WHITE CLOVER 3 



countries and from the British Isles. No definite information is 

 available on the uses of white clover seed in this country, but it is 

 believed that approximately 95 to 98 percent is used in lawn-seed 

 mixtures. While the amount of white clover seed produced in the 

 United States fluctuates widely from year to year, the three principal 

 seed-producing regions and their relative importance in the United 

 States are (1) Louisiana, (2) Idaho, Oregon, and Washington, and 

 (3) the northern Corn Belt States, principally Wisconsin. For- 

 merly, most of the seed was produced in the northern Corn Belt 

 States. 



Pollination 



White clover is practically self -sterile ; that is, the florets have to 

 be cross-pollinated before seed will form. This means that pollen 

 must be transferred from plant to plant rather than from one floret to 

 another on the same head or the same plant. The florets produce 

 an abundance of easily accessible nectar and, therefore, are visited 

 by all kinds of bees, which in their quest of nectar cross-pollinate the 

 flowers, thus bringing about continuous variation in the progeny. 

 Under different environmental conditions various types and forms 

 of white clover have developed and survived, giving this plant a 

 wide range of adaptation. 



Culture 



White clover, like all the other clovers, thrives best under cool, 

 moist growing conditions, in soils abundantly supplied with lime, 

 phosphate, and potash, but it is more tolerant of adverse conditions 

 than any of the other important clovers. Clay and loam soils, pro- 

 vided they remain sufficiently moist to keep the plants alive, seem 

 better suited to white clover than sandy soils, probably because of the 

 droughty nature and lower mineral content of the sandy soils. White 

 clover is not regular in its persistency of growth. It occurs abun- 

 dantly in some years, but diminishes in others to such an extent that 

 it almost disappears. The reason for this spasmodic behavior is not 

 clear. Experiments have shown that the application of from 200 to 

 400 pounds per acre of phosphate fertilizers is beneficial to the growth 

 of this plant, and while it will grow on acid soil its growth is never 

 so thrifty as when available lime is present. Occasionally, clover 

 leaves become spotted with irregular light -brown areas, even in the 

 absence of disease-producing organisms, a condition which has been 

 remedied by the application of 75 to 150 pounds of potash fertilizer 

 per acre. 



On most soil types, after stands are established, an application of 

 phosphate at frequent intervals has been shown to be beneficial to the 

 growth of white clover. The top dressing of white clover with lime- 

 stone and potash has in many places given profitable returns. Re- 

 peated applications of fertilizers containing a high percentage of 

 nitrogen have generally been unfavorable to the growth of white 

 clover. 



As white clover usually grows in association with grass, climatic 

 conditions and cultural treatments affecting the grass may indirectly 

 affect the clover. In England the management of pastures which 

 are composed in part of white clover has a pronounced influence on 



