SEVERAL hundred varieties of grasses and legumes comprising more than 125 species have economic importance in the United States.

They differ in performance and in their requirements as to soil and climate. At least one variety is adapted to each use and to each particular site or location. Grasses and legumes therefore are an important part of the cropping system on nearly every farm.

Permanent stands of grasslands, including hayland, pastures, and ranges, comprise about a billion acres in the United States.

The various species are grouped as perennials, biennials, and summer and winter annuals. The longer lived species generally have the widest range.

Alfalfa is most widely grown of all cultivated forage species, primarily because of the success of plant breeders in developing numerous varieties that differ markedly in growth response, cold endurance, and persistence.

We estimate that 8 to 10 percent of our grasslands are planted each year to replace acreages on which either a grass crop has passed maturity or is plowed under as a phase of crop rotation. For replanting those acreages and seeding other land, nearly 1 billion pounds of seeds are needed annually.

A highly specialized seed-production industry is essential to assure domestic supplies of seed that have the specific superior genetic characters that differentiate the recommended varieties one from another.

Several developments have caused shifts in the regions of seed production.

Many meadows and hayfields that had been sources of seed of local strains of grasses and legumes were put under the plow in the war years and planted to cereal and feed grains. The mechanization of many farming operations and economic problems changed many agricultural practices. Specialization in corn, soybeans, wheat, and other cash crops grew. Soil conservation practices caused some shifts in the use of land. Increasing numbers of livestock meant that many of the remaining meadows once used for both forage and seed were set aside for pasture and hay only. The demand for forage seeds of improved varieties has grown.

Imports of legume and grass seed before 1930 were relatively large. For several years we imported annually 40 million pounds of alfalfa and red clover seed. One year we imported 11 million pounds of alsike clover.

At one time, practically all the bahiagrass used in the South was imported. Our need now for this species is met almost entirely with domestic seed of improved varieties, which are superior in winter hardiness, persistence, and yield.

The total imports of forage seeds has dropped since 1930, primarily because of substantial increases in the domestic production of seed. Nevertheless, relatively large amounts of seed of sweetclover, crimson clover, birdsfoot trefoil, fescue, and orchardgrass were imported from overseas in 1960.

Most of the grasses and legumes available to farmers before the Second World War were the result of importations or seed increases of locally adapted types selected from introduced or native materials. Varieties were uncommon. The production of grassland seed was a minor enterprise on many farms.

Local customs dictated most of the production practices. The preferred or best adapted crop usually was grown, primarily for forage and soil conservation; when the weather was favorable, a seed crop was produced and harvested from a meadow or hayfield.

In those instances where varieties existed, little effort was made to maintain foundation planting stock and to minimize the chances of genetic contamination from cross-pollination with other varieties growing nearby. The characteristics of ecotypes and varieties therefore kept undergoing change from one generation to another. This gave rise to an increasing number of local strains, which were superior to imported seed.

Whereas seed once was a byproduct, a trend started about 1948 to plant exclusively for seed production. Such enterprises, to be most profitable, must take close account of the requirements as to climate, soil, and management of the variety.

Winter annuals usually do best where winters are relatively mild.

Some summer annuals are adapted to the South and others to northern latitudes. A generally favorable climate for most perennial species is characterized by winter conditions with near-freezing to freezing temperatures at night; a relatively rain-free growing season of 180 to 200 days; and clear, sunshiny days, with optimum daytime temperatures during set and development of seed ranging from about 75° F. for the cool-season grasses to approximately 95° for most perennial legumes.

Pollinating insects, such as bees, are essential for most legumes. These insects are relatively inactive on cloudy days and at temperatures below 70°.

The length of day required for flower initiation varies among and within species. The cool-season grasses and northern-adapted alfalfas and clovers usually blossom most profusely and according to schedule in the more northern latitudes under conditions of low night temperatures in spring and long, warm or hot days in summer.

As these grasses and legumes are moved south (into regions of shorter days) for production of seeds, many plants in normal populations of given varieties are retarded in both initiation and profuseness of flowering, particularly if night temperatures in spring are not low enough to fulfill the variety prechilling requirements for flower initiation. The unwanted genetic shifts that result cause changes in the characteristics of a variety.

GREAT PROGRESS has been made in breeding improved grasses and legumes since 1940.

The development of new varieties with disease resistance and tolerance to a greater range of temperatures and improved management technology have permitted the extension of some species of legumes and grasses into new regions and soils previously unsuited to grassland agriculture.

The growing interest in grassland farming meant that the demand for forage seeds could no longer be met by the older methods of producing seed from hayfields. The total yield of seed had to be increased and greater care had to be taken to guard against genetic shifts caused by effects of daylength, temperature effects, and outcrossing to other varieties and sorts.

Seed production had to advance from a minor to major farm enterprise.

The success of such an enterprise rests on proper management—row planting with proper isolation of fields, timely irrigation, forcing plant growth to flower when temperatures are favorable, adequate control of insects and weeds, satisfactory pollination, and timely harvest. Farmers who were willing to make seed production a primary business achieved success.

Production shifted to new sections. Bluegrass, alfalfa, and the bentgrasses are examples.

Kentucky and parts of adjoining States before 1920 produced more than half of the seed of Kentucky bluegrass harvested in the United States. Insect damage to old fields and declining soil fertility caused a shift to Missouri, Iowa, Nebraska, South Dakota, and North Dakota, which in 1960 produced more than 80 percent of our seed of Kentucky bluegrass.

Frequent summer rains in the Corn Belt and farther east, and sustained demand for hay were deterrents to the production of alfalfa seed. The primary sources of seed were the Great Plains and Intermountain regions, and until recently seed production was considered mostly a byproduct of hay production even in those sections. The production of alfalfa seed has mushroomed since 1945 in the West, where water for plant growth can be controlled by irrigation.

The bentgrasses once were important in pastures in the eastern New England States and later in turf plantings. For many years the seed was harvested in late summer from pastures that were grazed in spring and early summer. The seed, however, came to have so many weed seeds that bentgrass seed harvested from the established areas became unsuitable for lawn, golf courses, and other turf.

Similarly, bentgrass seed harvested from natural stands in the coastal sections of Oregon became unsatisfactory because of large numbers of seeds of other grasses and perennial weeds. Ergot and the nematodes, furthermore, caused sharp declines in yield and serious contamination of seed.

New seed fields therefore were established in inland irrigated valleys of Oregon. More than 90 percent of our bentgrass seed was grown in the non-coastal areas of Oregon in 1960.

The expansion of seed production in the West has doubled our output of alfalfa seed since 1945. Most of the expansion was in new irrigated seed-producing areas in the West, particularly in Washington and the Central Valley of California.

Just before the war, California, Oregon, and Washington produced less than 7 percent of our alfalfa seed; 15 years later, they produced well over 50 percent of the crop.

California alone produced more than 47 million pounds of certified Ranger alfalfa seed in 1955—about four-fifths of the annual production in the United States in 1930-1939.

Substantial amounts of seed of red clover are still harvested from hayfields and pastures in the eastern half of the country, but the dependable production of certified seed from new varieties now comes from the West.

Oregon and Idaho have produced a great deal of alsike clover since 1930. Total production of alsike seed declined by one-third since 1935, due largely to a drop in acreage and production in the Corn Belt, where the draining, liming, and fertilizing of wet and acid soils (which alsike clover likes) led farmers to shift to other, more productive forage crops.

Whiteclover seed is produced mainly in Wisconsin, Alabama, Mississippi, Louisiana, Idaho, and Oregon. The center of production of Ladino clover seed is California.

Oregon produced one-third of all crimson clover seed harvested in the United States in 1958-1959. The remaining two-thirds came from South Carolina, Georgia, Tennessee, Alabama, Mississippi, and Arkansas, where crimson clover is an important winter cover crop. We import sizable amounts of seed of crimson clover.

The production of lupine seed is confined to the Southeastern States, where the temperatures are favorable. The production of vetch seed is of economic importance in Arkansas, Oklahoma, Texas, California, Idaho, Oregon, and Washington. Austrian winter peas are produced in the Pacific Northwest. These winter annual legumes are grown for soil cover and green manure in the South Central and Southeastern States.

SOME EXPANSION of production of grass seed has occurred in regions outside the area where grass is used primarily for pasture, soil conservation, and turf, but the shift has been less pronounced.

Production of noncertified seed of orchardgrass has been centered in Kentucky, Virginia, and Missouri. Most of the certified seed of improved varieties of orchardgrass is grown in the West.

The western part of the Corn Belt continues to be the primary source of noncertified and certified bromegrass seed. A few other States have limited acreages of improved varieties of bromegrass for seed.

The production of timothy seed has declined since 1940. Most of it is harvested from pastures and meadows in the Corn Belt.

Nearly all redtop seed is harvested in Illinois and Missouri.

Production of red and chewings fescue is limited to Oregon, Washington, and Idaho. Tall fescue seed is produced primarily in Oregon, Kentucky, Tennessee, Missouri, South Carolina, Georgia, and Alabama.

The production and use of carpet-grass and dallisgrass seed in the Southeast has declined sharply since 1950 because of the vegetative plantings of more than 1 million acres of coastal bermudagrass and the growing popularity of improved varieties of bahiagrass, much of the seed of which we get from the Southern States.

Sudangrass, a summer annual forage grass, is grown in nearly all States. Its seed comes mainly from dryland or irrigated fields in the Southern Plains States westward to California.

Most pearl millet seed is produced under irrigation in New Mexico, Texas, and Arizona. It is used mainly in the Southeastern States.

The production of ryegrass seed is a highly specialized enterprise in Oregon.

Plantings of Merion bluegrass for seed are mostly in Oregon, Idaho, Washington, and California.

Crested wheatgrass and closely related species are best adapted to the northern Great Plains and Intermountain States to the west for the production of seed.

THE NATIVE GRASSES are well adapted to the Great Plains.

Until about 1950, most of the seed was harvested from wild stands, which usually included mixtures of species. Increasing acreages have been devoted since then to growing certified seed of more than 15 new varieties of 7 species. They are grown primarily in Nebraska, Kansas, Missouri, Oklahoma, Texas, Colorado, New Mexico, and California.

The primary values of grasses and legumes are for pasture and hay, soil conservation, and turf. Management for those uses usually precludes seed production. Management for both forage and seed production results in a costly and hazardous farm operation. Climatic conditions best suited for forage production and cropping practices conducive to good soil conservation often are unfavorable for the production of seeds.

Production of seed therefore has become specialized and has moved westward to places where the climate is more favorable for seed set, curing, and harvest.

Unlike some other crops, the seed of many improved grass and legume varieties is produced far from the areas of use. Along with this development, increasing numbers of grassland farmers in the Central States and East have found it good business to shift from byproduct seed production to more profitable crops and cropping practices.

These developments mean that the specialized grower will have to continue to be aware of the needs of those who buy and plant his seeds.

He needs to keep himself informed about changes in agricultural programs, new varieties, their adaptation and use, demands, seed-yielding capacity, safeguards in seed production, and the replacement of old varieties by the new.

Alfred Stefferud

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