in Seed Growing p. 19-26 (1896)
SELECTION IN ITS RELATION TO SEED GROWING
C. L. ALLEN, New York
[read before the Seedsmen's Session of the World's Fair Horticultural Congress, Chicago.]
SELECTION, from the seedsman's standpoint, means more than a choice of samples, or more even than a preference of types in the various classes of vegetables or flowers, whether it is in regard to shape, size, color, or in its relation to earliness or lateness in development, as may be desired. Neither has it any connection with the popular theory of what is known as ''natural selection," "the survival of the fittest,'' that active principle of evolution which was cradled in the fertile mind of that distinguished philosopher, De Lamarck, and by the late Charles Darwin developed into the "origin of species."
To the seedsman selection is not a cause, but an effect, and in its application to his business it is of vital importance; in fact, it is the foundation upon which the superstructure of business success is completed. In the development of a type, selection is the principal agent employed, but doubly important is its office in preserving a type after it is secured. There are two separate and distinct principles in selection, and the two are antagonistic; they are both methodical, but for entirely different purposes. In the one instance we select with a view of the greatest possible increase in seed production, and in the other just the opposite. In our cereals selections are made to produce the greatest amount of seed with the least possible amount of straw. To that end, in the best wheat-growing sections, the longest and best filled heads are carefully selected; and those, too, in which the grains are the heaviest for seed purposes. The seed thus saved is given every possible aid to reproduction by growing it on soil best adapted to its development; by giving each plant sufficient room to grow strong, rather than tall; and by furnishing plant food proportionate to its necessities. At the proper time, if the same careful selection is again made and the same care in cultivation given, there will result another marked improvement, both in size and productiveness of the grain. This operation oft repeated will establish a type superior to that from which the first selection was made. To preserve that type the same care must be given that was necessary to produce it.
The same rule holds good in the selection of Indian corn, an important work that is generally overlooked. It is the common practice to select the best ears for seed at the time of husking, which is a step in the right direction; yet this practice is attended with many disadvantages, and does not, as a rule, accomplish the purpose intended. In this method the largest ears are selected, of which there is usually but one ear on a stalk; besides, there is no certainty about selecting such ears as ripen at the same time, which is a matter of great importance. It is possible for a weak plant to produce a large ear, and it is very common for a plant of bad habit to do so. It is but natural to suppose that the grains of stunted and sickly corn, even though the ears may attain a large size, necessarily partake of the weak constitution of the plant that produced them, and that to reproduce from such would only be to encourage bad habits. For this reason ears should be selected before the stalks are cut, choosing those on which there are two well-formed ears on the stalk, which should be of low growth and well furnished with leaves, and the ears set near to the ground. The whole plant should, by the length and breadth of the leaves and the vigor of the stalk, indicate perfect health. Earliness should always be combined with productiveness; therefore, the first ears to ripen, when all other conditions are favorable, are the ones to select in the line of improvement. All should be gathered at the same time, in order that there may be uniformity in ripening, united with earliness, which is of the greatest importance in developing a variety.
This may suffice to show the method of selection, where the object is to produce the greatest amount of perfectly developed grains or seeds from a given acreage, to be employed as food. With this object in view it is needless to state that nearly all seeds will reproduce themselves more freely if sown as quickly as possible after maturity. This is shown plainly by the way weeds reproduce themselves, the seeds of which are sown as soon as ripened. But in selection for vegetables, where seeds are only used to reproduce the plant, the opposite course must be pursued, and forms must be chosen that produce as little seed as possible. This is particularly noticeable with the English-grown cucumbers, which are, from nature's standpoint, degenerate forms, as they do not reproduce themselves except by artificial fertilization. This comes from their having been grown for a long series of years under unnatural conditions.
All species of the natural order, Cucurbitaceae, to which the cucumber belongs, finds a congenial home in warm climates and on dry soils. The farther they are removed from these conditions the less seed they will produce, and the vitality of which will be proportionately lower. At the same time nature is always true to her first principle, self-preservation. To that end greater protection is given to the germs of future generations.
The outer covering of seeds is for their preservation or protection while in the infant state, and at maturity these coverings dry up or decay and disappear. These coverings are adapted by nature to the plant's necessities; if but little protection is required, only little will be given. With all vine seeds, the less seed there is produced the greater is its value for the production of the crop, as the flesh is the part consumed; and it invariably follows that the greater amount of the one, the less there will be of the other. Therefore, the best fruits of the vine family are those with the least or lowest reproductive qualities. Gardeners with keen observation note the fact that the older melon, cucumber, and squash seeds, are—without having lost their germinating power—the better, as the proportion of flesh to the seed is greater, and the vines are more productive of fruit and less inclined to throw out branches. The older the seed the lower is its vitality, and the greater is nature's effort to preserve it. As the careful mother doubly protects the feeble child against cold, so Mother Nature protects the seeds of low vitality with extra covering. The melon has more flesh when grown from old seed, because of its low vitality.
The same is notably true with the egg plant, which is a native of North Africa and the East Indies. In these warm climates the fruit grows from four to five inches in diameter, and abounds with seed, filling the flesh nearly to the rind. As its cultivation extends northward the fruit increases in size, while the amount of seed diminishes. Thus, Nature guards her productions by enlarging the pericarp or fruit, in order that the seeds may be better protected against cold, which would destroy their vitality. The variety known as the New York Improved Purple, grown from seeds raised as far north as New York City, yield a crop, both as regards size and quantity, far in excess of the plants grown from seeds produced in the Southern States. The reason for this is obvious. Nature, being a strict economist, does not work in the interest either of the seedsman or the market gardener. Her object and sole aim is to preserve and perpetuate the species; and when the plant has furnished the proper amount of seed nothing further is required of it. If a plant grown in a temperate climate produces in a single fruit only one-fourth the quantity of seeds which it usually yields in a warm climate, it follows that four times the number of fruits must be produced to accomplish the desired result. And this is what the egg plant does at the North, when raised from Northern-grown seed. As before stated, plants from Northern-grown seed produce more fruit but less seed; so, too, is the seed less vigorous. Long Island-grown seed will rarely test above sixty in germinating, when fresh; besides, nearly all Northern-grown seeds of this variety of egg plant are small and shrunken, while that grown at the South is large and plump, and will invariable give a more satisfactory test of germination. As is the case with many other kinds of vegetables, the conditions that are favorable for the production of the fruit are unfavorable for the production of good samples of seed and a yield satisfactory to the grower.
A more familiar illustration of this principle may be seen in the history of the development of the cabbage. Changes in form, through climatic influences, are shown to have been greater in this than with any other vegetable. In a wild state the parent of our cultivated forms of cabbage has but few leaves, which are loosely arranged, but all that are necessary to protect the germ of the coming season's growth, which is to produce seed for the perpetuation of the species. When taken to a colder climate more protection becomes necessary. This is furnished by additional leaves, which are of a finer texture and more compactly arranged. The result of this care is the solid heads of our present varieties of cabbages. From two or three distinct types introduced from Holland early in this century a large number of varieties, more or less distinct, have been produced wholly by careful, and, in many instances, systematic selection. To more clearly illustrate this principle let us note some of the points in the development of forms, where the cabbage is grown to the greatest perfection. Long Island is probably the most congenial home of the cabbage to be found in this or any other country. Nowhere else is it so generally grown or of a better quality. And here is where the greatest number of truly distinct varieties have originated. There is probably a greater variety of soil to be found in close proximity here than in any other part of our country. On the one side is a heavy but friable loam, capable of producing enormous crops. On the other side it is of a light, sandy character, with but little recuperative strength. Intermediate is, in sections, a turfy and sandy loam, and beneath all is a gravelly subsoil, a condition best suited for cabbages.
In most countries there are certain districts and some particular farms which are famous for the production of some special crop and where the same is extensively cultivated. In such localities there are usually to be found some men who are leaders in their principal industry; they are regarded as authorities and their advice is taken on all matters that pertain to their calling. This is the case on Long Island in regard to cabbage, where certain farmers possessing a remarkable degree of intelligence, and who are close observers and thinkers as well as workers, have made the growing of cabbage a speciality. These men have made selection as a choice in regard to form and habit a study. They have chosen for a purpose, either as regards earliness or lateness, or for the development of a desired form. Persistent labor and watchful care in this direction have been the means of producing the best strains or varieties of cabbage in cultivation.
While variations of climate produce wonderful changes in vegetable forms, it is a well-established fact that any vegetable grown in a given soil will assume a very different form when grown on either a heavier or a lighter one. This has been shown in a remarkable degree with the cabbage. A given variety grown for a long number of years on a heavy soil, with a liberal supply of plant food, proper care in growing the plants and in transplanting them, and constant cultivation until the crop is matured, will develop a type remarkable for size and vigor, with excellent keeping qualities, and be what is known as a Late Flat Dutch or Drumhead cabbage. On the other hand, take the same stock seed, grow it on a light sandy soil, under the same climatic influences, with the same care in cultivation, always selecting with a view to earliness and solidity and the result will be in the same number of years a variety of the same general form but of smaller size and very much earlier. Again, a soil intermediate in character, from the same stock, during the same period, with the same care in selection, will give a variety intermediate in character as well as in period of growth. Under such conditions have been produced the several varieties introduced from Long Island.
It is an established principle in agriculture that a sandy soil is favorable for an early growth, and a heavy soil for a continuous growth. Early and late, large and small, varieties are not to be expected from the same soil and under the same conditions of growth, both natural and artificial. It must of necessity take a longer time to grow a head of cabbage weighing twenty pounds than one half the size. I have thus far spoken of the development of the cabbage by selection under natural conditions, but there are other methods employed by the specialists. These are of an artificial character and have been material helps in selection. When these specialists harvest their stock seed they examine each plant carefully before cutting it, and if the seed is of large size it is rejected, because they hold that such seeds will make leaves instead of heads. Besides that, these men will not use seed until it is at least three years old; for the same reason they will not use large seed. This statement corroborates my assertion "that the conditions favorable for the production of the fruit are unfavorable for the production of a good sample of seed." I may, however, add that a handsome sample is not always a good sample, always excepting instances, as in the cereals, where the seed is the part consumed.
In the whole list of garden vegetables there is none so susceptible to improvement as the tomato; none better pays good attention; none shows neglect more quickly, both in quantity and quality of fruit. It is, moreover, capable, by careful selection, of the highest development, and will as quickly deteriorate if the same care in selection that was given to produce a variety is not continually employed to preserve it. It is generally supposed that the varieties have a natural tendency to deteriorate, which makes it necessary to be constantly on the watch for new varieties, which have their parentage in cross-fertilization and are developed by selection. This theory is both absolutely true and wholly false, although this statement may seem paradoxical. I have endeavored to show the marked effect upon vegetable growth of climatic influences, together with the character of the soil. But the tomato is more sensitive to change than any other vegetable with which I am acquainted, and it is more erratic, too, than any other. On my own grounds I have had the Ignotum, since its first introduction, and with me it is the most perfect and most desirable of any of the vast number of varieties. It is perfectly smooth, of good size, ripens evenly and well up to the stem, the substance is more solid than that of most others and is perfectly tender. An intelligent grower in this section has given it special attention for seed purposes, and it continues to grow in favor. From the same seed bed for the past two seasons plants were taken a distance of ten miles and grown on nearly the same character of soil, and under precisely the same conditions of climate, while the cultivation in the two sections was alike of the highest order, but here this variety was a total failure; the fruit was deeply ribbed, irregular in shape, ripened irregularly, and the vines grew in all manner of ways, produced but little fruit, and this was worthless. Mr. Hallock, the successful grower, states that he has heard similar reports from other sections.
On the other hand, during the past two years I have visited two gardens, at least one hundred and fifty miles apart, where since the Trophy was first introduced no other variety has been grown, and during the twenty-five years this variety has constantly grown in favor. The fruits are more even in size and shape; they ripen up to the stem perfectly, and, what is more important, they ripen to the center and produce but little seed. A fault with this tomato when first introduced was that it did not ripen to the center, which was invariably a little hard.
These two instances are related to justify my assertion that there is and is not a natural tendency toward deterioration. What they may or may not be depends wholly upon circumstances. This theory being established, what is the lesson ? Plainly, that, especially for seed purposes, the tomato should never be grown excepting under conditions where, with good cultivation, it will remain true to type. That there is a great difference in varieties in this respect cannot be questioned. For instance, where the Ignotum signally failed the Trophy and the Favorite were both satisfactory. This is one of the difficulties the seedsman has to encounter, and for which there is no preventive. But there is one thing he does or should know—viz., the price usually paid the grower is not in harmony with the principle of selection, but rather the actual cause of deterioration. Difficult as the problem may be of solution, it is evident that the best directed efforts are not always crowned with success, and that the best possible selection for a given locality may be disappointing in another.
Few vegetables show so great a change in their eating qualities as our sweet corn. There are, relatively, but few localities where it reaches its limit of perfection. Selection of place, to secure the best, is quite as important as to select with the view of an improved type. It is poorest when grown on a light, sandy soil, and best when grown in a moderately heavy loam and disintegrated shale. To show how the soil affects quality, take an ear grown in Connecticut, its congenial home, and plant one-third of its grain on the sandy soil of Long Island, one-third on the heavy soil, and the remainder where it grew, and there will be three distinct qualities. The same grown but a few years in the southern sections of our country develops a distinct and worthless type as a vegetable. What is true of the vegetables mentioned is true of all others, which shows the importance of selection in all its phases.
It has often been demonstrated that when any given type has been developed by selection, either rapidly or slowly, under favorable conditions of soil and climate, it will as rapidly revert when grown under reversed conditions. It is also true that any form that will materially revert when grown under changed conditions for a few years will proportionately change in one year. This will, in a measure, account for the deterioration of varieties where the stock seed has been grown under different conditions from where the type originated. In most instances one year's growth will not materially change a type, but in all cases where a type is to be preserved it requires the same care in selection and cultivation and other conditions under which it originated.
Many persons maintain that a renewal or change of seeds is absolutely necessary. This may or may not be so. All depends upon circumstances. In a locality where a certain type can easily be kept up and improved by selection a change of seed is not only unnecessary, but unwise, and the only safe course to pursue is to procure stocks from a locality where it reaches the greatest perfection—it matters not whether it be in our own State, country, or continent.
In a country so vast and varied as ours, where the setting sun of the East is the rising sun of the West; where in the North there is rarely a month without a frost and at the South rarely a month with one; where the soil in one locality is the most productive, in another the reverse, and this same, too, in close proximity—the seedsman has difficulties to contend with that are entirely unknown in any other country. He must have a knowledge of selection sufficient to enable him to choose from every section of country such types as are best adapted to its various conditions of climate and soil. This is no easy task when, as demonstrated, varieties show such marked changes, when grown but a few miles apart, apparently with the same climatic influences, and where there is but little difference in the character of the soil. The aim of the seedsman is to procure the best quality at the least possible cost, but in their efforts competition is an antagonistic force that is quite apt to counteract the best motives.