« AnteriorContinuar »
There are no statistics to show how great is the loss resulting from the impositions of unreliable seed firms, but it must be millions of dollars. The loss from sowing poor seed grown on the farm is also great. Frequently, especially among the uneducated classes, any wheat which is injured too badly for market purposes, either by such diseases as smut, or by improper harvesting or storing, is used for seed purposes. Many experiments with immature seed wheat have been made. While its germinating powers may be greater, the conclusion is that smaller and less vigorous plants are produced, resulting in a lower yield.1
It is very questionable whether wheat frozen in ripening, or burned in the stack or bin, can be safely used for seed. It certainly should not be sown if badly affected, and the only way to determine its value is by a germination test. A low germinating power often means a lack in quality as well as in quantity, which makes the use of such seed very hazardous.
Whether seed will "run out," and whether it is profitable occasionally to "change seed" or not, has long been a mooted question. A change of seed, especially if the change is between very distant sections, is almost invariably accompanied by some disadvantages. If it is merely a promiscuous exchange, as is so often the case, it is very likely that the disadvantages will greatly outweigh the advantages. The principles above pointed out throw some light on this question and show that there is one case in which a change of seed is advantageous, namely, from an environment unfavorable in certain conditions to one more favorable in these same conditions and having no new disadvantages which counterbalance the good results. It is obvious that if the transfer is from a favorable to an unfavorable environment, the wheat must, by a selective process, adapt itself to the new conditions before it can yield as much as that which is already adapted. This, of course, has reference only to the one variety which is under consideration. There are also other considerations, however. In the first place, the custom of changing seed is a costly one in actual expenditure of cash. Farmers purchase annually many thousands of bushels of seed wheat, paying fancy prices and freightage from distant points, and also paying duty on foreign varieties. Then, too, injudicious seed exchange is a source of weed and disease dissemination, as well as a powerful influence against proper methods of plant breeding. Selection cannot be successfully practiced in improving the quality of grain if the seed must be given up every few years for a strain grown upon other land.
1 Rept. N. D. Agr. Col., 1902, p. 32; Yearbook U. S. Dept. Agr., 1896, p. 306.
Nothing has been found in the principles of wheat development which would indicate that wheat "runs out," or deteriorates, if continually grown on the same farm under rational methods of culture. Undoubtedly, any seed may deteriorate because of injuries arising from disease, improper cultivation or selection of seed, or from many other causes which militate against the production of a normal type of kernel. Grass wheat formerly grown in Kansas is a case in point. Experiments at different stations have shown that seed may be sown on the same land for many years, and yet give no appearance of running out.1
The idea that a change in seed gives good results has always been founded more upon opinion than upon well ascertained facts. It was doubtless first advanced by Columella shortly after the Christian era, and has been widely held ever since. The most striking argument in favor of the idea is put forth by Darwin, who reasons that since a change of residence is of undoubted benefit to convalescents, it may be that a change of soil is advantageous for wheat. This is only reasoning by analogy, however, and involves the comparison of abnormal animal life with normal plant life, certainly not a strong argument at best. Some good authorities still hold that wheat will run out if sown continually on the same land.2 A great and preponderating amount of evidence has accumulated, however, to show that farmers should rely chiefly upon locally developed seed, and that they should give more attention to the production of their own seed. The importation of seed is profitable only when differences in the rigors of soil and climate exist. Such importations have greatly improved the standard of American wheats and have also extended the industry of raising them. Foreign wheats are one of the most important fac- 1 N. D. Bui. 17, p. 98.
'Saunders. Evidence 1903, p. 46; Kept. Kans. State Bd. Agr., Vol. 21, No. 81, p. 7.
tors in hybridization, supplying precisely those qualities in which American wheat is deficient.
So far the most valuable importations have been made from Russia. The now world famous red winter wheat grown in the section of which Kansas is the center was originally imported by the Department of Agriculture from the Crimea in Russia. So successful has it proved that in 1901 Kansas growers individually imported over 15,000 bushels of this variety for seed. Its superiority consists in higher yield, hardiness to winter cold, better milling qualities and great rust resistance. Four or five winter varieties obtained from eastern and southern Russia were tested by the department in 1901 and 1902. They were much hardier than any varieties grown in this country, and extended the winter wheat area farther north and west. The better Russian varieties are late in maturing, while, as a rule, Japanese sorts are early. Hybrids from the two ripen early and possess the good qualities of the hardy Russian sorts.
Drought-Resisting Durum varieties adapted to alkali soils have been introduced from Russia. They have proved themselves admirably suited to the region west of the 100th meridian, from Texas to Dakota, where wheat growing was supposed to be practically impossible. The area on which they may be grown is shown on the accompanying map.1
Some Hungarian wheats have also been introduced, as well as white wheats from Australia, Europe and the Orient, to obtain a higher grade of wheat with which to replace the deteriorating white wheat of California. The Weissenburg, a very promising variety from Hungary, is the source of the flour that sells on the Liverpool market for $1.00 more per barrel than any other flour.
The introduction of spelt and emmer must also be mentioned here, both for a crop and for hybridizing wheats. In all this work of introducing and breeding wheat, disease resistance is kept in mind, and some sorts remarkably free from rust have been procured. There are two needs which are common to the whole country. Greater yielding power is, of course, always desirable, and for one reason or another, the same is also quite generally true of earlier maturity, whether it is to escape drought, rust, insects or frost. The new environment may 1 See p. 48.
cause changes in the imported variety, and it may require several years to determine its merits.
Instead of scientific agriculture having "almost reached the limit of its development," it has just fairly begun to develop. This statement is especially applicable to the careful selection of seed. "In Germany, where the percentage of sugar in sugar beets is high, they deem it necessary to adopt the following plan to improve the standard. Ten thousand beets say, all perfect, are selected from a field where the choicest strain was sown and carefully tended. A small section is taken from each beet and tested to determine the percentage of sugar it contains. The hundred beets of the highest quality are selected and planted the next season for seed. The seed from these, is, of course, very valuable, representing hundreds of dollars worth of work, and it is used simply for growing seed beets. From the seed beets thus grown only one hundred of the best are again selected as stock to grow seed beets from, while the rest of the 10,000, though grown from the same strain of seed, are considered only good enough for growing seed for the man who raises sugar, and not sugar beet seed.''1 Seed which is good enough for growing beets for seed is considered much too valuable to use in growing beets for sugar. The beet grower has made more progress in this respect in one century than the wheat grower has in many centuries. It should, nevertheless, be said that the improvement in beets was partly the unforeseen result of European legislation. By a peculiar tax, whatever sugar above a certain per cent was extracted from beets paid no tax, or a smaller rate. To increase profits by increasing this excess proved such an additional stimulus to improve the sugar content of beets that the legislators apparently could not modify the laws fast enough to keep pace with the advance.1
While the past importance of introducing new varieties is conceded, it is said that "the time will soon arrive when there will be no further varieties to introduce better than we already have." Unquestionably, the breeding of wheat will have an increasing importance. As wheats may be developed, so they may deteriorate, on account of soil and climate, and in such cases there must perhaps be a periodical importation of seed.
"Proc. Tri-State Grain Grow. Ass'n. 1900, p. 170.
2 Handworterbuch der Staatswissenschaften, 7:997-1009.
The cultivation of wheat is coeval with agriculture itself. No land was alone the ground of Ceres where the human race learned to plow and sow, nor was it the task of any one race or nation to tutor mankind in the agricultural arts. How the nations of antiquity tilled, sowed and reaped would be of great interest, but the records which time has bequeathed to us are all but silent upon these homely topics.
Climatic Effects.—The soil in nature is more uniformly covered with vegetation throughout the year than it is under cultivation. Dark, exposed soil absorbs more heat than soil covered with vegetation. Thus cultivation is supposed to moderate climate and there is a widely prevalent opinion that it also lessens frosts, humidity and rainfall.
Plant and Soil Effects.—Soil alterations of the highest importance are made by means of tillage, fertilizing and irrigation. The resulting variations in wheat are quantitative rather than qualitative, except in the case of irrigation, which is practiced on a comparatively small part of the wheat area. This process and that of fertilizing are discussed in later chapters. Cultivation, as here used, refers only to the mechanical operations connected with raising wheat in the natural environment treated in the previous chapter. It renders this natural environment artificial to the degree in which it alters the mechanical arrangement of the soil in nature and eliminates from the competition of life other species of plants which would naturally compete with wheat in the struggle for obtaining the sustenance held by soil and atmosphere. This sets the wheat plant free from many natural conditions which tend to destroy unfit variations and to force wheat to assume one type. Thus cultivation, while it has no direct influence in increasing variation, by removing conditions which exert a selective influence, is indirectly the means by which a greater