CLIMATE FOR MAIZE 207 



280. Need of Water. — At the Illinois Station, from eighteen 

 varieties of maize on eighteen tenth-acre plats, the author 

 obtained thirty-two bushels of dry shelled grain per acre. The 

 next season, with the same varieties on the same plats, with 

 cultural methods as nearly identical as possible, and without the 

 addition of any fertilizer, ninety-four bushels per acre were 

 obtained. During the first season, the rainfall for the five grow- 

 ing months (^May to Septembex^) was thirteen inches ; during the 

 second, twenty-two and a half inches. During the same period 

 the average temperature for the first season was 73° F. ; the 

 second, 69° F. (276) 



The amount of water evaporated from the maize plant and 

 the surrounding soil has been determined by King ^ to be in 

 Wisconsin 270 pounds for each pound of dry matter grown, 

 equivalent to a rainfall of 2.4 inches for each ton. This is only 

 about half that required by oats and clover. Maize is, however, 

 very greatly influenced by the water supply in July and August, 

 since during that time the period of growth is very rapid. The 

 author has determined the growth of maize in one week in July 

 in Illinois to be equal to 1,300 pounds of dry matter per acre, 

 which would require, according to the experiments of King, 

 1.5 inches of rainfall. (350) At such times, unless the ph3'si- 

 cal conditions of the soil are the best, the plant is apt to suffer 

 from a lack of water, or, in other words, from drouth. 



281. Influence of Rainfall. — Everything points to the impor- 

 tance of water in the successful culture of maize. Beale has 



1 King: Physics of Agriculture, p. 139. 



