36 FIELD CROP PRODUCTION 



incapable of fertilization, and likewise are heavy rains 

 unfavorable, since the water washes the pollen to the 

 ground. The corn plant is cross-pollinated or wind- 

 pollinated. Self-pollination has been rendered difficult by 

 the position of the male and female flowers, the anthers 

 being so placed that a light breeze is necessary to spill the 

 pollen, which will insure its being carried away to other corn 

 plants. Another provision made by nature to prevent 

 self-pollination is that the silk almost always matures 

 after the pollen of that plant is shed. A single corn plant 

 out of reach of pollen from other corn plants usually has 

 either a few scattered grains on the ear, or no grains are 

 produced at all. 



31. The ear. — The ear is carried on a short shank or 

 branch growing from a, node between the leaf sheath and 

 the culm. The shank is made up of several short inter- 

 nodes, from each of which grows a husk, and these, overlap- 

 ping, form the covering of the ear. When the shank is 

 short, the ear stands upright ; but if it is long, the ear tips 

 over and at maturity points do^vnward. In fertile soil or 

 in favorable growing seasons, ear shoots may start from 

 several nodes, but usually only one or two develop. The 

 top one develops first, and if it is removed the one below it 

 grows to maturity. Some varieties, especially those grown 

 in the southern part of the United States, often produce 

 two or more ears per stalk. Most of the varieties grown 

 in the Northern States produce but one ear, but in thinly 

 planted fields or in favorable seasons, two ears per stalk 

 are quite commonly found. There is great variation in 

 the size of the ears and in the number of rows of grain. 

 The ears vary in length, from one inch in certain varieties 

 of pop corn, to as much as 16 inches in some of the larger 

 varieties of dent corn. The number of rows of grain varies 



