28 THE CEREALS IN AMERICA 



of grain. It would not appear that there is any necessary re 

 lation between the length of straw and the yield of grain, although 

 all other things equal, the longer the culm, the greater the yield 

 of grain. The club varieties of wheat grow about two feet high, 

 while common wheat varieties grow to a height of from three to 

 five feet ; probably the average height is four feet. 



The length of the culm has an important influence upon the 

 liability to lodge, and also influences the ease of harvesting. It 

 seems probable that the yield of straw may affect the loss in soil 

 fertility, especially if the straw is not returned to the soil. On 

 land of good average fertility the Ohio Station produced ninety- 

 five pounds of straw for each bushel of wheat during a period of 

 ten years' continuous culture without fertilizers ; 115 pounds per 

 bushel where a complete commercial fertilizer was used, and 1 1 1 

 pounds per bushel where farm yard manure was used annually.^ 



During the early growth of wheat the nodes are very close 

 together and consequently the plant consists principally of leaves. 

 This condition obtains until the wheat begins to shoot, which 

 consists of the lengthening of the internodes and the pushing up 

 of the spike. The leaves which were formerly bunched together 

 within a foot of the surface of the ground are now scattered 

 along the culm, and in field conditions are comparatively 

 scanty, and apparently inactive, except near the top of the culm, 

 even at the time of blossoming. As the weight of the starch, as 

 well as other material laid up in the seed subsequent to this 

 time, is large, and as no starch is found laid up in the leaves 

 prior to this time, as in some other plants, the question has been 

 raised as to the ability of the active leaves to elaborate so much 

 starch in so short a time. In fact, during the latter part of the 

 ripening period only the glumes and the upper part of the stem 

 remain green. Investigations indicate that the glumes do not 

 have the capacity to form carbohydrates from the air, while the 

 upper part of the stem has such power.^ 



1 Ohio Bui. no, p. 47. 



8 Ann. Agron. 28 (1902'), No. 10, pp. 522-527. (E. S. R., Vol. XIV, p. 634.) 



