This section is from the book "The Gardener's Monthly And Horticulturist V22", by Thomas Meehan. See also: Four-Season Harvest: Organic Vegetables from Your Home Garden All Year Long.
Read before Penna. Fruit Growers' Association, Jan. 22d, 1880.
I am well aware that this question is easier asked than answered. There are no doubt various causes of unproductiveness, but I wish to call the attention of fruit growers to a custom that may have such effect. I apprehend nothing else than to be pronounced heterodox on pomology,; but as orthodoxy is sometimes forced to change base, it may be counted in as orthodox some day. It is also true, that it is easier to controvert a theory than to prove or establish it. Has it ever occurred to nurserymen and fruit growers, that the cutting of scions from nursery rows for root grafting for a succession of years tends to strengthen simply wood growth, and at the same time weakens the tendency to productiveness, or at least retards it? I refer more particularly to apples and pears, as peaches frequently form fruit buds in nursery rows one year old from bud; the departure therefore can not be so great as in some other fruits. For the sake of counter argument I will admit that the custom of cutting scions from nursery rows has been practiced for many years, but at the same time a large proportion of scions has also been taken from bearing trees, hence the difficulty of proving such a theory if it were correct. To test this question thoroughly would require many years of experimenting.
Experience has taught nurserymen that scions cut from young thrifty trees, whether in nursery or orchard, when grafted will make more vigorous trees than when taken from old bearing trees.
Fruit growers also know that generally the most vigorous growers are more tardy bearers than those of slow growth. We know very well that some varieties bear earlier than others, but it must be admitted that not unfrequently trees of the same variety purchased from the same nursery, and planted in the same orchard side by side, at the same time, do not make uniform growth nor bear uniform crops. That there should be uniformity in every respect could hardly be expected, but the results are oftimes as opposite as of two varieties; one will go into fruiting early, while another is tardy; or one will bear regular crops, while another will bear only alternate years.
Now, there must be a cause, or causes for all this. Is there any other theory more plausible to account for these differences? There are numerous instances in both vegetable and animal kingdoms which confirm the theory of variations in nature. Take for instance all the present varieties of maize, wnich doubtless descended from one parent, of which there are now possibly more than a hundred, and yet many so unlike each other as they well could be made, and still all retain the original character so far as it can be traced back. It is conceded that the comparison is not quite fair where changes are produced by seed selection. But take the potato, which can, and has been materially changed by selection of tubers. For instance by selecting such as ripen earliest for a term of years, we may have the same variety earlier than the original. The same effect will be produced in an inverse ratio by selecting seed from such as ripen latest. The potato may also be changed in other respects by selecting for seed the roundest or longest for a succession of years, or select seed from stocks that have tubers of most uniform size, or any other desirable character, and a fixed type may eventually be obtained of just what is desired.
When we glance over the great variety of shrubs and flowers originated from sports, and established as new varieties, which have by proper selection for a term of years become fixed so as to retain their identity, we must conclude that from some cause nature is at times turned out of its regular course in producing its like; and when once turned out, the stock or plant may by designed selection for a series of years never again resume its former character.
This line of argument might be continued indefinitely in the vegetable kingdom. The laws which govern the animal kingdom are in a great measure analagous to those which govern the former. The changes and improvements that have been made with domestic animals is truly astonishing: for instance with sheep, cattle and hogs; to accomplish which required time, perseverence and judicious selection.
We, as poraologists, must admit that although much has been accomplished in our line, breeders of domestic animals have made greater strides in theirs. In animals, as in vegetables and fruits, all the most desirable qualities have never yet been produced in one individual. The stock breeders who have aimed to produce beef animals have established the Shorthorns. Those who aimed for richest milk and butter production, have their ideal in the Jerseys and Guernseys; while those who had in view milk and cheese production, have established the Holsteins and Ayreshires. At the same time other fancy points in those breeds were sought and obtained, and fixed types established. For instance in the Durhams, roan or red colors and small horns: in the Jerseys, fawn or black colors, black tongue and black wisp. In the Ayreshires the color must be white and brown, or white and red; while the Holstein would be ruled out as bogus if not strictly white and black. Numerous other points have been bred into fixed types by selection, and except an occasional sport, with almost as much certainty as a good mechanic will produce a desired piece of furniture.
If we could place some of the early specimens of cattle from which those improved breeds have descended, side by side with the latter, the contrast would be marked indeed: or when we compare the ancient land-shark or alligator hogs with the present Chester Whites, Berkshires and Poland China pigs, the resemblance is not at all striking. The former were simply scavengers, just what nature intended them to be, while the latter are almost worthless for such purposes. Great progress has been made in producing new fruits and flowers by hybridization and cross fertilization, which is however not altogether germain to the question under consideration: but that the graft influences the root in nursery rows, every intelligent nurseryman knows. And that by grafting upon large trees the reverse is sometimes shown will hardly be denied. If, then, these are facts, may there not be other influences at work which we do not yet understand. May not this continual grafting from non producing trees weaken the fertility of the trees thus grafted, that when they arrive at bearing age, the least unfavorable conditions will injure the fruit in its embryotic and early stages so as to prevent its perfection.
If we understood all the laws which govern the animal and vegetable kingdoms, they would no doubt develop facts not dreamed of in our philosophy.