These facts help us understand how a change could occur in a variety of red clover if its seed is produced in a region where days are too short to induce all the plant types in the variety to flower.

TEMPERATURE also must be considered in seed setting. Some forage species require an exposure to low temperatures before they will flower.

Varieties of red clover, which contain germ plasm from mammoth or single-cut types, require exposure to low temperatures before they will produce normal bloom. Among them are Dollard, Lakeland, LaSalle, and the Finnish Tammisto. Genetic shifts occur in such varieties when seeds are harvested before the plants have been exposed to overwintering temperatures.

H. A. Steppler and L. C. Raymond, of Macdonald College in Canada, reported a marked change in the relative proportions of plant types in LaSalle red clover when seeds were harvested in the fall following a spring seeding. A similar change was reported for the Tammisto red clover when seeds were harvested from a seeding-year stand. The percentage of rosette-type plants was 33 percent in the original Tammisto seeds, but only 13 percent in the seeds harvested from the seeding-year stand. Seeds from the 2-year-old stand were similar to true Tammisto seeds.

Thus, to minimize changes that may occur in varieties containing single-cut plant types, it is necessary to avoid production of seeds from seeding-year stands and to limit the increases in southern latitudes to one generation.

Most of the cool-season forage grasses require much the same environmental conditions for floral development as the single-cut red clover varieties do. Selected plants from these species, however, will flower to some extent without exposure to low temperatures. Thus a variety of grass may consist of a mixture of plant types. Some plants would require exposure to definite low temperatures. In others, low temperature would increase greatly the amount of flowering. The rest of the plants would not be affected.

An example of this varied response was observed in a variety of orchard-grass made by combining four parental plants (clones) adapted to the Eastern States. Tests were established with vegetative propagations at Prosser, Wash. (46 latitude); Logan, Utah (41 latitude); and Shafter and Tehachapi, Calif. (35 latitude).

The four clones were similar in flowering habit in Washington and Utah. There was a difference of 6 to 7 days in flowering between the earliest and latest clones. The flowering habit at Tehachapi, Calif., was like that in the northern locations, except that the late clones flowered 15 days after the early ones. The difference at Shafter was 23 days. At all four locations, the same clones were consistently the earliest flowering and the latest flowering.

Similar flowering responses were noted in another four-clone variety of orchardgrass grown at each of the four places. The greatest differential in flowering response was found at Shafter, where the early- and the late-flowering clones were 39 days apart.

Shafter and Tehachapi are at approximately the same latitude but differ greatly in seasonal temperatures. The plantings at Shafter were in the southern part of the San Joaquin Valley at an elevation of 352 feet; the plants were limited in their exposure to freezing temperatures. The plantings at Tehachapi were on a mountain plateau at an elevation of 4 thousand feet. Freezing temperatures occur there anytime after early September.

The floral response of the clones in these two synthetic varieties of orchardgrass illustrates the effect of temperature and daylength in regulating flowering in many grasses. It is important therefore that precautions be taken to grow the seeds of orchardgrass and other grasses that have similar responses in conditions that will minimize differences in flowering among the various plant types (genotypes) in a variety.

Alfalfa is equally responsive to variations in the environment, even though its floral response differs from that of the grasses or red clover.

Dale Smith and L. F. Graber, of the Wisconsin Agricultural Experiment Station, were the first to direct attention to the differences in height of Ranger plants, grown from seeds produced in Arizona and Montana, during the fall of the seeding year. Under the shortening autumn days in Wisconsin, the average height of fall regrowth was unmistakably taller in the plants from Arizona-grown Ranger seeds than from the Montana seeds. Differences in plant height from seeds increased for a second generation in the southern latitudes were even more pronounced.

In another study, foundation and certified seed lots of Vernal alfalfa produced in nine States and two Canadian Provinces were compared at Lafayette, Ind. Many of the foundation seed lots produced a larger number of taller plants than the check samples (breeder seed) provided by the originator of the variety. However, most of the certified seed lots increased in the Northern States and all those from the Southwest produced taller plants than the foundation seed from which they were grown.

A shift toward taller plants appears to be more pronounced in Vernal than in Ranger perhaps a reflection of the greater diversity in germ plasm used in breeding the Vernal variety.

The changes or shifts in varietal characteristics could destroy the superiority of the variety if they were allowed to continue from generation to generation. The seed-production practices for many of the forage varieties therefore must be regulated to keep the changes to the minimum. When the approved procedures are followed, seeds produced outside a variety's region of adaptation give forage yields equal to that grown within the region.

In forage tests comparing the four classes of certified seed, breeder, foundation, registered, and certified seed, of Atlantic, Buffalo, Ranger, and Vernal varieties of alfalfa, no significant differences in yields of hay were found among the various classes of certified seed or among seed lots from different parts of the country.

A collection of 25 lots of breeder, foundation, and certified seed of Vernal was included in a test of hay yield at Lafayette. There were no significant differences in yields, even though some of the foundation and certified lots were known to have a higher percentage of tall plants than the breeder seed.

A series of tests with Atlantic, Buffalo, and Ranger alfalfa at 12 State agricultural experiment stations showed no significant differences in hay yields among the breeder, foundation, registered, and certified seed classes. Likewise, there was no difference in yields between certified seed produced within and outside the varieties' regions of adaptation.

A plan for the increase of seeds of varieties outside their regions of adaptation must provide for a limitation on generations of increase; the exclusion of management and cultural practices that will have abnormal effects on growth, flowering, and seed-setting habits; the control of volunteer plants; and adequate isolation from other fields of the same crop.

The seed-certification standards include the essential requirements to safeguard against serious genetic shifts in forage crop varieties. Thus the production of seeds in different regions has had no major effect on the performance of forage crop varieties a heartening proof of the soundness of the seed-certification system.

The successful production in the Western States of legume seeds for use elsewhere has been followed with interest in other countries. The Organization for European Economic Cooperation developed a similar system for increasing seed supplies for its member countries.

Northern European countries encounter the same problems in growing legume seeds as we do in the Central and Eastern States. Weather is frequently unfavorable for good pollination, development of seeds, and harvesting.

Under OEEC sponsorship, alfalfa varieties from Austria, Germany, Sweden, and the United Kingdom were multiplied in France, Greece, Italy, Portugal, and Turkey. Varieties of red clover from Belgium, Germany, the Netherlands, and Norway were increased in France, Greece, Italy, Portugal, and Turkey. Sweet lupines from Denmark, Germany, and Sweden were grown in Greece and Portugal. Vetches from Denmark, Germany, and Sweden were reproduced in Greece, Italy, Portugal, and Turkey.

Seeds of each variety produced in the different countries were planted in "growing-on-tests" by the Danish Seed Testing Station at Copenhagen to determine whether genetic changes had taken place in the varieties during the seed-multiplication process.

The control plantings showed no visible differences between the alfalfa seed lots increased in the southern European countries and the basic foundation seed from which they were grown.

Some of the red clover seeds were earlier in flowering and less vigorous than the parent seeds.

Plants of the lupine varieties grown from seed produced in the southern countries did not deviate from the control sample. The same was true for the vetches, except for an occasional seed lot that produced plants that were shorter, earlier flowering, and lighter green than those grown from the basic seed.

CARLTON S. GARRISON is Leader, Seed Production Investigations, Forage and Range Research Branch, Crops Research Division, Beltsville, Md.