THE WILD BLUEBERRY TAMED The New Industry of the Pine Barrens of New Jersey BY FREDERICK V. COVILLE BOTANIST OF THE U. S. DEPARTMENT OF AGRICULTURE N AN article published last year describing the successful outcome of experiments in the growing of trailing arbutus from the seed, the incidental statement was made that "in the first trial blueberry plantation, in the pine barrens of New Jersey, blueberries are now produced of the size and color of Concord grapes. ."* This allusion aroused so much interest among the readers of the NATIONAL GEOGRAPHIC MAGAZINE that the writer has been asked to expand his statement into a description, with illustrations, of the progress that has been made in the new industry of blueberry culture. Five years ago, in this Magazine, a description was given by the writer of certain physiological peculiarities of the blueberry plant in which it differs fundamentally from the ordinary plants of agriculture. When given the kind of care, protection, and nourishment usually bestowed on cultivated crops, the blueberry sickens and dies (see picture, page 536). In a search for the cause of this peculiar behavior it was found that the healthy blueberry plant has on its roots a *The Cultivation of the Mayflower. NATIONAL GEOGRAPHIC MAGAZINE, May, 1915. Taming the Wild Blueberry. NATIONAL GEOGRAPHIC MAGAZINE, February, 191. minute fungus, invisible without the aid of a compound microscope, which, unlike most fungi, appears to be beneficial, not injurious, its particular beneficent action being to furnish nitrogenous food to the blueberry bush. So intimate, indeed, is the relation between the two that the blueberry appears unable to nourish itself properly without the assistance of the fungus. The problem of blueberry culture, therefore, became primarily the problem of growing the blueberry fungus, and the solution of this second problem lay in the character of the soil. The blueberry fungus requires an acid soil, and it thrives best in one composed of leaf peat and sand. The pine barrens of New Jersey afford just that kind of soil, with every variation in moisture from permanent bog to areas of pronounced aridity. The failure of earlier experimenters, and there have been several in the last 50 years, to establish an industry of blueberry culture was due primarily to their failure to recognize that an acid soil is the first essential of successful blueberry production. Before showing what has been done in the way of commercial blueberry culture in the pine barrens of New Jersey, it may be well to contrast an illustration of the Photograph from U. S. Department of Agriculture BLUEBERRY PLANTS, SHOWING THE BENEFICIAL EFFECT OF ACID SOIL AND THE INJURIOUS EFFECT OF RICH GARDEN SOIL The three large blueberry plants, one year old, were grown in a greenhouse in a peat soil. All three are over twenty-four inches high. Standing on the middle pot is a small glass pot containing a seedling of the same age and origin as the others, but potted in a rich garden soil. The difference in results shows the fundamental importance of a peaty acid soil for blueberry culture. greenhouse blueberry of 1911 with that of 1916, for the greenhouse and laboratory experiments have been the constant guide of the field plantation (see pages 538 and 539). While the largest individual berries have been grown in the greenhouses at Washington, the finest clusters and the best formed and most productive bushes have been reared outdoors in the New Jersey plantation. Furthermore, the field plants have reached the stage of commercial bearing at a much earlier age than was expected from observations on the greenhouse plants. In the article published in 1911 the conservative view was advanced that blueberry seedlings or cuttings would come into profitable bearing, under proper culture, in five to ten years. In the New Jersey plantation hybrid seedlings have borne their first commercial crop when only three years old and a crop three times as large when four years old. THE BLUEBERRY BUSH LIVES A MAN'S Under such favorable conditions as exist in the pine barrens, therefore, blueberry culture is to be classed, as to the age of first bearing, not with the slowfruiting apple orchard, but with the quick-fruiting peach, with this important difference, however, that while the peach tree remains in vigorous fruiting condition for comparatively few years, the blueberry bush, with suitable pruning, bids fair to last a man's lifetime and even longer. There was once pointed out to me by a man of sixty a handsome, vigorous blueberry bush which he had known from. his boyhood and which he said seemed to him just as large and vigorous then as now, and just as highly distinguished among all the blueberries of the region, for it was an albino bush and bore delicious white blueberries for the boys at the swimming-hole in his childhood just as it does today. Still further prospects of longevity does the wild blueberry possess. The tall decrepit veteran with densely interwoven and half-dead twigs and feebly moving sap in its old and rheumatic limbs has a means of rejuvenation which nature has not granted to the trees of the old apple orchard. If such an old blueberry bush is burned to the stump, there springs from its ashes a new bush, characterized Photograph from U. S. Department of Agriculture BLUEBERRY PLANT, SHOWING THE EFFECT OF COLD IN STIMULATING GROWTH The stem at the right was kept outdoors, through a hole in the glass side of a greenhouse, exposed to repeated freezing and thawing during the winter months. When spring came this outdoor stem burst into growth, as shown in the illustration; but the stem at the left, which was inside the warm greenhouse all winter, remained completely dormant. A knowledge of this influence of cold in stimulating the growth of the blueberry is of fundamental importance in the propagation of choice blueberries by cuttings. This illustration was published in the NATIONAL GEOGRAPHIC MAGAZINE for February, 1911, as an example of the fruit of a cultivated blueberry. These berries, reproduced in their natural size, were among the first that were produced on greenhouse plants. The plant itself was a seedling from a large-berried wild bush. not only by the symmetry and beauty of youth, but by youth's vigor and fruitfulness as well. The wild blueberry is the real and literal phoenix among fruits. BLUEBERRIES ARE AS DIFFERENT AS The development of a large-fruited blueberry is very desirable from the standpoint of the grower, for not only is the cost of picking much reduced, but the market price is much increased. One characteristic of the blueberry, however, is of far more importance than size, namely, flavor. When one buys blueberries in the market he gets a mixture of berries from many bushes, and the composite flavor is always good. It would be a mistake, however, to infer that the blueberries from all wild bushes are of good flavor. They are not. In selecting wild bushies bearing large and handsome berries, to be used as breeding stocks, it has been found that some wild blueberries are sour, others insipid, other rank or even bitter in taste. All bushes whose berries are devoid of sweetness and the special flavor that characterizes the most delicious blueberries are rejected for breeding purposes, however large or externally beautiful their fruit may be. It is confidently expected that the hybrids produced from such selected parents not only will average better in flavor than the wild berries, but that an occasional hybrid will excel in this respect the best wild berries that we know (see pages 540 to 543). The improved and cultivated blueberry will be above criticism as to the size of its seeds. All the large-seeded species of this class of berries belong to the true This cluster contains the largest blueberry produced up to the present time. It measured seven-eighths of an inch in diameter. A bud from the largest-berried plant thus far known was inserted on a very vigorous seedling stock, was forced to rapid and luxuriant growth in the greenhouse, and finally was made to produce these berries. They are shown in their natural size. huckleberries, and none of these has been used in the breeding experiments.* PROPAGATED BY CUTTINGS From the many thousand hybrids testing and to be tested in the New Jersey In the southern United States and in the Middle West blueberries are not ordinarily distinguished from huckleberries, but in New England the distinction is very clearly drawn. The name huckleberry is there restricted to plants of the genus Gaylussacia, the berries of which contain 10 large seeds with bony coverings like minute peach pits, which crackle between the teeth. The name blueberry is applied in New England to the various species of the genus Vaccinium, in which the seeds, though numerous, are so small that they are not noticeable when the berries are eaten. It is probable that the comparatively low estimation in which this fruit is held in the South is largely due to the lack of a distinctive popular name and the consequent confusion of the delicious small-seeded southern Vacciniums with the coarse large-seeded Gaylussacias. It is the culture of the small-seeded blueberries only, as distinguished from the large-seeded huckleberries, that is here advocated. trial plantation a few bushes bearing the best-flavored, largest, and handsomest berries will be selected for further propagation. Like selected varieties of apples, selected blueberries cannot be propagated successfully from the seed. They do not come true in that way. They do come true, however, when budded or grafted; but, as new shoots are continually springing up below the graft, these methods also cannot be applied satisfactorily to the blueberry. As early as 1909 it was appreciated that propagation must be effected by cuttings or some similar method, if a particular selected bush was to be perpetuated and increased on a commercial scale. The various methods followed by gardeners in the rooting of cuttings of ordinary plants were faithfully tried, but without success. Thousands of cuttings that started well drooped and died in the cutting beds. It became evident that new methods |