Working Farmer 1(4): 62-63 (May, 1849)
The Van Mons Theory
A. J. Downing, Esq.
Dr. Van Mons, Professor at Louvain, devoted the greater part of his life to the amelioration of fruits. His nurseries contained in 1823, no less than two thousand seedlings of merit. His perserverance was indefatigable, and experimenting mainly on Pears, he succeeded in raising an immense number of new varieties of high excelence. The Beurré Diel, De Louvain, Frederic of Wurtenberg, &c., are a few of the many well known sorts which are the result of his unwearied labors.
The Van Mons theory may be briefly stated as follows:
All fine fruits are artificial products; the aim of nature, in a wild state, being only a healthy, vigorous state of the tree, and perfect seeds for continuing the species. It is the object of culture, therefore, to subdue, or enfeeble this excess of vegetation; to lessen the coarseness of the tree; to diminish the size of the seeds; and to refine the quality and increase the size of the flesh or pulp.
There is always a tendency in our varieties of fruit trees to return by their seeds towards in wild state.
This tendency is most strongly shown in the seeds borne by old fruit-trees, And "the older the tree is of any cultivated variety of Pear," says Dr. Van Mons, “the nearer will the seedlings, raised from it, approach a wild state, without however ever being able to return to that state."
On the other hand, the seeds of a young fruit tree of a good sort, being itself in a state of amelioration, have the least tendency to retrograde, and are the most likely to produce improved sorts.
Again, there is a certain limit to perfection in fruits. When this point is reached, as in the finest varieties, the next generation will more probably, produce bad fruit, than if reared from seeds of an indifferent sort, in the course of amelioration. While, in other words, the seeds of the oldest varieties of good fruit mostly yield inferior sorts, seeds taken from recent varieties of bad fruit, and reproduced uninterruptedly for several generations, will certainly produce good fruit.
With these premises, Dr. Van Mons begins by gathering his seeds from a young seedling tree, without paying much regard to its quality, except that it must he in a state of variation; that is to say, a garden variety, and not a wild sort. These he sows in a seedbed or nursery, where he leaves the seedlings until they attain sufficient size to enable him to judge of their character. He then selects those which appear the most promising, plants them a few feet distant in the nursery, and awaits their fruit. Not discouraged at finding most of them of mediocre quality, though differing from the parent, he gathers the first seeds of the most promising and sows them again. The next generation comes more rapidly into bearing than the first, and shows a greater number of promising traits. Gathering immediately, and sowing the seeds of this generation, he produces a third, then a fourth, and even a fifth generation, uninterruptedly, from the original sort. Each generation he finds to come more quickly into bearing than the previous one, (the fifth sowing of pears fruiting at three years,) and to produce a greater number of valuable varieties; until in the fifth generation the seedlings are nearly all of great excellence.
Dr. Van Mons found the pear to require the longest time to attain perfection, and he carried his process with this fruit through five generations. Apples he found needed but four races, and peaches, cherries, plums, and other stone fruits, were brought to perfection in three successive reproductions from the seed.
|*"I have found this art to consist in regenerating in a direct line of descent, and as rapidly as possible an improving variety, taking care that there be no interval between the generations. To sow, to re-sow, to sow again, to sow perpetually, in short to do nothing but sow, is the practice to be pursued, and which cannot be departed from; and in short this is the whole secret of the art I have employed."—Van Mons' Arbres Fruitiers, l-p. 223.|
It will be remembered that it is a leading feature in this theory that, in order to improve the fruit, we must subdue or enfeeble the original coarse luxuriance of the tree. Keeping this in mind, Dr. Van Mons always gathers his fruit before fully ripe, and allows them to rot before planting the seeds, in order to refine or render less wild and harsh the next generation. In transplanting the young seedlings into quarters to bear, he cuts off the tap root, and he annually shortens the leading and side branches, besides planting them only a few feet apart. All this lessens the vigor of the trees, and produces an impression upon the nature of the seeds which will be produced by their first fruit; and, in order to continue in full force the progressive variation, he allows his seedlings to bear on their own roots.*
Such is Dr. Van Mons' theory and method for obtaining new varieties of fruit. It has never obtained much favor in England, and from the length of time necessary to bring about its results, it is scarcely likely to come into very general use here. At the same time it is not to be denied that in his hands it has proved a very successful mode of obtaining new varieties.
It is also undoubtedly true that it is a mode closely founded on natural laws, and that the great bulk of our fine varieties have originated, nominally by chance, but really, by successive reproductions from the seed in our gardens.
It is not a little remarkable that the constant springing up of fine new sorts of fruit in the United States, which is every day growing more frequent, is given with much apparent force as a proof of the accuracy of the Van Mons theory. The first colonists here, who brought with them many seeds gathered from the best old varieties of fruits, were surprised to find their seedlings producing only very inferior fruits. These seedlings had returned by their inherent tendency almost to a wild state. By rearing from them, however, seedlings of many repeated generations, we have arrived at a great number of the finest apples, pears, peaches and plums. According to Dr. Van Mons, had this process been continued uninterruptedly, from one generation to the next, a much shorter time would have been necessary for the production of first rate varieties.
To show how the practice of chance sowing works in the other hemisphere, it is stated by one of the most celebrated of the old writers on fruits, Duhamel of France, that he had been in the habit of planting seeds of the finest table pears for fifty years without ever having produced a good variety. These seeds were from trees of old varieties of fruit.
The American gardener will easily perceive, from what we have stated, a great advantage placed in his hands at the present time for the amelioration of fruits by this system. He will see that, as most of our American varieties of fruit are the result of repeated sowings, more or less constantly repeated, he has before him almost every day a part of the ameliorating process in progress; to which Dr. Van Mons, beginning de novo, was obliged to devote his whole life. Nearly all that it is necessary for him to do in attempting to raise a new variety of excellence by this simple mode, is to gather his seeds (before they are fully ripe,) from a seedling sort of promising quality, though not yet arrived at perfection. The seedling must be quite young—must be on its own root (not grafted;) and it must be a healthy tree, in order to secure a healthy generation of seedlings. Our own experience leads us to believe that he will scarcely have to go beyond one or two generations to obtain fine fruit. These remarks apply to most of our table fruits commonly cultivated. On the other hand, our native grapes, the Isabella, Catawba, &c., which are scarcely removed from the wild state, must by this ameliorating process be carried through several successive generations before we arrive at varieties equalling the finest foreign grapes; a result, which, judging from what we see in progress, we have every reason speedily to hope for.
In order to be most successful in raising new varieties by successive reproduction, let us bear in mind that we must avoid—1st, the seeds of old fruit trees; 2d, those of grafted fruit trees; and 3d, that we have the best grounds for good results when we gather our seeds from a young seedling tree, which is itself rather a perfecting than a perfect fruit.
It is not to be denied that, in the face of Dr. Van Mon's theory, in this country, new varieties of rare excellence are sometimes obtained at once by planting the seeds of old grafted varieties; thus the Lawrence's Favorite, and the Columbia plums, were raised from seeds of the Green Gage, one of the oldest European varieties.
Such are the means of originating new fruits by the Belgian mode.
Weston: Selective Breeding — Theorie Van Mons (1836)