Yields of Maize ivitli Irrigation 191 



-varieties of corn, but also where the corn was irrigated and. where 

 it was not irrigated. It will be seen, further, that the smallest 

 yield of dry matter per acre was produced where the smallest 

 amount of seed was used, namely, where 1 stalk grew every 15 

 inches ; but one-third the number of plants produced about three- 

 fourths as much dry matter per acre as did the larger number of 

 plants. 



It must be understood, however, that so far as mere water 

 is concerned, the thinnest planting had decidedly the advantage, 

 as no effort was made, even on the ground irrigated, to make 

 the water applied proportional to the number of plants and, there- 

 fore, to the evaporating surface. Whether making the amount 

 of water proportional to the number of plants would have materi- 

 ally increased the yields of the thicker seeding, is a problem 

 which awaits demonstration. Indeed, we do not, as yet, know 

 that the thinnest seeding had all of the water which could be used 

 to advantage, even where irrigation was practiced. But the fact 

 that the smaller variety of maize, Pride of the North, the one 

 which produced no suckers, and, therefore, the one which more 

 nearly represented 1 stalk every 15 inches, only gave an increase 

 of 408 pounds of dry matter per acre for the 7.642 inches of water 

 added by irrigation to the rainfall of 10.66 inches, appears to show 

 that this corn found in the 10.66 inches of rain nearly all the 

 water it could use to advantage. This view is strengthened, 

 also, by the fact that the theoretical yield of dry matter per 

 acre for the maize, computed from the data in the table on 

 page 187, is 8,848 pounds, only 312 pounds more than was 

 observed. 



Looking at the yield of kiln -dried shelled corn per acre, it 

 will be seen that here a somewhat different relation holds, the 

 largest crop with the white dent variety being secured from 2 

 stalks in a hill every 15 inches ; but with the smaller variety of 

 Pride of the North the largest yield of shelled corn coincided 

 with the 3 stalks in a hill where irrigation was practiced ; but 

 where the natural rainfall alone produced the crop, the largest 

 yield was associated with the thinnest seeding, or 1 stalk every 

 15 inches in the row. It is a noteworthy fact, too, that -the 7 ..642 



