Popular Science Monthly/Volume 82/April 1913/The Domestication of American Grapes
|THE DOMESTICATION OF AMERICAN GRAPES|
AGRICULTURAL EXPERIMENT STATION, GENEVA, N. Y.
THERE are about forty species of grapes in the world, more than half of which are found in North America. Few other plants on this continent grow wild under such varied conditions and over such extended areas. Thus, wild grapes are found in the warmer parts of New Brunswick; on the shores of the Great Lakes; everywhere in the rich woodlands and thickets of the North and Middle Atlantic States; on the limestone soils in the mountainous parts of Kentucky, Tennessee and the Virginias; and they thrive in the sandy woods, sea plains and reef-keys of the South Atlantic and Gulf States, where a single vine of the Scuppernong often clambers over trees and shrubs for a hundred feet or more. While not so common west of the Mississippi, yet some kind of wild grape is found from North Dakota to Texas; grapes grow on the mountains and in the canyons of all the Rocky Mountain States; and several species thrive on the Mexican borders and in the far southwest, where they furnished the early Spanish padres with grapes for wine and suggested the planting of the first vineyards in America.
While it is possible that all of the native grapes have descended from an original species, the types are now as diverse as the regions they inhabit. The wild grapes of the forests have long slender trunks and branches whereby their leaves are better exposed to the sunlight. Two shrubby species do not attain a greater height than four or five feet; these grow in sandy soils, or among the rocks well exposed to sun and air. Another runs on the ground and bears foliage almost evergreen. The stem of one species attains a diameter of nearly a foot, bearing its foliage in a great canopy; from this giant form the species vary to sorts with slender, graceful, almost delicate, climbing vines. Wild grapes are quite as varied in climatic adaptations as in structure of vine, and grow luxuriantly and bear fruit in almost every condition of heat or cold, wet or dry, capable of supporting fruit-culture in America. So many of the kinds have horticultural possibilities that it seems certain that some of them can be domesticated in all of the agricultural regions of the country, their natural plasticity indicating, even if it were not known from experience, that all can be domesticated.
Leif the Lucky, the first European to visit America, if the Icelandic records be true, christened the new land Wineland after its grapes. Captain John Hawkins, who visited the Spanish settlements in Florida in 1565, mentions the wild grapes among the resources of the New World, with the statement that the Spaniards "had made twenty hogsheads of wine in a single season." Amadas and Barlowe, sent out by Baleigh in 1584, described the coasts of the Carolinas as, "so full of grapes that in all the world like abundance can not be found." Captain John Smith, writing in 1606, describes the grapes of Virginia and rec- ommends the culture of the vine as an industry for the newly founded colony. Few, indeed, are the explorers of the Atlantic seaboard who do not mention grapes among the plants of the country. Yet none saw intrinsic value in these wild vines. To the Europeans the grapes of the Old World alone were worth cultivating and the vines growing everywhere in America only suggested that the grape they had known across the sea might be grown in the new home.
During colonial times and the first half century of the union, efforts to grow European varieties of grapes in America were continuous. Some of the experiments were on a large scale and in the hands of ex- pert vine growers, yet all resulted in failure. Several large companies undertook grape-growing and wine-making in the years following the Eevolution ; the efforts of a few of these are worth noting.
Peter Legaux, a Frenchman, founded a company to grow grapes at Spring Mill, near Philadelphia, in 1793. John James Dufour, a Swiss, came to America in 1793 to engage in grape-growing and became the head of the Kentucky Vineyard Society in the valley of the Ohio in Kentucky and Indiana. The Harmonists, a religious-socialistic com- munity, planted ten acres of grapes about 1805 near Pittsburgh, and later made another plantation at New Harmony, Indiana. When the Napoleonic wars were over, a number of Bonaparte's exiled officers came to America and founded the Vine and Olive Colony on land granted them by Congress on the Tombigbee River in Alabama. Here one hundred and fifty French settlers spent several years in vain attempts to grow European grapes in America. In a rough and hardly explored country, part of which was overflowed half the year, with all the sickness inherent to such a location, unaccustomed to field work and the hardships of a new country, the attempt to grow grapes, where failure was predestined because of natural obstacles, became for these French officers and their families a tragedy which ended in great suffer- ing and the impoverishment of all and the death of many.
It is only on the Pacific coast and in favored valleys of the Eocky Mountains that Vitis vinifera, the grape of the Old World, can be grown. The great viticultural industry of California is founded upon the successful culture of this species. The native grapes can be grown, but they can not compete on the Pacific coast with the Old World grape for any purpose. The success attained in the cultivation of this species west of the continental divide makes all the more remarkable its com- plete failure east of the divide.
For three centuries from the first recorded attempt to grow the Old World grapes in America, the causes of the failures were a mystery.
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As one of the first experimenters stated, "a sickness takes hold of the vines and they die." The agent causing the sickness is the phylloxera, a tiny plant louse, undiscovered until the last half of the nineteenth century, which works on the leaves and roots of the European grapes, but which does comparatively little harm to American species. Un- doubtedly, the resistance of native grapes to the phylloxera is due to natural selection in the contest that has been going on for untold ages between host and parasite. Three other pests, black-rot, downy mildew and powdery mildew, are destructive to European grapes in America. The climate, too, in eastern North America alternates between hot and cold, wet and dry, and the Old World grapes grow well only in equable temperatures and conditions of humidity. The leaves of the Old World grape are thin and soft and the roots fleshy ; the leaves of the American species are thick and leathery and the roots hard and fibrous. These differences in the structure of the species of Vitis explain their adapta- tions to the two climates.
That American viticulture must depend upon the native species for its varieties began to be recognized at the beginning of the nineteenth century, when several large companies engaged in growing foreign grapes failed, and a meritorious native grape made its appearance. The vine of promise was a variety known as the Alexander. Thomas Jeffer- son, ever alert for the agricultural welfare of the nation, writing in 1809 to John Adlum, one of the first experimenters with an American species, voiced the sentiment of grape experimenters, in speaking of the Alexander:
I think it will be well to push the culture of this grape without losing time and efforts in the search of foreign vines, which it will take centuries to adapt to our soil and climate.
The Alexander is an offshoot of the common fox grape, Vitis Idbrusca, found in the woods on the Atlantic coast from Maine to Georgia and occasionally in the Mississippi Valley. The history of the variety dates back to just before the Revolutionary War, when, according to William Bartram, the Quaker botanist, it was found growing in the vicinity of Philadelphia, by John Alexander, gardener to Governor Penn of Penn- sylvania. Curiously enough, it came into general cultivation through the deception of a nurseryman. Peter Legaux, mentioned before, in 1801 sold the Kentucky Vineyard Society fifteen hundred grape cut- tings, which he said had been taken from an European grape, introduced from the Cape of Good Hope, therefore, called the " Cape " grape. Legaux's grape turned out to be the old Alexander. In the new home the spurious " Cape " grew wonderfully well and as the knowledge of its fruit fulness in Kentucky, Ohio and Indiana spread, demand for it increased and with remarkable rapidity, considering the time, it came into general cultivation in the parts of the United States then settled.
Of the several species of American grapes now under cultivation,
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Vitis labrusca, first represented by the Alexander, has furnished more cultivated varieties than all the other American species together, no less than 500 of its varieties having been grown in the vineyards of the country. There are several reasons why it is the most generally cultivated species. It is native to the parts of the United States in which agriculture soonest advanced to a state where fruits were desired. In the wild, the Labrusca grapes are the most attractive, being largest and handsomest in color — among all grapes it alone shows black, white and red-fruited forms on wild vines. There is a northern and a south- ern form of the species and its varieties are therefore widely adapted to climates and to soils. The flavor of the fruits of this species, all things considered, is rather better than that of any other of our wild grapes, though the skins in most of its varieties have a peculiar aroma, some- what pronounced in the well-known Concord, Niagara and Worden, which is disagreeble to any who are accustomed to the pure flavors of the European grapes. Unfortunately few varieties of this species are adapted to wine-making, as the fruits lack both sugar and acid and impart to wines an unpleasant aroma and taste. All varieties of Vitis labrusca submit well to vineyard operations and are vigorous, hardy and productive, though they are more subject to the dreaded phylloxera than are most of the other cultivated native species.
Of the many grapes of the labrusca type, at least two deserve brief mention.
The Catawba, the first American grape of commercial importance, is the most interesting variety of its species. The origin of the variety is not certainly known, but all evidence points to its having been found about 1800 on the banks of the Catawba River, North Carolina. It was introduced into general cultivation by Major John Adlum, soldier of the revolution, judge, surveyor, and author of the first American book on grapes. Adlum maintained an experimental vineyard in the District of Columbia, whence in 1823 he began the distribution of the Catawba. At that time the center of American grape culture was about Cincinnati, and an early shipment of Adlum's Catawbas went to Nicholas Longworth, grandfather of the present bearer of that name, and was by him distributed throughout the grape-growing centers of the country. As one of the first to test new varieties of American grapes, to grow them largely and to make wine commercially from them, Nicholas Longworth is known as the "father of American grape culture."
The Catawba is still one of the four leading varieties in the vine- yards of eastern America. The characters whereby its high place is maintained among grapes are : great elasticity of constitution, by reason of which it is adapted to many environments; rich flavor, long-keeping quality, and handsome appearance, qualities which make it a very good dessert grape; high sugar content and a rich flavor of juice, so that
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from this grape is made a very good sweet or dry wine, the latter entering into a blend for nearly all of the champagne produced in east- ern America. The vines, too, are vigorous, hardy and productive. The characters of Catawba are readily transmissible and it has many pure- bred or hybrid offspring which more or less resemble it.
The second commercial grape of importance in American viticulture is the Concord, which came from the seed of a wild grape planted in the fall of 1843 by Ephraim W. Bull, of Concord, Massachusetts. The new variety was disseminated in the spring of 1854, and from the time of its introduction the spread of the culture of this grape was phe- nomenal. By 1860 it was the leading grape in America and so re- mains. It furnishes, with the varieties that have sprung from it, seventy-five per cent, of the grapes grown in eastern America. The characters which distinguish it are : adaptability to various soils, fruit- fulness, hardiness, resistance to diseases and insects, certainty of matur- ity and attractive appearance. It is produced so cheaply that no other grape can compete with it in the markets. It is, as Horace Greeley well denominated it in awarding it the Greeley prize for the best Amer- ican grape, " the grape for the millions."
Long before the northern fox grapes had attained prominence in the vineyards of the north, the Scuppernong had been partially domesticated in the south. It is a variety of Vitis rotundifolia, a species which runs riot from the Potomac to the Gulf, thriving in many diverse soils, but growing only in the southern climate and preferring the seacoast. The Scuppernong has been cultivated somewhat for its fruit or as an orna- mental from the earliest colonial times. It is certain that wine was made from this species by the English settlers at Jamestown. Vines of it are now to be found on arbors, in gardens, or half wild on fences in nearly every farm in the South Atlantic States. That the rotundi- folia grapes have not more generally been brought under cultivation is due to the bountifulness of the wild vines, which has obviated the neces- sity of domesticating them. The fruit of its varieties, to a palate unac- customed to them, is not very acceptable, having a musky flavor and odor and a sweet, juicy pulp, which is lacking in sprightliness. Many, however, acquire a taste for these grapes and find them pleasant eating. The wines from Vitis rotundifolia partake too much of the muskiness of the fruit unless blended with those of other species. The great defect of this grape is that the berries part from the pedicels as they ripen and perfect bunches of grapes can not be had — in fact, the crop is often harvested by shaking the vines so that the berries drop on sheets beneath. Despite these defects a dozen or more varieties of rotundi- folias are now under general cultivation in the cotton belt and interest in their domestication is increasing.
The south has another grape which, while not so early brought under domestication or now so generally grown, has greater horticultural pos-
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sibilities than Vitis rotundifolia. This is Vitis aestivalis, the summer grape, or, to distinguish it from the rotundifolias, the bunch grape of southern forests. The cestivalis grapes are preeminent in wine-making in eastern America. The wines from this species make the best red wines, usually of the claret and Burgundy types, to be had from Amer- ican vines. A defect of these grapes is that they contain an excess of some of the necessary elements which make good wines ; as color, tannin, acidity and bouquet, but these faults are easily remedied by blending. There are now a score or more well-known varieties of Vitis cestivalis, of which the best known is Norton, which probably originated with Dr. D. 1ST. Norton, of Eichmond, Virginia, in the early part of the nine- teenth century. The berries of the true aestivalis grapes are too small, too destitute of pulp and too tart to make good dessert fruits. Domesti- cation of this species has been greatly retarded by a peculiarity of the species which hinders in its propagation. Grapes are best propagated from cuttings, but this species is not easily reproduced from cuttings and the difficulty of securing good young vines has been a serious handicap in its culture.
There are two sub-species of Vitis aestivalis which promise much for American viticulture. Vitis aestivalis bourquiniana, known only under cultivation and of very doubtful botanical standing, furnishes American viticulture several valuable varieties. Chief of these is the Delaware, the introduction of which sixty years ago from the town of Delaware, Ohio, raised the standard in quality of our grapes to that of the Old World. No European grape has a richer or more delicate flavor or a more pleasing aroma than the Delaware. While a northern grape it can be grown in the south and thrives under so many different climatic and soil conditions and under all is so fruitful that, next to the Concord, it is the most popular American grape for garden, vine- yard and wine-press. Without question, however, the Delaware contains a trace of European blood.
Another offshoot of this sub-species is the Herbemont, which in the south holds the same rank that the Concord has in the north. The variety is grown only south of the Ohio, where it is esteemed by all for a dessert grape and for its light red wine. It is one of the few American varieties which finds favor in France, being cultivated in southwest France as a wine grape. Its history goes back to a colony of French Huguenots in Georgia before the Eevolutionary War. Very similar to the Herbemont is the Lenoir, also with a history tracing back to the French in the Carolinas or Georgia in the eighteenth century.
The other sub-species of Vitis aestivalis is Vitis aestivalis lincecumii, the post-oak grape of Texas and of the southern part of the Mississippi Valley. Eecently this wild grape has been brought under domestica- tion and from it have been bred a number of most promising varieties for hot and dry regions.
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As agriculture becomes more diversified in the south, when cotton and tobacco no longer hold complete sway, the varieties of Vitis aestivalis and its two sub-species will become important agricultural assets.
The north, too, has a wine grape from which wines of their types nearly equalling those of the southern aestivalis are made. This is Vitis riparia, the river grape, the most widely distributed of any of the native species. It grows as far north as Quebec, south to the Gulf of Mexico, and from the Atlantic to the Kocky Mountains. Fully a century ago a wine-grape of this species was cultivated under the name Worthington, but the attention of vineyardists was not turned to the riparias until after the middle of the last century, when the qualities of its vines attracted the attention of French viticulturists. Phylloxera had been introduced from America into France and threatened the existence of French vineyards. After trying all possible remedies for the scourge it was discovered that it could be overcome by grafting the European grapes on American vines resistant to the phylloxers. A trial of the promising species of New World grapes showed that the vines of Vitis riparia were best suited for the reconstruction of French vineyards, being not only resistant to the phylloxera, but also vigorous and hardy. It is interesting to note that a large proportion of the vines of Europe, California and other grape-growing regions are grafted on the roots of this or of other American species and the viticulture of the world is thus largely dependent upon these grapes.
The French found that a number of the riparia grapes introduced for their roots were valuable as direct producers for wines. The fruits of Vitis riparia are too small and too sour for dessert, but they are free from the disagreeable tastes and aromas of some of our native grapes and therefore make very good wines. The best known of the varieties of this species is the Clinton, which is generally thought to have origi- nated in the yard of Dr. Noyes, of Hamilton College, Clinton, New York, about 1820. It is, however, probably the Worthington, of which the origin is unknown, renamed. There are possibly a hundred or more grapes now under cultivation wholly or in part from Vitis riparia, most of them hybrids with the American labrusca and the European vinifera, with both of which it hybridizes freely.
A curious fact in the domestication of all these species is that they did not come under cultivation until forms of them striking in value had been found. Catawba, representing the labrusca grapes ; the Scup- pernong, the rotundifolias ; Norton from Vitis aestivalis; the Delaware and Herbemont from the Bourquiniana grapes ; and Clinton from Vitis riparia, are, after a century scarcely excelled, though in each species there are many new varieties. It is with grapes as with all fruits ; the majority of the best varieties originate by chance and for the reason that a prodigious number of natural seedlings, pure or cross-bred, arise, and natural selection, while wasteful, is wonderfully effective.
That our best grapes have come from chance is not because of a lack of human effort to produce superior varieties. Of all fruits the grape has received most attention in America from the generation of plant-breeders just passing. Their product is represented by fifteen hundred varieties, a medley of the more or less heterogeneous characters of a dozen species. That these have not excelled is due more to a lack of knowledge of plant-breeding than to a lack of effort. Now that order and system, undreamed of a generation ago, have been disclosed by the brilliant discoveries in plant-breeding of the last decade, future efforts to improve grapes ought to be more fruitful than those of the past.
As early as 1822, Nuttall, a noted botanist, then at Harvard, recommended "hybrids betwixt the European vine and those of the United States which would better answer the variable climates of North America." In 1830 William Robert Prince, fourth proprietor of the then famous Linnean botanic nursery at Flushing, Long Island, grew ten thousand seedling grapes "from an admixture under every variety of circumstance." This was probably the first attempt on a large scale to improve the native grapes by hybridizing, though little seems to have come of it. Later a Dr. Valk, also of Flushing, grew hybrids from which he obtained the Ada, the first named hybrid, the introduction of which started hybridizers to work in all parts of the country where grapes were grown.Soon after Valk's hybrid was sent out, E. S. Rogers, of Salem, Massachusetts, and J. H. Ricketts, of Newburgh, New York, began to give viticulturists hybrids of the European vinifera and the American species which were so promising that enthusiasm and speculation in grape growing ran riot. Never before nor since has grape-growing received the attention in America given it during the decade succeeding the
introduction of Rogers' hybrids. It was the golden era for nurserymen. One of the grape propagators of that time tells of carrying, during this boom, a thousand dollars' worth of plants on his back from the nursery to the express office. It was the expectation of all that we were to grow in America, in these hybrids, grapes but little inferior, if at all, to those of Europe.
A statement of the difference between European and American grapes shows why American viticulturists are so eager to grow either purebreds from the foreign grape or hybrids with it.
European grapes have a higher sugar and solid content than the American species; they, therefore, make rather bettor wines, excepting champagnes, and keep much longer after harvesting and can be made into raisins. So, too, they have a greater variety of flavors, which are more delicate, yet richer, with a pleasanter aroma, seldom so acid, and are always lacking the disagreeable, rancid odor and taste, the "foxiness," of many American varieties. There is, however, an unpleasant astringency in some of the vinifera grapes and many varieties are without character of flavor. American table grapes, on the other hand, are more refreshing, the unfermented juice makes a pleasanter drink, all of the grape juice of the markets being made from native grapes, and, lacking sweetness and richness, they do hot cloy the appetite so quickly. The bunches and berries of the vinifera grapes are larger, more attractive, and are borne in greater quantities. The pulp, seeds and skins are somewhat objectionable in all of the native species and scarcely so at all in Vitis vinifera. The berries of the native grapes shell from the stems so quickly that the bunches do not ship well. The vines of the Old World grapes are more compact in habit and require less pruning and training than do those of the native grapes, and, as a species, probably through long cultivation, they are adapted to more kinds of soil, to greater differences in environment, and are more easily propagated than the American species.
Because of these points of superiority in the Old World grape, since Valk, Allen and Rogers showed the way, American grape-breeders have sought to unite by hybridization the good characters of Vitis vinifera with those of the American grapes. Nearly half of the fifteen hundred grapes cultivated in eastern America have more or less vinifera blood in them. Yet despite the efforts of breeders few of these hybrids have commercial value. Whether because they are naturally better fixed, or long cultivation has more firmly established them, the vine
characters of Vitis vinifera more often appear in varieties arising as primary hybrids between the vinifera grapes and the native species, and the weaknesses of the Europeans, which prevent their cultivation in America, crop out. Hybrids in which the vinifera blood is more attenuated, as secondary or tertiary crosses, give better results.
Several secondary hybrids now rank among the best of the cultivated grapes. Examples are the Brighton and the Diamond. The first is a cross between Diana-Hamburg, a hybrid of a vinifera and a labrusca, crossed, in its turn, with the Concord, a labrusca; the second is a cross between Iona, also a hybrid of a vinifera, and a labrusca crossed with the Concord. Both were grown from seed planted by Jacob Moore, of Brighton, New York, in 1870. The Brighton was the first secondary hybrid to attract the attention of grape-breeders and its advent marked an important step in breeding grapes.
The signal successes achieved by the hybridizers of the European grape with the native species quickly led to similar amalgamations among the American species. Jacob Rommel, of Morrison, Missouri, beginning work about 1860, hybridized the labrusca and riparia grapes so successfully that a dozen or more of his varieties are still cultivated. All are characterized by great vigor and productiveness, and, though they lack the qualities which make good table grapes, they are among the best for wine-making. Rommel has had many followers in hybridizing the native species, chief of whom is Mr. T. V. Munson, Denison, Texas, who has literally made every combination of grapes possible, grown thousands of seedlings, and produced many valuable varieties.
The aim of hybridization in breeding plants is to combine the desirable and eliminate the undesirable characters of varieties or species in a new race. A plant, however, is such a complex sum-total of characters that no one can pi edict with any certainty the result of mingling the characters of two more or less distinct plants. Speculation thus quickens the charm of hybridization. The progeny of crossed grapes is always chaotic and must be passed through the sieve of selection, the meshes of which have grown larger and larger with use until now out of thousands of new forms a grape-breeder will retain few indeed.
Within the last decade, hybridizing has received a great impetus through the publication of Mendel's experiments. In the past hybridization has been a maze in which breeders lost themselves. Mendel's discovery in heredity assures a regularity of averages and gives a definiteness and constancy of action hereto wholly unknown in hybridization. It now appears that many of the characters of grapes follow
the law discovered by Mendel, and with this as a solid basis and the brilliant methods of Mendel for example, the further domestication of the species of this fruit ought to go forward in leaps and bounds.
Selection, continued through successive generations, so important in the improvement of field and garden plants, can play but small part in the domestication of the grape. The period between planting and fruiting is so long that progress would be slow indeed were this method
relied upon. Moreover, selection, as a method in breeding, is possible only when plants are bred pure, and it is the experience of grape breeders that in pure breeding this fruit loses in vigor and productiveness and that the variations are exceedingly slight and unstable. Many pure-bred grapes have been raised on the grounds of the New York Agricultural Experiment Station under the eyes of the writer, of which very, very few have surpassed the parent or have shown promise for the practise of selection.
From present knowledge it does not appear probable that new characters are produced in plants by hybridizing. New varieties so AMERICAN GRAPES . 35 >
nating are but recombinations of the characters in the parent — the com- bination is new but not the characters. Thus one parent of a hybrid grape may contribute color, size, flavor and practically all of the char- acters of the fruit and the other parent vigor, hardiness, resistance to disease and in general the characters of the vine. Or, of course, these and the other items in the make-up of the grape may be intermingled in any mathematically possible way. New characters probably appear as variations, and of these plant-breeders now recognize two kinds.
Nothing is more certan than that all offspring differ from their parents in many details — individual variation. Plant-breeders have long believed that by selecting desirable variations we have an efficient means of improving plants just as evolutionists have held and many continue to hold that evolution goes forward by means of natural selec- tion from these variations. But there is a new school, headed by the Dutch botanist, De Vries, who believe that these variations do not pro- duce anything new, but that they always oscillate around an average, and if removed from this for a time, they show a tendency to return to it. Whether the orthodox Darwinians or the De Vriesians are right does not matter here. The point is that the fluctuating variations of individuals, upon which Darwin chiefly founded his principle of natural selection, cut but a small figuie in the breeding of grapes. It is not certain that such, variations are heritable, nor whether they are capable of cumulative increase generation after generation, and, besides, as we have seen, selection must be consistent and persistent for too long a while to make it effective with grapes.
Evolution and plant-breeding have taken a fresh start through the recent amplification by De Yries of the theory that marked changes take place in plants through mutations, or characters which arise in a plant at once, with a single leap, and are stable from the time they arise. If this theory hold for grapes, it may be that there is a possi- bility of absolutely new characters arising in this fruit. It is well known that bud-sports, which in most cases must be called mutations, now and then arise in grapes. But these mutations have not as yet played an important part in producing new varieties. Not more than two or three of the fifteen hundred sorts now under cultivation are sus- pected of having arisen in this way. Until the causes of these muta- tions are known and they can be produced and controlled, but little can be hoped for in the amelioration of grapes through mutations.
Hybridization, then, has been and continues to be the chief means of domesticating grapes. " Fluctuations " and " mutations," produced other than by hybridizing, are too vague as yet for the grape-breeder to lay hands on. Even should the theory of De Vries be true, that noth- ing new — in the strict sense of the word — comes except through muta- tions, with more than a score of species of grapes, each with manifold distinct characters, all capable of fluctuating variations, there are many
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surprises in store for lovers of grapes in the new varieties that may be produced by hybridizing.
Whatever method of improvement is followed very much depends upon the immediate parentage. Some varieties, whether self-fertilized or crossed, produce much higher averages of worthy offspring than others. There is so much difference in varieties in this respect that to discover parents so endowed is one of the first tasks of the grape-breeder. Unfortunately, no way is known of discovering what the best progeni- tors are except by records of performance. The reasons for this pre- potency, seemingly well established in plants and animals alike, are not well explained by present knowledge. Often varieties of high cultural value are worthless in breeding because their characters seem not to be transmitted to their progeny, and to the contrary a variety good for but little in the vineyard may be most valuable from which to breed.
What are the results of a century's work in domesticating the wild grapes of America?
There are approximately in eastern America at the present time 240,000 acres of grapes, the product of which is largely sold for dessert purposes, but from it is manufactured yearly in the neighborhood of 10,000,000 gallons of wine, of which about 1,000,000 gallons are cham- pagne. The making of grape juice, an industry possible only with native grapes, has grown so rapidly that it is hard to estimate the out- put, but certainly not less than 2,000,000 gallons were sold in the mar- kets last year. It is doubtful if any other cultivated plants at any time in the history of the world has attained such importance, in so short a time from the wild state, as our native grapes.
Fifteen hundred varieties from twelve of the native species of grapes are now under cultivation. Almost every possible combination between these species has been made; they have been so mixed and jostled that species can no longer be recognized in the majority of varieties and the future breeder must work with characters rather than species. The methods of the past in domesticating the native grapes have been wholly empirical and extremely wasteful. Many have been called, but few chosen. But with the new knowledge of breeding and with the experience of the past, domestication ought to proceed with greater certainty. It is not too much to say that in this immense country, with its great differences in environment, we shall, some time, everywhere be growing grapes and of kinds so diverse that they will meet all of the purposes to which grapes are now put and the increasing demands for better fruits made by more critical consumers.