IMPROVEMENT
OF TIMOTHY

MORGAN W. EVANS, Associate Agronomist, Division of Forage Crops and Diseases, Bureau of Plant Industry

TIMOTHY is the common name applied to the species Phleum watense L. About 10 species in the genus Phleum are known, timothy neing the only one under cultivation. They are all native to northern Europe and Asia with one exception. This one, a native in North America, is Phleum alpinum L., alpine timothy—a grass that occurs throughout the mountainous regions in the western United States, and in the East as far south as the White Mountains of New England (20, p. 122).

   While timothy is of European origin, it was in the United States that it was first brought under cultivation. The early history of the crop in this country is somewhat obscure, but mention of it in colonial days is not uncommon. In New England it was known as herd’s grass at least as early as the first part of the eighteenth century—probably earlier. The name “timothy” is said to have been derived from Timothy Hansen, who obtained seed from New England or New York and introduced it into Maryland, and possibly into some of the other southern Colonies, about 1720. Sometime after 1740 an early agrituralist, Jared Elliott, sent seed from Connecticut, under the name of herd’s grass, to Benjamin Franklin. In a letter dated July 16, 1747, Franklin wrote that the grass sent to him “is grown up and proves mere timothy"—indicating that it had become fairly well established as a hay crop in Pennsylvania at that time (21). From then on the crop increased in use and importance and has received more attention from agriculturists than any other grass.

In 1909, according to the United States census report, there was a total of 34,228,000 acres of timothy grown alone and in mixture with clover. In 1929 this acreage had decreased to 25,547,000, but it still constituted 37.7 percent of the total acreage used for the production of all kinds of hay in that year. In 1928, the last'year in which separate estimates were made by the United States Department of Agriculture of the acreage of timothy alone and in mixture with clover, timothy was grown alone on 8,537,000 acres and with clover on 16,078,000 additional acres.

   For feeding horses, of which there are still large numbers, no other hay has been found as generally satisfactory as timothy. The cost of the seed is less than that of most meadow and pasture grasses and it can be sown more readily with the implements used for sowing clover and alfalfa. Although alfalfa produces hay superior to timothy in yield and in percentage of protein, timothy grows well on many soils on which alfalfa or even clover cannot be produced without a considerable investment for lime or drainage. Timothy is very extensively grown for hay in mixture with clover, and alfalfa can be more readily grown on some soils not naturally suited to it if it is sown in mixture with timothy. As a pasture grass, timothy is more palatable to livestock than many other grasses, including redtop, orchard grass, and Kentucky bluegrass; and the recent increased interest in pastures has created an interest in the possibility of developing varieties of timothy especially adapted for use in pasture mixtures.

According to available information, the first efforts to develop improved strains of timothy were made in the United States. No improved varieties were in existence at the close of the last century, as there were of corn, oats, wheat, and other crops. The appreciation of the wide diversity in timothy plants, which made varietal improvement possible, and the prospect of benefits to the producers of timothy hay, -both for market and for use on the farm, if varieties were available that would produce larger yields of better quality than ordinary timothy, created incentives for the breeding programs that were undertaken at this time by several experiment stations and other agricultural organizations.

Willet M. Hays, professor of agriculture at the University of Minnesota (fig. 1), made in 1889 a number of selections of timothy plants. He had observed the wide variation in plants of ordinary timothy and thought that by selecting the best from among them it would be possible to develop varieties, suited for growing in mixture with clover, that would prolong the season when timothy could be harvested in condition to make a high grade of hay, and also varieties capable of producing larger yields (13).  No records have been found of any earlier attempt to improve timothy in this way, although Sinclair recorded the development of varieties of perennial ryegrass, through selection, more than a century ago (23, pp. 212-213). Hays discontinued his own work with timothy, but afterward, as the first secretary of the American Breeders’ Association and as Assistant Secretary of the United States Department of Agriculture, he took an active interest in the improvement of this crop.

Figure 1.—Willet M. Hays, the earliest breeder of timothy.

   In 1894, a few years after Hays made his first selections, A. D. Hopkins (fig. 2), then entomologist at the West Virginia Agricultural Experiment Station, selected a number of timothy plants at his farm at Kanawha Station, W. Va. (14, 15, 16). He continued this work for several years, making new selections and conducting tests of them, for the purpose of eventually producing varieties with better quality and higher yielding capacity than the single unimproved strain then available. In 1899 he distributed plants of some of his selections to the Department of Agriculture and to a number of State agricultural experiment stations. In 1902 he became forest entomologist and chief of the Division of Forest Insects, Bureau of Entomology, Department of Agriculture, but continued his work with timothy on his farms in West Virginia. About 1907 or 1908 he transferred additional selections he had made to the Division of Forage Crops of the Department.

Figure 2.―A.D. Hopkins who developed the first varieties of timothy of which plants and seed were distributed.

   Hopkins increased the stock of seed of three of his selections and introduced them as new varieties.  Seed was distributed by him and by the Department to a number of farmers and experiment stations. One of these varieties, Hopkins Early, headed and bloomed at somewhat more nearly the same time as medium red clover than ordinary timothy and thus was better for growing in mixture with this clover. Stewart Mammoth, derived from a vigorous, long-stemmed plant, was slightly later and was thought capable of producing somewhat larger yields than ordinary timothy. The third variety, Pasture timothy, did not differ greatly in habit of stem growth from the ordinary strain used for hay, but its leaves tended to remain green late, and, as its name suggests, it was thought well suited for pastures.

   One of the cooperators to whom A. D. Hopkins distributed plants or seed was T. F. Hunt, of the Ohio State University. When Hunt went to the College of Agriculture at Cornell University, Ithaca, N. Y., in 1903, he immediately began a timothy-breeding program. His objective was the development of varieties that would give a larger yield of superior-quality hay, and he also wished to study some of the fundamental principles upon which a timothy-breeding program should be based. Seed was obtained from a large number of sources in the United States and from foreign countries. Plants were grown in row test plots, and from them many variants were obtained as the basis for further selections. When Hunt went from Cornell University to the University of California, the timothy-breeding investigations were continued by H. J. Webber and his associates. At the present time, the timothy-breeding work at Cornell is under the direction of C. H. Myers. A number of technical studies of timothy, the variations occurring in it, and methods of improving it have been described in different published articles.  Two varieties have been developed at Cornell, and efforts are now being made to have seed of them introduced commercially. One is somewhat earlier than ordinary timothy; the other is later and produces relatively large yields; both tend to be rust-resistant.

During the period from 1911 to 1924 the Iowa Agricultural Experiment Station tested about 300 timothy selections. Seed of the most outstanding one of these was increased and distributed to Iowa farmers, but the strain was finally lost. In Minnesota the early work started by Hays in 1889 was later discontinued, but in 1916 work was again resumed by others. Early work in timothy improvement was also conducted at the Pennsylvania station, starting in 1908, but was discontinued in 1931. Other stations that have more recently carried on work in timothy improvement are those of Kentucky, New Jersey, and Wisconsin.

The earliest timothy-breeding work conducted by the United States Department of Agriculture was undertaken in 1899 by F. Lamson-Scribner, Chief, and Thomas A. Williams, Assistant Chief, of the old Division of Agrostology, with tests of some of the selections received from A. D. Hopkins, then at the West Virginia Agricultural Experiment Station. When the Office of Forage Crops—now the Division of Forage Crops and Diseases—of the Bureau of Plant Industry was organized in 1903, C. V. Piper, who was in charge, became interested in timothy improvement. From that time until 1909 a number of new selections of leafy, vigorous timothy plants were made. Tests were conducted at the Arlington Experiment Farm, Arlington, Va., of the new selections in comparison with some of Hopkins’ selections, and also in comparison with selections obtained from the New York (Cornell) Experiment Station. The timothy-improvement program, however, did not receive a very great amount of attention until a decade later when the Timothy Breeding Station was established in cooperation with the Ohio Agricultural Experiment Station. This work was conducted first at New London, Ohio. It continued from 1909 to 1915, when the station was reestablished on a larger area of land at North Ridgeville, Ohio. Here the work was conducted until 1935, when it was transferred to the Ohio Agricultural Experiment Station at Wooster. The outstanding varieties developed in this work are Huron and Marietta, described later under the heading Improved Varieties.

Since the breeding of timothy was first undertaken in the United States, similar work has been conducted in Canada and in several countries in Europe.

   Some of the earliest European work was done at the Plant Breeding Institute at Svalof, Sweden. Several varieties have been developed there, some of which are adapted to different regions, as southern Sweden, middle Sweden, and northern Sweden, where winter hardiness is an essential characteristic.

Timothy-breeding investigations were undertaken at the Welsh Plant Breeding Institute at Aberystwyth, Wales, somewhat later than at Svalof, and have been conducted on an extensive scale.  Varieties suitable for hay production in Great Britain have been developed from native timothy plants. Other varieties, characterized by relatively small low-growing plants with procumbent stems that tend to become rooted at the nodes, have been found of value in pastures in Great Britain especially when grown in mixture with white clover. A third type of timothy, midway between the typical hay-producing type and the extreme pasture type, classified as “hay-pasture” timothy, also has been developed. The methods used in timothy breeding at Aberystwyth have been described by Jenkins (7).

Timothy-breeding investigations are also being conducted at agricultural experiment stations in Scotland, Belgium, Denmark, Germany, the Union of Soviet Socialist Republics, and possibly elsewhere.

   It is comparatively easy to develop, within a few generations, a strain of timothy in which some single character, such as earliness or lateness, long stems, freedom from rust, or tendency to produce large yields, is reproduced fairly well in the plants grown from seed. To produce a variety in which all of the desirable characteristics are combined is a much more difficult task. Furthermore, a certain variety of timothy may be adapted only to a more or less restricted area. For instance, in northern Sweden the Bottnia variety is valuable because it is very winter-hardy, but in northern Ohio it apparently has no practical value because it produces smaller yields of hay than other varieties that are sufficiently hardy in this latitude. Some of the late varieties that have produced relatively large yields of high-quality hay in northern Ohio are of no value in Kentucky or farther south. It is therefore necessary to have varieties for certain regions as well as for different uses, and this must be recognized in any well-formulated breeding program.

The most common disease of timothy is rust. Although plants in meadows are not often entirely destroyed by it, yet the growth of those that are badly attacked is checked, and the leaves dry up prematurely. Some plants are more susceptible than others. Selection for rust-resistant strains has been one of the objectives of most breeders of timothy. When plants relatively free from rust have been selected, it has been found that their progeny tend to be rust-resistant.  In an investigation conducted at MacDonald College, Quebec, Canada, Bird (2) found that, generally speaking, the majority of improved strains of timothy tested showed marked resistance to rust. Although strains differed greatly in their reaction to the disease, the reaction of individual plants within strains also varied greatly. No strains were found entirely free from the disease. Strains from Scandinavia were generally highly susceptible to rust, yet Gloria and Øtofte, two improved varieties, were outstanding in their resistance.

   Some of the earliest public discussions of the possibility of producing improved varieties of timothy, as of other farm crops, took place at the meetings of the Society for the Promotion of Agricultural Science attended by many of the leading agricultural scientists of the last decade of the past century and of the first decade of the present one.  A great deal of interest was aroused by Hopkins’ papers on the improvement of timothy. He described many variations, such as early plants in condition to cut for hay about the same time as red clover and late plants producing hay that would retain green leaves and high quality for a longer time than ordinary timothy, and showed the possibilities for developing distinct varieties.  Here, it seemed, was a new field of opportunity for service to agriculture. At the meeting at Columbus, Ohio, in 1899, Hopkins said that because of the pressure of official duties he thought he would have to give up his work with timothy. W. J. Beal, of the Michigan Agricultural College, one of the leading American botanists of that time, and also others protested that Hopkins should rather give up his work with insects in order that he might be able to devote all of his time to the improvement of timothy.

The present interest in improved pasture grasses has developed within the last 10 years.

As already noted, pasture varieties of timothy already have been developed and introduced in farm practice by some of the European agricultural experiment stations or plant-breeding institutes. When sown in fields to be used as permanent pastures, these varieties continue to form a better and more persistent turf than ordinary timothy.

At the New York Agricultural Experiment Station (Cornell), excellent results have been obtained with Aberystwyth Pasture timothy S.50 when grown in association with wild white clover under conditions of close grazing.

In general, these low-growing European types of timothy produce very little seed in the latitude of Ohio; for normal development they require the longer days in spring and summer that occur farther north. If they are used, it may be necessary to have the seed produced relatively far north, either in North America or in Europe, and to import it into localities where it is to be sown in pastures.

Long before any of the special pasture varieties of timothy were introduced, ordinary unimproved American timothy had been used for pasturage. Farmers in the United States very commonly turn their farm stock into meadows during late summer or fall, after the first hay crop has been removed. It is also a common practice to utilize timothy meadows from which hay crops have been harvested as all-season pastures for 1 or more years before plowing for some other crop.

   It, is not unlikely that some of the improved varieties of timothy, elected primarily for their usefulness in meadows, may also be superior ordinary timothy for use in pastures.

   Ordinary American timothy plants vary within quite wide limits in season of maturity, length and degree of fineness of stems, breadth of leaves, degree of susceptibility to rust, tendency for the leaves to remain green as the seeds approach maturity, and in other ways.  These numerous variations and the different ways in which they are combined in different plants result in a very wide range of variants from which selections may be made.

In Europe, as in the United States, wide variation in timothy plants is common and some of these variants offer special opportunity to the breeder. A form occurs in extreme northern Europe that is entirely distinct from any found in the United States. Plants of this form grown in the latitude of northern Ohio are characterized by short stems, which usually grow more or less procumbent upon the surface of the soil (fig. 3) instead of upright like the stems of ordinary American timothy (fig. 4). Relatively few of the stems have heads, the florets bloom late, and the seed frequently does not form or fails to mature. Some of the more extreme plants of this northern European form produce no heads when they are grown as far south as northern Ohio.

Figure 3.—A timothy plant of the pasture type grown from seed from northern Europe.


METHODS OF DEVELOPING NEW VARIETIES

   Timothy is generally cross-pollinated. Experiments have demonstrated, however, that when pollen from the same plant is used to (fertilize the florets, usually a small percentage of them produce seed.

   Cross-pollination results in the occurrence of many natural hybrids between plants of diverse types. This provides a wealth of forms from which selections may be made, but makes the maintaining of a new variety more difficult.

The method used in the timothy-improvement work conducted by the Department in cooperation with the Ohio Agricultural Experiment Station is as follows:
   Seed from single-plant selections is sown in a seedbed or in a small broadcast plot. The growth of the plant of different selections is observed and compared in these plots, and plants are taken from them and transplanted to cultivated row plots where each individual plant has ample space for development. Later, from the row plot of each strain, one or more new selections are made of the plants most outstanding for the desired qualities. When, as a result of repeated observations and tests, a selection of sufficient merit is finally developed, the supply of seed is increased, and it is introduced under an appropriate name as a new variety.

   Since no provision is made during the early stages of selection to prevent the florets of the plant or plants of one selection from becoming fertilized with the pollen produced by plants of other strains, the method is known as that of selection with open pollination. Experiments conducted over a number of years have shown, however, that when selection for some particular quality or character is continued through several generations plants may be developed that reproduce themselves through seed fairly true for this character (6).

Figure 4.—A timothy plant having the relatively long, upright stems characteristic of the American forms.

At some other experiment stations or plant-breeding institutions the seed of selected plants has been produced from self-fertilized florets, that is, florets fertilized with pollen from the same plant.  In this way it is possible to develop selections or varieties in which the plants conform to a certain type more closely than if they grew from seed produced under open pollination. In some strains of timothy this uniformity is attained only at the cost of much loss in vigor. Our general knowledge of the science of plant breeding indicates that this deterioration may be overcome later by artificially cross-pollinating two established uniform strains and producing a hybrid in which some of the most desirable characteristics of both parents are combined.

At other places where timothy breeding is being conducted both open-pollination and self-pollination are used, one method sometimes alternating with the other from generation to generation.

   When a variety of timothy is finally established and its seed is being increased and produced on a larger scale, it is essential that indisdiscriminate cross-pollination with ordinary timothy or other varieties be avoided, or else the peculiar characteristics by which the variety is distinguished are likely to disappear.

   Though no improved timothy varieties were available at the close of the past century, at the present time there are a number that are as distinct from one another as varieties of corn, oats, or wheat.

   Among those available commercially in the United States are Shelby, Huron, and the recently developed Welsh pasture strain, of which very limited quantities of seed have been imported from Great Britain within the last 2 or 3 years.

In other countries, additional varieties, mentioned in table 1 in the appendix, have been introduced.

The Shelby, an early-maturing variety grown in southern Indiana for many years, apparently is the result of regional selection. William Zoebel, of Shelbyville, Ind., producer of the variety, grew his own timothy seed from about 1855 until the time of his death in 1892, and his two sons continued the practice. Most of the Shelby timothy grown on other farms in the vicinity can be traced to the Zoebel farm.  The relative time of maturity of this timothy when William Zoebel began growing it is not known. The information available, however, indicates that the characteristic of earliness developed gradually by natural selection. Zoebel harvested his timothy for hay when the earliest heads were mature. Some of the seeds from the ripe heads shattered in the mow, or where the hay was thrown down to the floor below. The mixed chaff and seed was swept up and the seed was separated with the fanning mill. This process, which was repeated year after year and continued at least up to 1930, supplies an explanation of the origin of the variety that is satisfactory and may be assumed to be correct. Little or none of the seed is shipped away from the vicinity. Many farmers of the district who do not produce their own seed purchase seed of Shelby timothy if it is available. If it is not they get seed of ordinary timothy from somewhere else. Thus the early variety and ordinary timothy have been grown on different farms in the same locality, but Shelby timothy has retained the characteristic of earliness.

Figure 5—The six plants at the right, grown from seed produced by the original plant of Huron timothy, are more uniform and are more vigorous and larger than the six plants of ordinary timothy at the left.

In 1911 the plant from which this variety originated was found growing along a road near Wakeman, in north-central Ohio. It was transplanted to the timothy breeding station at North Ridgeville where it was grown in experimental tests. Seed was later distributed to agricultural experiment stations in other States. In the Pacific Northwest, in nearly all trials, the yields have been larger, the plants have remained in condition to make a good quality of hay later in the season, and they have continued to grow for a longer time in pasture mixtures than ordinary timothy. The Huron is now most extensively grown in northeastern California and western Oregon, though it has been found well-adapted to unirrigated land in northwestern California and western Washington, as well as to the irrigated and moister valleys of eastern Oregon, eastern Washington, and northern Idaho.  The use of the variety, especially in pastures in mixture with other grasses and clovers, has been gradually expanding. It was estimated at the Oregon Agricultural Experiment Station early in 1936 that, in addition to its being used on several hundred acres seeded to this variety alone, it has probably been sown in pasture mixtures on at least 8,000 to 10,000 acres.

Another selection developed at the timothy breeding station, North Ridgeville, Ohio, is about to be introduced under the varietal name Marietta. In northern Ohio it is 4 or 5 days earlier and in southern Ohio about a week earlier than ordinary timothy. Tests have demonstrated that it yields more than ordinary timothy, especially in the latitude of southern Ohio. It arrives at a stage of development suitable for cutting for hay at more nearly the same time as medium red clover or alfalfa than does ordinary timothy. The Ohio Seed Improvement Association is planning to assist in the introduction of Marietta timothy into farm practice in those parts of the State to which it is well adapted.

Since the primary objective in most timothy-breeding programs is increased hay production, most of the improved varieties developed to date are primarily hay varieties.  Some of them, like that shown in figure 6, A, are earlier than ordinary timothy. One of the characteristics of an early timothy is that it is capable of producing elongated stems with heads, and the florets bloom and seeds form on them under shorter days than are required for late varieties, such as the one in figure 6, B. For this reason, early varieties can produce a hay crop in the South, where the days during spring and summer are too short for the proper development of late varieties. Trials in southern Ohio and at the Kentucky Agricultural Experiment Station have demonstrated the correctness of the theory that near the southern border of the timothy-producing area in the United States early varieties produce materially larger yields of hay than late varieties.

Figure 6.—A, A plot of early timothy, full-headed and beginning to bloom; B, a plot of late timothy, with stems grown to only a part of their full length. Photographed at North Ridgeville, Ohio, June 20, 1933.


DISTRIBUTION OF IMPROVED VARIETIES

In Sweden certain organizations formed for the purpose of introducing the seed of new and improved varieties of all kinds of farm crops have been instrumental in having some of the new varieties of timothy grown. No organized effort of this kind has yet been made on a large scale in the United States.

At Cornell University and in Ohio seed has been distributed to farmers who expect to harvest a seed crop. The same method is used in Ontario, Canada. In Quebec the seed is sent to the Provincial seed farm and from there to Provincial seed centers. In Great Britain improved strains are now being grown on a commercial scale by seedsmen. In Sweden all seed is sold and distributed by the Svalof Seed Co., which has a monopoly on all varieties produced by the Swedish Seed Association.

The increased cost of seed must always be taken into consideration in the establishment of new crop varieties. The seed of improved varieties of timothy necessarily sells at a somewhat higher price than that of ordinary unimproved timothy. This is because the seed grower must use extra care not to have any ordinary timothy plants growing in mixture where seed of the improved variety is being produced. Further, if the seed is certified, the cost of inspecting the meadow must be added. However, the total quantity of timothy seed required for establishing 1 acre of meadow is so small that the slight additional cost for the improved seed should be no objection if the varieties are distinctly superior.

Since relatively long days are required for their development (7), it appears probable that the usefulness of late varieties of timothy will be restricted to latitudes no farther south than the northern part of Ohio (8). When grown under suitable conditions, it has been found that the better late varieties produce somewhat more hay than ordinary timothy, though usually these increases in yield per acre do not exceed a few hundred pounds. The leaves on the best late selections remain green for a longer time than those of ordinary timothy, and consequently the protein content and quality of the hay remain at a relatively high level for a longer time. On farms in the northern part of the United States, where relatively large acreages of clear timothy hay are harvested and where there is difficulty, because of unfavorable weather conditions or the pressure of other farm work, in harvesting ordinary timothy early enough to produce hay of a high quality, late varieties would have certain advantages.

Timothy is now being grown in mixture with alfalfa in an increasing area each year (7). This mixture should be harvested early, before ordinary timothy has begun to bloom. It is apparent, therefore, that an early variety of timothy, that would be in bloom when the crop should be harvested, is most suitable for such a mixture and should be supplied by the timothy breeder.

No varieties of timothy that are primarily pasture types have yet been produced in the United States. The Welsh pasture variety, seed of which is now available to a limited extent, is characterized by its short, low-growing stems, and it would produce much smaller yields of hay than any of the hay types. There has been so little experience in this country with the European pasture varieties, even experimentally, that it is not yet clear just how useful they may be.

As indicated in the preceding paragraphs, the principal objectives in the improvement of timothy are the development of rust-resistant varieties; early varieties suited to the southern part of the timothy- growing area; late varieties for the North, for use where timothy meadows are maintained for 2 or more years; varieties adapted for hay production when grown in mixture with clover or alfalfa; and varieties for use in pastures.

When T. F. Hunt began the timothy-breeding investigations at Cornell University in 1903, seed was procured not only from many different places in the United States and Europe but also from other countries. The plants grown from these lots of seed revealed the existence of a very wide range of types (26). Some of the strains at Cornell were used by Clark (3) in a technical study of variation and correlation in timothy. Smith and Myers (24) have recently published the results of a biometrical analysis of yield trials.

Investigations at MacDonald College on the rust resistance of improved strains have been previously referred to.

Gregor and Sansome (10) found that the low-growing forms of timothy plants with more or less procumbent stems, which occur in Great Britain, have 14 chromosomes (2n), whereas the plants with longer, more nearly upright stems have 42 chromosomes (6n). Plants of the latter type, which occur both in Europe and in North America, were designated by these authors as the “American" and the low-growing forms as “British Wild" type. Gregor at first found these two types are intersterile (9), but according to a recent report (18) they later were able to produce artificial F₁, hybrids between them.

Sethi, in a study conducted in India of Phleum, Phalaris, and Festuca, found seven as the basic chromosome number in each genus (22). In Phleum, while different morphological types interbreed quite readily provided they have the same number of chromosomes, diploid and hexaploid types can be crossed only with great difficulty.

At the Plant Breeding Station at Svalöf, Sweden, Muentzing (19) observed and studied spontaneous hybrids between Phleum pratense and P. alpinum (4n). Some of these hybrids were approximately pentaploid.

The extent to which timothy florets produce seeds under conditions self-pollination has been studied by Witte (27), Valle (25), and other European investigators. In general, it has been found that when they are self-pollinated the average percentage of florets producing seeds is very much less than under natural conditions that permit cross-pollination.

A series of genetic studies of timothy has been conducted at the Minnesota Agricultural Experiment Station. Hayes and Barker (11) found that there is a considerable amount of variation in the extent to which timothy may be self-pollinated. Some plants are highly self-sterile, others are highly self-fertile. Clarke found that although a few of the selfed lines were markedly reduced in vigor the majority compared favorably in yielding ability with the open-pollinated commercial strains (4). He observed that when timothy seeds are produced by self-fertilized florets for a few consecutive generations the plants grown from these seeds are more uniform than plants grown from seed from open-pollinated florets.

Hayes and Clarke, in an investigation conducted at the Minnesota Experiment Station (12), found that selection in self-fertilized lines is a logical means of freeing the lines of undesirable recessive characters and of obtaining vigorous lines that excel in such important characters as yielding ability and disease resistance. On the other hand, it has also been found elsewhere (6) that when selection for any particular type is continued, even under natural conditions favorable for open pollination, the plants of many strains representing several generations of selection show a high degree of uniformity.

 (1)  Bachtell, M. A., ALLEN, H., and Monroe, C. 1934. ALFALFA-TIMOTHY HAY FOR THE DAIRY FARM . . . Ohio Agr. Expt. Sta. Bull. 538, 41 pp., illus.
 (2)  Bird, J. N. 1934. INFLUENCE OF RUST INJURY ON THE VIGOUR AND YIELD OF TIMOTHY, Sci. Agr. 14: 550-559, illus.
 (3)  Clark, C. F. 1910. VARIATION AND CORRELATION IN TIMOTHY (PHLEUM PRATENSE L), N. Y. (Cornell) Agr. Expt. Sta. Bull 279, pp. [3011-350, illus.
 (4)  CLARKE, S. E. 1927. SELF-FERTILIZATION OF TIMOTHY. Sci. Agr. 7: 409-439.
 (5)  Evans, M. W. 1933. Huron TiMoTHY. U. S. Dept. Agr. Leaflet 99, 5 pp., illus.
 (6)  ―1936. SELECTION OF OPEN-POLLINATED TIMOTHY. Jour. Amer. Soc. Agron. 28: 389-394, illus.
 (7)  ―and Allard, H. A. 1934. RELATION OF LENGTH OF DAY TO THE GROWTH OF TIMOTHY. Jour. Agr. Research 48: 571-586, illus.
 (8)  ―Allard, H. A,, and McConkey, O. 1935. TIME OF HEADING AND FLOWERING OF EARLY, MEDIUM, AND LATE TIMOTHY PLANTS AT DIFFERENT LATITUDES. Sci. Agr. 15:573-579.
 (9)  GREGOR, J. W. 1931. EXPERIMENTAL DELIMITATION OF SPECIES. New Phytol. 30:204-217, illus.
(10)  ―and Sansome, F. W. 1930. EXPERIMENTS ON THE GENETICS OF WILD POPULATIONS. II PHLEUM PRATENSE L. AND THE HYBRID P. PRATENSE L. X P. ALPINUM L. Jour. Genetics 22: [373]-387, illus.
(11)  Hayes, H. K., and Barker, H. D. 1922. THE EFFECTS OF SELF-FERTILIZATION IN TIMOTHY. Jour. Amer. Soc. Agron. 14: 289-293.
(12)  ―and CLARKE, S. E. 1925. SELECTION IN SELF-FERTILIZED LINES AS A MEANS OF IMPROVING TIMOTHY. Sci. Agr. 5: 313-317, illus.
(13)  Hays, W. M. 1892. IMPROVEMENT OF TIMOTHY. Minn. Agr. Expt. Sta. Bull. 20:[45]-46.
(14)  Hopkins, A. D. 1895. SOME OBSERVATIONS ON VARIETIES OF TIMOTHY. Soc. Promotion Agr. Sci. Proc. 16: 29-33, illus.
(15)  ―1899. PROGRESS IN THE STUDY AND IMPROVEMENTS OF VARIETIES OF Timothy. W. Va. Agr. Expt. Sta. Rept. 12: 33.
(16)  ―1906. BREEDING TiMoTHY. Amer. Breeders Assoc. Proc. 2: 95-99.
(17)  Jenkins, T. J. 1931. THE METHOD AND TECHNIQUE OF SELECTION, BREEDING AND STRAIN-BUILDING IN GRAssEs. Imp. Bur. Plant Genetics, Herbage Plants, Bull. 3: 5-34, illus.
(18)  Jones, R. P. 1936. THE SWEDISI SEED AssociatioN. Herbage Rev. 4: 32-34.
(19)  MUENTZING, A. 1935. CYTO-GENETIC STUDIES ON HYBRIDS BETWEEN TWO PHLEUM SPECIES. Hereditas 20: 103-136, illus.
(20)  PIPER, C. V. 1914 FORAGE PLANTS AND THEIR CULTURE. 618 pp., illus. New York.
(21)  ―and Bort, K.S. 1915. THE EARLY AGRICULTURAL HISTORY OF TIMOTHY. Jour. Amer. Soc. Agron. 7: 1-14.
(22)  Sethi, B. L. 1932. A STUDY OF SOME SPECIES AND TYPES OF PHLEUM, PHALARIS AND FESTUCA WITH REGARD TO CHROMOSOME NUMBERS AND BREEDING PROPERTIES. Indian Sci. Cong. Calcutta Proc. 19: 312-313. [Abstract in Expt. Sta. Rec. 70: 757.]
(23)  SINCLAIR, G. 1824. HORTUS GRAMINEUS WOBURNENSIS . . . 438 pp., illus. London.
(24)  Smith, H. F., and Myers, C. H. 1934. A BIOMETRICAL ANALYSIS OF YIELD TRIALS WITH TIMOTHY VARIETIES USING ROD ROWS. Jour. Amer. Soc. Agron. 26: 117-128.
(25)  Valle, O. 1931. UNTERSUCHUNGEN UBER DIE SELBSTSTERILITAT UND SELBSTFERTILITAT DES TIMOTHES (PHLEUM PRATENSE L.) UND UBER DIE BINWIRKUNG DER SELBSTBEFRUCHTUNG AUF DIE NACHKOMMENSCHAFT EINE ZUCHTUNGSMETHODISCHE STUDIE. Suomen Maatalonst. Leuran Julk. (Acta Agralia Fennica) No. 24, 261 pp., illus.
(26)  Wesser, H. J., with the collaboration of Hunt, T. F., GiLmore, J. W., Clark, C. F., and FRASER, S. 1912. THE PRODUCTION OF NEW AND IMPROVED VARIETIES OF TIMOTHY. N. Y. (Cornell) Agr. Expt. Sta. Bull. 313, pp. 338-392, illus.
(27)  Witte, H. 1915. OM TIMOTEJEN, DESS HISTORIA, ODLING OCH FORMRIKEDOM SAMT OM FÖRÄDLINGSARBETENA MED DETTA VALLGRÄS PÄ SVALÖF. Sveriges Utsädesför. Tidskr. 25: 23-44, 143-191, 199-230, illus. [In Swedish. German summary, pp. 222-230.]