Magazine of Horticulture 3(10): 361-363 (October 1837)
I. Ringing Fruit Trees; with a notice of some Results following its application to
the Pear Tree, discovered by M. Van Mons, of Brussels.
By A. J. DOWNING,
Botanic Garden and Nurseries, Newburgh, N. Y.
RINGING (incision annulaire, of the French,) is a well known operation, occasionally performed upon fruit trees, both with a view of inducing fruitfulness, and of hastening the maturation of fruits. The practice is one of very ancient origin, but was revived among the moderns by Du Hamel, who published the result of his very successful experiments in the Memoire de l'Academie des Sciences, for 1778. Since that period it has been in a considerable degree resorted to in England, to force the production of blossom buds on sterile fruit trees, and to hasten the period of ripening of fruit already formed, as well as to increase its size. When practised for the former purpose, the operation must be performed in the spring; but when it is intended that the effect shall be produced upon the fruit of the current year's growth, the incision should be made when the branch is in flower.
Ringing is easily performed at the proper season, when the vegetable juices are in full flow, by passing a knife completely around the branch twice, and taking out a complete circle of outer and inner bark, not, however, larger (from a half to three quarters of an inch,) than the tree can easily replace in two or three years, as otherwise it would lead to the premature death of the branch. Although much practised by amateurs, ringing has scarcely proceeded upon any certain rules until of late, and we have recently been highly pleased to learn, by the Annals of the Paris Horticultural Society, that the eminent pomologist of Brussels, Professor Van Mons, has turned his attention to this subject, and, as usual, has added very considerably to our stock of information respecting its effects.
Professor Van Mons has confined his experiments chiefly to the pear, and announces that he has discovered two new consequences attending the application of ringing upon this tree, the chief of which is the great stimulus given to the growth of the branch operated upon, accelerating its development, both in length and circumference, as well as a more rapid subdivision of branches.
M. Van Mons, in selecting branches for ringing, gives the preference to those situated upon middle-sized pyramid or quenouille formed trees, and, also, to such as are at least equal in size to those surrounding them. The incision is made upon a branch about two inches in diameter, in order that it may be furnished with the greater number of buds. The year following, when the wound has partially healed, the branch will be found to have acquired double the size of its neighbors, the next year triple, the succeeding one quadruple—and so on in succession, until the branch, operated upon, by its greater rapidity of growth, eventually takes the place of the stem, when the influence of the operation gradually ceases. The fourth season the cicatrice is so complete, that the wound is only to be distinguished by a few wrinkles. It is necessary, in order that the branch operated upon may experience this superior acceleration of growth, that it should be one of the principal shoots which has a direction nearly perpendicular, or but little oblique. Those which have an upright growth, parallel to the main stem, have of course an advantage over the oblique ones. Ringing does not appear to produce any acceleration of growth in the vegetation of horizontal shoots, the vigor remaining the same in the untouched branches as in that operated upon. This latter lengthens slowly, with but little extension of branches, but all of its lateral buds come into a fruiting state. The wound is longer in healing in the horizontal branches, and the crops are as liable to fail as upon the other branches; whilst upon the perpendicular branches operated upon, M. Van Mons has never witnessed a complete failure of fruit, even in the worst and most unfavorable seasons.
At the fourth, or, at the latest, the fifth year, the branches upon which the incision has been made, and which have been subject to the artificial acceleration of growth, resume again that state of natural luxuriance common to the rest of the tree, while they are not more liable to blight or disease than the other branches. At the same time when the branches operated upon return to a natural state, those which are below the incision come into bearing; but the fruit produced by the latter is yet small, harsh, and greatly inferior,—two years after it will probably equal in quality that borne by the branches subjected to the incision.
The second effect which M. Van Mons found to follow from the process of ringing the pear tree, and which he considers not the less valuable from the number of applications which, may be made of it, is the power which it has of preserving the vitality and vigor of the branches operated upon, when, from any sudden disease, as the blight, &c., the tree is liable to perish. M. Van !Ions has witnessed a number of illustrations of this interesting fact in one of his own gardens, where the soil, of only about a foot in depth, rests upon a stratum of ochreous, gravelly sand, which has never been moved. The roots of the trees no sooner penetrate this layer of sand, than the extremities of the branches are attacked by blight; but the branches on which ringing has been practised entirely escape, as if this operation had established a direct relation between them and those roots not in contact with the layer of sand.
M. Van Mons, from his experiments in ringing different species of fruit trees, has been led to the conclusion that it is calculated to be of much more benefit to the pear than any other fruit. On stone fruits, as the peach, &c., the wound caused by the necessary removal of the bark, gives rise to an exudation of gum, and the branch, in consequence, after, dies. From the comparative facility, and abundance, too, with which these trees produce flower-buds and fruit, the effects which result from annular incision are scarcely desirable. On the apple it appears to cause the production of a great number of shoots between the wound and the trunk of the tree, without scarcely at all increasing the fruitfulness of the branch.
The full effect of this operation, M. Van Mons believes, can only be experienced by grafted varieties, or trees reared from stocks which have already borne fruit. It appears to have but little or no effect in forcing seedlings into a bearing state, before the period of fruitfulness fixed by nature. Recent experiments have also proved, that the annular incision, practised upon large roots, influences the tree much more uniformly, and its effects are much more durable, than when performed upon the branches.—A.J.D.
We commend the above article, by our correspondent, to the attention of our readers. The operation of ringing fruit trees is but little performed in this country, and the principle upon which it is practised not generally understood. It may be, however, very beneficially made use of to bring into a fruiting state trees, particularly pears, which ordinarily would not for a very long period produce fruit, without this operation was performed either upon the roots or the branches. The French amateurs and gardeners, who are au fait in every thing connected with the subject, practice the ringing of their fruit trees to a great extent.—Cond.