PREPARATION- AND PLANTING 



173 



finding an average range of about six weeks for corn 

 planting. The very earliest and the very latest plantings 

 are usually not so successful as those about midseason. 

 For example, the Illinois station in 1890 made plantings 

 from April 28 to June 9. The average yield of the corn 



Fig. 49. — Special attachments for corn planter shoes. 



planted in May was 73 bushels per acre, while the average 

 yield of the three remaining plantings, one in April and 

 two in June, was 63 bushels per acre. 



Manjr experiments at other stations bear out the state- 

 ment that there is a period of about three weeks for corn 

 planting with equal chance of success, though there are 

 occasional seasons when the very early or very late plant- 

 ings are best. The optimum season is shorter in the North 

 and longer in the South. 



TABLE XXXVII 

 Time of planting Corn in Certain Regions ' 



U. S. Dept. Agr. Yearbook, 1910, p. 491. 



