Oct. 15, 1914 



Water Requirement of Plants 



17 



Table XII. — Water requirement of cotton at Akron, Colo., in igi3 and igij 



The same variety was also included in the 1913 measurements. (PI. 

 VII, fig. I.) The planting was made earlier, and a much larger growth 

 was obtained. The water requirement was 657^11, or about one-third 

 higher than in 191 2. In this connection it should be stated that at 

 Akron cotton is far north of its natural range, which may have increased 

 its relative water requirement. 



CORN AND TEOSINTE 



Six varieties of com (Zea mays) were tested at Akron in 191 2 (PI. 

 VII, fig. 5). Three of these varieties, Northwestern Dent (PI. IV, 

 fig. i), Iowa Silvermine, and Esperanza, had also been used in the 191 1 

 experiments. The three new varieties were furnished by Mr. G. N. 

 Collins, of the Bureau of Plant Industry, and represent widely different 

 strains. The Hopi variety (PI. IV, fig. 2) is grown by the Hopi 

 Indians in northwestern New Mexico (Collins, 1914); China White is a 

 variety from near Shanghai, China; while Laguna was originally from 

 the State of Chihuahua, Mexico. The water requirement of each variety 

 tested in 191 2, based on the production of dry matter, is as follows: 



Variety of corn Water requirement 



Esperanza ^39:^^5 



Northwestern Dent 28o± 10 



Hopi 285±7 



Laguna 295 ±6 



Iowa Silvermine 302 ±7 



China White 3iS±7 



The Esperanza, as in 191 1, leads all the varieties, so far as efficiency 

 in the production of dry matter is concerned, and ranks with the sor- 

 60300°— 14 2 



