Clipping is not generally recommended in the West, although clipping may help control weeds, diseases, and insect pests. If clipping is necessary, it should be done at about the time of the first bloom. The first crop is always clipped or grazed in the Midwest. The highest yields were obtained in Kentucky when the first crop was cut about June 1.

Because the red clover flower is practically self-sterile, cross-pollination is essential for a commercial seed crop. Two hives of domestic bees per acre usually are enough in the West. Better yields are obtained with three to four colonies per acre in the Midwest. They should be placed in the field when the plants begin to bloom.

Fertilizers often increase yields. Phosphorus, potash, and sulfur should be applied if they are deficient in the soil.

Two insects that must be controlled if seed of red clover is to be produced satisfactorily are the clover seed midge (Dasyneura leguminicola) and the clover seed chalcid.

Other pests that may cause damage include lygus bugs, grasshoppers, armyworms (Prodenia), spider mites, and clover root borer (Hylastinus obscurus).

Land relatively free of weeds should be used for producing seed of red clover. Cultivation generally is the most economical way to kill weeds where it is possible, as in row plantings. In excessively weedy, close-drilled or broadcast stands, it may be necessary to use herbicides or pull the weeds by hand. If weedy winter annual grasses are a problem, pelleted or granulated IPC isopropyl N-phenyl-carbamate is effective. In California, the IPC material should be applied on wet soil in December and January when the soil is cold.

Harvesting methods are similar to those for alfalfa, except that red clover is not usually combined standing and is harder to thresh.

ALSIKE CLOVER is used in hay and pasture mixtures in the eastern half of the United States and in the higher elevations of the Western States. It is especially useful in wet meadows and acid soils where other clovers do not thrive.

Like red clover, alsike is a perennial that generally behaves as a biennial.

The seedbed for alsike clover should be firm, uniform, and well drained. Fall and spring plantings are common in the Klamath Basin of Oregon. It usually is seeded in early spring in the colder regions. It may be broadcast, drill seeded alone, or drill seeded into established stands of small grain in early spring or grain stubble in the fall.

Broadcast plantings take 8 to 12 pounds of seed; 6 to 8 pounds is adequate when it is drill seeded. Alsike generally is grown in solid stands.

Under irrigation, the management of water is important. Alsike seedlings are slow to establish roots and require an abundance of water. The soil should not be allowed to dry to a depth greater than 1 to 2 inches until 2 or 3 weeks before harvest.

Alsike clover will thrive only if proper bacteria are present. Its seed should be inoculated when it is planted for the first time in a field.

Alsike plantings usually respond to phosphorus or sulfur or both in the Klamath Basin. Applications of 300 to 400 pounds of single or ordinary superphosphate at planting time may increase yields of seed.

The best yields are produced on early growth. Cutting back to condition stands for seed production therefore is poor management.

Pollination requirements are similar to those of Ladino whiteclover.

The major pests of alsike are the clover seed weevil (Miccotrogus picirostris), the clover root curculio (Sitona hispidula), and several species of lygus bugs. The pea aphid and clover aphid (Anuraphis bakeri) may also require control.

Rodents, field mice, and gophers often are problems in seed fields. Excellent control of field mice has been obtained by using toxaphene, which is applied in water at the time the field mice are feeding on the plants above the ground.

Harvesting is done much as with alfalfa, but alsike seed is small and shatters if it is not handled carefully.

LADINO CLOVER will do best on heavier clay or loam soils. It does well on shallow soils underlain by a tight clay layer or hardpan, even if the restricting layer is within 12 to 18 inches of the soil surface. Ladino clover does not thrive on saline soil. Seed production is seldom successful on deep, open, friable, fertile soils, because plants fail to produce an abundance of seed heads unless they are irrigated frequently.

Ladino clover grown for seed requires irrigation every 7 to 12 days during the 60 to 80 days required to set a seed crop. Careful preparation of the land to provide economical and uniform application of water and to facilitate other cultural operations is essential. The border system of land preparation is in general use.

A fine, firm seedbed is recommended. The surface should be firmed by cultipacking, rain, or irrigating before seeding.

Seeding can be done in September or November or in February. Spring seeding is preferred if fields are foul with winter weeds.

The rate of seeding is 4 to 6 pounds per acre when broadcast or drill planted. The seed should be covered to a depth of one-fourth inch or less.

Inoculation of Ladino seed is recommended, particularly on new lands not previously in clover.

The production of seed in stands or pasture plantings will benefit from liberal applications of phosphorus and sulfur if the soil is low or deficient in those elements. New seedings of Ladino in California respond to nitrogen, phosphorus, and sulfur. Many growers broadcast 200 pounds per acre of 16-20-0 and 100 pounds of agricultural sulfur before seeding new stands.

Grazing or mowing seed fields in late April or early May helps control weeds. On stands of seedlings, dinitro selective sprays are effective against young broad-leaved weeds. The dinitro selective sprays should be used with extreme caution in seedling Ladino if the air temperature is above 75 F.

In established fields, when properly used, 2,4-D (2,4-dichlorophenoxyacetic acid) has proved effective against such troublesome weeds as dock, buckhorn, plantain, chicory, and dodder.

When 2,4-D is used, time of application, type of material to be used, and the rate of the application are important.

In irrigated areas, fields sprayed with 2,4-D should be kept well watered for 3 to 4 weeks following treatment.

Weedy grasses, particularly winter annual species, can usually be controlled by applying granulated or pelleted IPC. The IPC material should be applied when the ground is wet and cold.

Because daylength affects flowering of all whiteclover and may influence setting of seed, the time of cutting back or grazing preparatory to seed production is important.

The recommended time to condition the stand for Ladino seed production in California is May 5 to 20. The regrowth of plants to full bloom requires 25 to 30 days. Therefore seed setting would start about June 30 to July 20 and continue to August 20 or September 10. Harvest is 15 to 20 days later.

Ladino clover plants are extremely variable. Locality, time of seed setting, and plant differences may affect the genetic composition of strains or varieties that are grown under different environments.

E. H. Stanford and his coworkers at the University of California studied the effects of harvest dates and location on the genetic composition of the Syn. 1 generation the first generation produced by the interpollination of a group of plants in isolation of Pilgrim Ladino clover.

They concluded: "Parental clones of Pilgrim Ladino clover differ in their seed-producing ability. The relative amounts of seed produced by individual clones varies with harvest dates and areas of production. Pollen contribution of individual clones also differs. If genetically uniform lots of breeder seed are to be produced, they must be produced under similar environmental conditions."

Daylength also governs the area where seed of Ladino clover can be grown. South of about 32 north latitude the daylength is too short to promote profuse formation of flowers.

Investigations in California indicated that time of harvest in relation to cutting back is important. Tests showed these yields: 180 pounds per acre, when harvested in 52 days after cutting back; 280, in 66 days; 298, in 75 days; 407, in 96 days; 380, in 110 days; 298, in 120 days; and 280 pounds in 130 days.

The loss of seed, as indicated by harvests after 110 days of production, were due to deterioration of pedicels, heads, and pods, which led to shattering of seed, dropping of heads and pods, and germination of seed after irrigation.

The flowers must be cross-pollinated. Wind and rain are not effective carriers of pollen. Bumble bees and many other wild bees are useful and effective, but usually there are so few of them that one cannot rely on them for effective pollination. Honey bees therefore generally are used. An average of 1 or 2 strong colonies to the acre is enough for complete pollination.

Lygus bugs, grasshoppers, cutworms (Chorizogrotis auxiliaris), armyworms, and spider mites (red spider) must be controlled to produce Ladino seed.

The crop is ready to cut when about 90 to 95 percent of the seed heads are brown and the flower stems have started to dry (usually 90 to 110 days after cutting back). The crop is usually harvested by one of three methods direct combining, following spray curing; combining from the windrows; and by stationary threshers.

To cure, Ladino is cut as close to the ground as possible. The mower is equipped with a curler to windrow, or a side-delivery rake is used for windrowing following mowing. Sometimes it is dried in the swath and windrowed at night before threshing. Desiccation or chemical curing also is used. Curing usually takes 4 or 5 days.

THE SEED HABITS of birdsfoot trefoil are such that sometimes much seed is lost.

The seed ripens unevenly. The ripe pods pop open, and seed shattering may lead to a complete loss of the crop.

Localities that have relatively cool Summer temperatures and moderately high daytime humidity (40 to 60 percent) are best suited to seed production. Seed is produced in Oregon, California, North Dakota, Minnesota, Iowa, Vermont, and New York.