156 GRASSES OF IOWA. 



the sea, it is therefore a highland plant. Its original home was 

 south of the 22"^ north latitude. 



In regard to the climate Brewer* states: "That the bulk of 

 corn is grown not as is generally supposed, in the warmer parts 

 of the United States, but in the states Illinois, Iowa, Missouri 

 and Indiana 40.8 per cent of the entire crop grows where the 

 mean annual temperature is between 45° and 60° F. Below an 

 annual temperature of 45° F. the product falls off very rapidly, 

 while above 50" F. it falls off very slowly. The distribution 

 of the crop depends on certain climatic conditions. Ihe mean 

 annual temperature is of les > importance, and it is very impor- 

 tant that ihe rain fall should be evenly distributed. "The 

 table of the distribution of the crop according to elevation 

 shows that over 50 per cent is grown at an elevation of between 

 500 and 1.500 feet, only 4.4 per ceat above that, and only about 

 an eighth of the crop is grown nearer the sea level than 500 

 feet." 



Corn needs hot weather, plenty of suQshine and a sufficient 

 amount of rainfall. In 1894 the average yield for Iowa was 

 twelve bushels per acre, a little over one-third of an average 

 crop. Acreage planted 6, 738, 970; total yield 80, 867, 640 bushels. 

 About 60 per cent was cut for fodder. It is interesting to note 

 the fluctuation in the crop reports for that year. The figures 

 were in Juae, 101 per cent; July, 107 per cent; August, 40 per 

 cent, and September, 36 per cent. 



Mr. C. F. Spring, under the writer's direction, has made an 

 estimate of the number of bushels per acre in the north half of 

 the state, and the south half. Tne average for the north half 

 of the state for the year was thirty-six bushels per acre; for the 

 soutti half, thirty-eight. 



Every portion of the state of Iowa is adapted to the growing 

 of corn, and from a climatic standpoint corn is one of the most 

 interesting of cultivated plants. It is woaderfully flexible in 

 its nature, and this flexibility makes it possible to cultivate it 

 over a wide range of latitude. Simmondsf says: "Its flexibil- 

 ity of organization makes it very easy of aiaptatioa to cli- 

 mate and soil. " It is now cultivated on the western continent 

 from Patagonia to Canada, an extent of territory north and south 

 of over 7,000 miles. The many varieties that have been pro- 

 duced un^er these very different conditions show great vari- 



•Cereal production. U. S. Tenth Census Rep 3:100. 

 tTropIcal Agrl. 296. 



