506 PLANT BREEDING 



greatest producing state, Illinois, the average crop is hardly 

 thirty bushels per acre. The use of choice seed has been found 

 to increase the production from 10 to 20 per cent, and it is a 

 moderate estimate which assumes that the universal use of 

 improved seed would add 10 per cent to the total corn crop of 

 the country. This would add over $100,000,000 to the annual 

 receipts of our corn growers. 



2. Improved quality. In every 100 pounds of ordinary shelled 

 corn there are, in round numbers, about 



8 Ib. embryo (of which 3 Ib. are oil) ; 



13 Ib. gluten, or proteids of the endosperm ; 



64 Ib. starch. 



There is a demand for a limited amount of corn with a high 

 per cent of oil as a source of corn oil. At the Illinois Agricul- 

 tural Experiment Station the attempt has been made to breed 

 varieties of corn with high and with low percentages of oil. 

 One variety was secured with nearly 7 per cent and another 

 with less than 2 per cent. 



In the same way, that is by means of continued selection, 

 carried through many generations, varieties with much or little 

 starch can be obtained. 



3. Early maturing. Corn was originally a tropical or sub- 

 tropical plant, requiring a long growing season. Quickly matur- 

 ing varieties had, however, been secured by the native races 

 even at the time of the discovery of America by Columbus. At 

 present there are varieties ranging all the way from the eighteen- 

 foot kinds that require a growing period of six months, to the 

 two- or three-foot kinds that mature in ninety days or less. 



The most important problem that presents itself to the plant 

 breeder in this connection is that of increasing the yield per 

 acre for each of the agricultural regions where corn is produced, 

 whether in the North, where short-stalked, early-maturing kinds 

 are needed ; in the great corn belt ; or in the South, East, or 

 West, where varieties are needed which are bred to make the 



