CORN OB MAIZE 71 



from 2 to 4 weeks for completion, depending on condi- 

 tions for growth. 



57. Grading seed corn. Many growers think it is 

 necessary to plant corn from the butts and tips to insure 

 well-filled butts and tips in the progeny. Reports of 

 eight experiment stations of tests running from 1 to 9 

 years in which the seed from the butts, tips, and mid- 

 dles of the ear was compared, showed that there has been 

 practically no difference in yield. In order to get a 

 uniform drop from the planter, it is a good plan to shell 

 off the butts and tips from the seed ear. To still further 

 increase the efficiency of the planter, it is well to select 

 ears that are uniform in the size and shape of the kernel. 

 A seed corn grader made up of three sieves with openings 

 of different sizes may be used to remove the large and 

 small kernels. Iowa Station reports that a planter using 

 seed graded in this way gave 95 per cent of a perfect drop. 



58. Time of planting. Corn may be planted in the 

 spring as soon as the danger from frost is over, and the 

 soil is warm enough for the seed to germinate. Planting at 

 this time would be regarded as early, while if it is delayed 

 three or four weeks from this time it would then be con- 

 sidered late planting. The date at which the soil is at 

 the proper temperature and the danger of frost is over 

 will vary in a given locality with the season, and in different 

 sections with the latitude. Early planting usually gives 

 the best yield of mature corn. Corn planted late quite 

 frequently has from 25 per cent to 35 per cent of moisture 

 at harvest time, and in this condition is likely to spoil in 

 the crib. Early planting is often impossible because of the 

 lack of proper drainage which prevents early preparation 

 of the soil. In many cases the increase in yield of mature 

 corn will in a few years pay for the draining. 



