fruit canes, which are supported by a trellis stretching along the row from vine to vine.
This method is largely used for the Sultanina (Thompson's Seedless), and is the best system for vigorous vines which require long pruning, wherever it is possible to dispense with cross cultivation. It is also suitable for any long-pruned varieties when growing in very fertile soil.
Figure 26 is a photograph of a four-year-old Emperor vine, illustrating the vertical cordon system. It consists of an upright trunk 4-1/2 feet high with short arms and fruit spurs scattered evenly and symmetrically from the top to within fifteen inches of the bottom. This system is used in many Emperor vineyards in the San Joaquin Valley.
Its advantages are that it allows the large development of the vine and the large number of spurs which the vigor of the Emperor demands, without, on the one hand, crowding the fruit by the proximity of the spurs or, on the other hand, spreading the vine so much that cultivation is interfered with. It also permits cross cultivation.
One of its defects is that the fruit is subjected to various degrees of temperature and shading in different parts of the vine and the ripening and coloring are often uneven. A more vital defect is that it cannot be maintained permanently. The arms and spurs at the top of the trunk tend to absorb the energies of the vine and the lower arms and spurs become weaker each year until finally no growth at all is obtained below. After several years, most of the vines therefore lose their character of cordons and become simply headed-vines with abnormally long trunks.
The cordon can be reestablished in this case by allowing a vigorous sucker to develop one year from which to form a new trunk the next. The following year the old trunk is removed entirely. An objection to this method is that it makes very large wounds in the most vital part of the vine—the base of the trunk.
Figure 27 is a photograph of a four-year-old Colombar vine, illustrating the unilateral, horizontal cordon system. It consists of a trunk about seven feet long, supported horizontally by a wire two feet from the ground. Arms and spurs are arranged along the whole horizontal part of the trunk.
This system accomplishes the same objects as the vertical cordon. It allows a large development of the vine and numerous fruit spurs without crowding. It is superior to the vertical cordon in the distribution of the fruit, which is all exposed to approximately the same conditions owing to the uniform distance from the ground of the fruit spurs. All parts of the trunk producing an annual growth of wood and fruit are equally exposed to light and the tendency of the growth to occur principally at the part of the trunk farthest removed from the root is counteracted by the horizontal position. There is not the same difficulty therefore in maintaining this form of vine permanently that there is with the vertical cordon. |
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