Crimson clover is a prolific seed-producing plant and yields of 5 to 10 bushels per acre are common, depending upon the thickness of the stand, the amount of growth that is produced, and the care exercised in harvesting the seed. The florets are self-fertile, but bees are effective in tripping and transferring the pollen, with a consequent increase in the number of seed per head. The placing of colonies of honeybees adjacent to blooming fields will effectively increase pollination. More seed is usually produced on soils of medium fertility than on rich soils, since fertile soils seem to stimulate the growth of stems and leaves at the expense of flower-head development.

Large yields and ease of harvesting crimson clover seed are the principal reasons why crimson clover is such an ideal legume crop. Farmers may save seed with very little expense other than their own labor. When the seed heads are mature they readily shatter and are easily harvested either by hand stripping or by using horse-drawn homemade strippers. One bushel of unhulled seed contains about 2 pounds of hulled seed, and although bulky in nature, it can be easily stored on the farm until fall.

When the seed is mature the crop is cut with a mower, which may be equipped with a bunching or windrowing attachment (fig. 6) or it may be harvested with a combine. During wet seasons difficulties in combining the seed from standing plants may be experienced. Under such conditions the plants may be cut and windrowed and then threshed by the combine from the windrow. As crimson clover shatters easily when ripe, cutting with the mower when the heads are damp with dew or rain is recommended. If allowed to stand too long after it is ripe a beating rain will shatter much of the seed. After a few days of curing, the seed is hulled with an ordinary clover huller or a grain separator equipped with hulling attachments. The less the clover is handled, the less seed will be lost by shattering.

Troublesome weeds are encountered in growing crimson clover seed; field peppergrass (Lepidium campestre) and wintercress (Barbarea praecox) are probably the worst, as their separation from the clover seed is difficult. Little barley (Hordeum pusillum) is objectionable in unhulled seed, and the use of unhulled seed will naturally increase the prevalence of this weed.

U. S. GOVERNMENT PRINTING OFFICE: 1938

For sale by the Superintendent of Documents, Washington, D. C. — Price 5 cents