INHERITANCE— IMPRO VEMENT B V BREEDING 129 



average yield, which is estimated at between 4 and 5 muids CHAP. 

 (800 to 1,000 lbs., or 14-28 to 17-9 bushels). v - 



This is astonishingly low as compared with the 2 2i to 24 

 muids obtained (without manure) in the United States. Even 

 assuming that the soils of the South African Maize-belt are 

 perhaps not as rich as those of the United States Corn-belt, 

 there is still much too great a discrepancy between the average 

 yields of the two areas ; it has been clearly demonstrated on 

 the Government Experiment Farms, and on many private 

 farms as well, that average yields of 10 and 12 muids (354 

 to 42-i bushels) per acre over hundreds of acres can be secured 

 without undue expense. 



But good as the American yields are as compared with 

 those at present obtained in South Africa, American breeders 

 find it is possible still greatly to improve them. Mr. C. P. 

 Hartley, corn expert of the United States Department of 

 Agriculture, writes {Hartley, 3) : — 



" It is possible within a few years to double the average 

 production of maize per acre in the United States, and to 

 accomplish it without any increase in work or expense. It is 

 not to be understood from this statement that it is desirable 

 to double the present maize crop, but that it is desirable to 

 produce the same yield on a smaller number of acres and with 

 less labour. If 60 bushels (a bushel of maize on the ear is 

 calculated at 70 lbs. weight) are raised on 1 acre instead 

 of on 2 acres, the labour of ploughing, harrowing, planting, 

 cultivating, and harvesting is greatly reduced. The demand 

 controls the quantity that should be grown. To meet demands 

 the producers of the United States have, during the ten years 

 previous to 1914, averaged in round numbers 2,000,000,000 

 bushels of maize yearly. In producing this amount a little 

 more than 82,000,000 acres have yearly been devoted to maize- 

 growing. The average production . . . for the past ten years 

 has been less than 25 bushels per acre, but from the best 

 estimates that have been made the conclusion is unavoidable 

 that half of those who grow maize harvest less than 25 bushels 

 per acre. Twice this quantity is a fair crop, three times 25 

 bushels is a good crop, and four times 2j bushels per acre are 

 frequently produced. 



" The lines of improvement that will most easily and quickly 

 double the present production per acre are as follows : (1) 



9 



