GREAT OPPORTUNITIES IN THE GRAPE
GENERATIONS OF GRAPE EXPERIMENTS HELP US
The grape is the patrician among climbing plants as the strawberry is among trailers. The family to which it belongs is one of the smallest, as regards number of species, among plant tribes. But it is an oligarchy having very great distinction. What the membership lacks in numbers it makes up in quality. The grape is known everywhere and has been cultivated by man from the earliest times. Doubtless as much attention has been given to it as to any other tribe of plants. Indeed it may be questioned whether there is another that can compete with it in this regard. Of course the main reason for the extreme favor shown the grape by man has been all along the capacity of the plant to produce a fruit having a juice of unique quality that ferments readily to form a potable beverage. It is as a producer of wine rather than as a producer of fruit for the table that the vine has everywhere gained greatest popularity. Nevertheless the quality of its fruit is altogether noteworthy, and such as to give the plant distinction in the eyes of the horticulturist, even were it considered solely as a producer of table fruit. Moreover, there are certain kinds of grape that contain so high a sugar content that they dry without fermenting, constituting a third important commercial product-the raisin. All in all, then, it is easy to understand why the grape must be considered as a fruit standing in a class by itself, and having importance second to none. The manner of growth of the grape and the character of the clusters in which its fruit is borne are no less distinctive. No other fruit under cultivation in the least resembles the grape in either regard. And as to shape and appearance of the individual berries no less than in the matter of fragrance and flavor the grape manifests the same individuality. Different varieties show diversity of form and color and flavor, to be sure, but no grape of any variety is likely to be mistaken for a fruit of any other kind whatsoever. It is clear that we cannot attempt in the space at command to present anything like a comprehensive story of the growth and development and world-conquest of this extraordinary fruit. Nor would it comport with the present purpose to do so. The main facts as to grape culture are matter of common knowledge. Our concern must be with such features of habit, and constitution, and adaptability of the grape as particularly concern the plant developer, and have to do with the possibilities of improvement. In particular, of course, here as elsewhere, we shall be concerned with a presentation of the work done at Santa Rosa and Sebastopol in connection with the development of this plant. This, as will appear presently, has looked chiefly to the improvement of the grape as a table fruit. I have not been concerned with varieties of the grape that are especially utilized by the maker of wine. These have been specialized to the point of approximate perfection in the great wine-growing districts, and it would be useless to experiment with them in any region except the one in which they are to be cultivated, because it is well-known that the grape takes directly from the particular soil in which it grows something of the unique qualities of flavor that determine the rank of any so-called good wine in the estimate of the connoisseur. It is only in two or three small districts of France, for example, that grapes are grown from which the clarets can be made that are adjudged superlative in quality. It does not at all suffice to transplant cuttings of these vines to other regions. It would be necessary to transplant soil and climate also if the grapes are to retain their unique qualities of wine production. But the case of the grape considered as a table fruit is obviously different. Even though this also is doubtless influenced by the soil, the tests applied to it are not of quite so refined a character, and the grape developed in one region may be expected to retain at least approximately its unique flavor when grown in another climate. So I have striven to develop varieties that would have commendable qualities of fruit and such qualities of hardiness of vine and prolific bearing as would make them suited to cultivation throughout wide territories. Here as elsewhere I have had in mind the needs of horticulturists not in one region merely, but in many regions, and have endeavored to produce plants having the widest possible adaptability to varying soils and climates. The measure of success that has attended this effort in the case of the grape will be partially revealed in the ensuing pages. During a period covering 40 years I have probably raised no less than 75,000 to 100,000 seedling grapes from the best table varieties. I have hybridized many varieties, both European, American, cultivated and wild; also other wild species from Mexico, Australia, China, and Japan. I have likewise attained interesting results by working with bud sports, and with the tuberous grape of Mexico.
MATERIALS AND METHOD
To raise grape seedlings, it is only necessary to gather the seed from the variety desired, and keep them barely moist until planting time. Plant as soon as the frost is out of the ground in well-drained land, in rows about 3 or 4 feet apart. Scatter the seed thinly in narrow drills. Cover with sandy or leaf-mould soil, about one inch deep in a humid climate, a little deeper in dry soil like that of California. In the latter case it is well to have the upper half of the covering of sawdust, so that the seedlings do not have too great a weight to lift in pushing through the soil. During the summer the very poor seedlings, those which are attacked by mildew and which have made weak, uncertain growth may be uprooted at once, giving the others a better chance. Later, while the plants are dormant, transplant the most promising of these to rows about 12 feet apart, the individual plants being from one to two feet apart in the rows, according to the variety. Like most other cultivated fruits, grapes do not come true from the seed. Among American grapes, if seeds from a vine bearing black fruit are planted, about 99 out of 100 black-fruited seedlings may be expected. With red grapes about the same proportion will follow the parent color. But from a white grape probably less than one-fourth will come white. With the European grape, Vitis vinifera, the most variable and commercially the most important species in the world, the proportion would be wholly different in most cases. Planting a red grape one may expect half red or half black, the tendency being slightly more toward red or black grapes than white, but the proportions varying indefinitely. Certain qualities of the inherent constitution of the plant are markedly heritable. Thus the seeds from a strong-growing grape vine are likely to produce strong-growing seedlings. Productive grapes will usually produce a high proportion of productive seedlings. A grape subject to mildew is almost certain to produce a large proportion of seedlings subject to mildew. A variety having abnormally large leaves will not often reproduce that tendency in its seedlings for an abnormality is more apt not to reproduce itself, there being a tendency to return to the normal condition, which has existed for perhaps a thousand years. By planting seeds of an early grape, a great proportion of early grapes would be expected, and vice versa, but in almost every case both early and late, large and small, black and white, sweet and sour, strong-growing and weak-growing grapes will be produced among a lot of grape seedlings from any variety which has been long cultivated and is the result of hybridization. In a wild species, the variation would be mostly in the size of the plants and very little in any other respect. The first crop of fruit on the young vine is not a very accurate test of its future fruiting capacity. Almost without exception the fruit improves each season for several years both in the size of the bunches and in the quality of the fruit.
GRAPES FROM MANY LANDS
With the grape as with other plants I have sought material for development in far places; but have also utilized the native species. A brief notice of the different species that have contributed to the experiments will suggest the scope of the work. An interesting local species is Vitis Californica. This is an extremely strong vine, climbing a tree to a height of 75 or 100 feet. It is often found along the banks of creeks and rivers where it may attach itself to a young alder. As alder and grape grow, the tree supports the vine until it reaches a height of sometimes 100 feet and has a trunk 12 to 18 inches in diameter-which may seem almost incredible to eastern people unfamiliar with our flora. The fruit of the California grape is produced in small quantity and is quite variable in this locality. It ripens late, is sour, without flavor, and is generally insignificant in all respects. It is sometimes used for jellies and even for wine. Of the world-wide and supremely important commercial species commonly called the European grape (Vinus vinifera) I have worked largely with the Tokay variety with the idea of inducing this vigorous vine, which bears such an abundance of large, handsome fruit, to combine hardy qualities and freedom from mildew with its characteristic excellence of fruit. The fruit of many of the seedlings is quite acid, but some are far sweeter than the Flame Tokay, and much earlier, which is most important as the Flame Tokay ripens too late for our coast climate. These seedlings have of course been rigidly selected to avoid mildew, susceptibility to which is one of the faults of the Tokay, especially in the coast region. Some of the seedlings of the Flame Tokay are white, some black, some reddish, some of a blue-gray color. Very few of them resemble the Flame Tokay in form, color or quality of fruit, most of them incline to the round form of the ordinary V. vinifera. It is not uncommon to find natural hybrids of the California grape and the European grape growing wild alongside the vineyards. The strains of the California species are in some of the strongest-growing forms of cultivated grapes that are recommended as stocks for the varieties of European grape that are subject to injury from phylloxera.
WORK WITH STRANGE SPECIES
Mr. M. K. Seralian, who removed from Palestine to America some years ago, secured cuttings of the best Syrian grapes. The vines from these cuttings have habits of growth not unlike those of the Flame Tokay seedlings planted at the same time, and are now about the same size. Among them is one identical with our so-called Sweetwater grape. Another was certainly Thompson's Seedless-a stray variety renamed since it was imported to California about 1880, and recently identified as Sultanina. It is an extremely productive, light colored, strong growing, yellowish-white grape which has to be pruned longer than most others of the vinifera class in order to get big crops which it produces under ordinary vineyard cultivation in California. Sultanina and another called Sultana are grapes of medium size but absolutely seedless. They are put up in great quantities in California as seedless raisins, and are displacing the dried grapes of Corinth or so-called Zanta currants so extensively imported from Greece and Turkey-to which they are greatly superior. Among these seedling Syrian grapes there is one early and productive class, absolutely new to California growers. Most of the Syrian grapes are noticeably different in several particulars from the other grapes of Europe and northern Africa. The stems are more slender, the peduncles quite small, yet strong and wiry, the bunches are very pleasing in form, the grapes usually being set full and all of one size, and the bunches are not usually so eroded as those of many varieties of the common grape. The seeds also are very small-almost absent. Yet all of the varieties among this lot of twelve or more produce some seeds, with the exception of the Thompson's Seedless. The seeds, however, are quite tender, being hardly noticeable. The skins of most of them are thin and transparent. Having raised a great number of seedlings from these Syrian grapes, I find them to be remarkably precocious, coming into fruitage early, remarkably heavy croppers, and while more uniform in character than most of the vinifera seedlings, yet they nearly all contain an astringent principle which is seldom found in the ordinary grapes. With this exception, they are the most promising lot of seedlings which I have hitherto raised. About 1890 the U.S. Government imported a lot of grapes from the Mediterranean region, but none of them compared with these Syrian grapes, which seem to be distinct, and some of which will probably prove of great value to California. Most of these grapes are oval in form, not round as is usual with other grapes. The Vitis antarctica, which has several other botanical names, is a curious climber from Australia which I have grown many times from imported seed. It is a little tender and especially sensitive to wet weather, and though it is interesting I have not experimented much with it. The Vitis Coignetiae from China is an exceedingly strong-growing vine with immense leaves. The foliage is beautifully colored in the fall-scarlet, crimson, yellow, or brown. But there is a great diversity in the seedling vines in the color of the foliage. Those with brilliant scarlet autumn colors are generally considered the best. There are also crimson ones. There was a Vine growing on my Sebastopol bungalow for years which bore small clusters of insignificant fruit, but handsome foliage. The Vitis hypoglossa is another uncommon grape which I have grown for my own amusement and interest. The Vitis rotandifolia, which has also half a dozen more botanical names, is a tremendous grower. It must be thinned out quite extensively in order to get any fruit; the seedlings of these make a mass of foliage and small branches, so there is no opportunity for the vines to produce much fruit. The various Scuppernongs are derived from this southern species. I have grown them from seed on numerous occasions. In a few cases these have produced scanty fruits, but they were finally destroyed as they make too much growth and too little fruit. I have also grown the mustang or overbearing grape, V. Candicans; the sugar grape, V. rupestris; the V. monticola, Texana or Foexeana, the V. vulpina or cordifolia-in fact I have worked more or less with nearly or quite all the North American species and many of the hybrids produced by Mr. Munson and others. Seeds of the tuberous grape of Mexico have been sent me several times. It seems to require a thoroughly well-drained soil and a very warm climate. The first two lots of seeds received were failures on account of being placed in irrigated soil which was not suitable to them. Some of the third lot of seeds were placed in sandy, well-drained soil, and made large vigorous vines the first season. They somewhat resemble the Muscat of Alexandria in foliage and growth and have rather large, sweet, potato-like roots. However, our winter climate did not suit them and these also died, so I have made no further attempt at raising them. These Mexican tuberous grapes are said to produce a fine fruit in large clusters, much resembling the Muscat of Alexandria.
VARIATIONS IN SEEDLINGS OF A BUD-SPORT
My constant effort to take advantage of any disturbance in the heredity of a species or variety is justified strikingly in working with the grape. The best seedlings which I have ever produced were from the grape called Pierce or Isabella Regia, a variety which originated as a sporting branch from the common Isabella on Mr. J. Pierce's place near San Jose, Cal. This Pierce grape is the same color as its parent, the Isabella, but the berries are more than twice as large though not increased in number on the cluster. The vine is very much stronger and the foliage much larger, so much so that the difference is noticeable at a considerable distance. Large quantities of seedlings from the Isabella Regia were raised, partly for the purpose of noticing whether bud-sports would reproduce themselves from seed and partly because it promised to be a fine variety to work upon for improvement. Among the numerous seedlings which were fruited the variations were most astonishing, much more so than with most grapes. Whether this is on account of the Isabella having been moved to a new climate, thus changing its hereditary tendencies, or whether bud sports in general are apt to produce more variable seedlings, I am not yet able fully to demonstrate. Some of these selected vines which were fruited are unusually strong growers, some were as weak in growth as the ordinary cultivated varieties of grapes; some bore enormous bunches of grapes, some had only a few small clusters. One of these Isabella Regia seedlings is the earliest grape ever recorded, ripening nearly a month before the Early Amber, Sweetwater, and other American and European grapes. It is, however, small in size and not productive.
THE EARLIEST AND LATEST GRAPES ON RECORD
Another very large black grape, produced on a large, vigorous vine, ripens nearly five weeks before its parent. This is the earliest large grape known. It has very delicious flavor and quality. It was temporarily called the "Early Black," but was subsequently rechristened the Montecito by Mr. John M. Rutland, who purchased it for introduction in Australia. In contrast with these early-ripening seedlings are others that do not fully ripen their fruit until December and January. These are valuable in California if protected from the rains, as they extend the season almost indefinitely. Though the parent plant bore black grapes, some of the seedlings bore white, yellow, red, or purplish-black fruit. Some varieties were enormous producers. Owing to pressure of other matters, I have made no attempt to introduce any of these grapes, but am satisfied that none can compete with some of them for table use. Among the seedlings of the second generation raised from my own vines were three anomalous vines, of great interest. One of these was the exact counterpart of the California wild grape. The second was closely similar though not quite identical; and the third might be called a hybrid in general appearance. As there were no wild California vines growing within fourteen miles of the place where these grapes were growing, I can only account for the appearance of these degenerates, as they might be called, on the theory that our wild California grape and the eastern wild grape from which the Isabella originated were descended from a common stock, and these three plants were reversions. Two of these vines grew the first season to the height of nearly eight feet when the other seedlings had grown to only one or two feet in height. The third one grew twelve feet or more, while most of the others had grown only about as many inches. The foliage was exactly like the California wild grape, as was the wood, fruit, and general appearance throughout. These seedlings have created much speculation as to their origin among experts who have seen them. They are best explained, I think, on the theory proposed above. Nearly three-fourths of the Isabella Regia seedlings bore partially seedless fruit. About half the grapes on each bunch usually were altogether seedless. Some entire clusters were seedless. Yet other vines of the same fraternity bore fruit in which the seeds were unusually large. By selection among these vines I have developed several races of nearly seedless grapes that are of exceptional quality. The best of these will be introduced, and they will also be of value in hybridizing experiments for the production of seedless grapes of other varieties. Once produced, such varieties must obviously be propagated by cuttings, but this of course presents no difficulties. The matter of hybridization, crossing, and selection of fruit having been gone into quite extensively in early chapters, only a glimpse of the special features of the work with the grape has been here recorded. The methods of crossing and selection having been discussed in previous chapters, it would be mere repetition to give them here; and for this reason the details have not been elaborated as fully as in some chapters on other fruits. A great number of experiments with the grape are now being carried on that are approaching completion, and I have a large number of unique and valuable grape varieties which are awaiting introduction.
This text is from: Luther Burbank: his methods and discoveries and their practical application. Volume 6 Chapter 6