ILLUSTRATIONS 



PLATES 

 Relative Water REQxnREMENT op Plants 



Pase. 



Plate I. Fig. i. — General view of the plant inclosure used at Akron, Colo., 

 showing the pipe framework covered with a hail screen, with the board 

 base surmounted by a single width of cheesecloth to protect the plants 

 against high winds. Fig. 2. — General view inside tlie inclosure, showing 

 the arrangement of pots and general conditions of growth. Com and 

 sorghums are shown in the foreground, small grain in the background. 

 Fig. 3. — General view of the inclosure photographed shortly after the grain 

 in some of the pots had been harvested 64 



Plate II. Fig. i. — Pot planted with sugar beets, showing the wax seal around 

 the plants and also the sealed holes where stand was not perfect. Fig. 2. — 

 Weighing pots, showing spring balance, weighing support, and general 

 procedure. Two men operate the weighing support, one of whom lifts the 

 pot by means of a windlass, while a third reads the balance and records the 

 weight. By this method weighings can be made at the rate of two per 

 minute. Fig. 3. — Gnndelia squarrosa (gumweed) and Artemisia frigida 

 (mountain sage), illustrating the growth of native plants used in the water- 

 requirement meastu'ements 64 



Plate III. Fig. i. — Kubanka wheat, grown May 9 to September 3 , 1912. Fig. 

 2. — White Hull-less barley, grown May 16 to August 12, 1912. Fig. 3. — 

 Kubanka wheat. Set grown outside of shelter, May 9 to August 31, 1912. 

 Fig. 4. — Emmer, grown May n to August 12, 1912. Fig. 5. — Swedish Select 

 oats, grown May 17 to August 23, 1912. Fig. 6. — Kharkov wheat, grown 

 April 27 to August 28, 1912 64 



Plate IV. Fig. i. — Northwestern Dent com, grown JunS 9 to September 16, 



1912. Fig. 2. — Hopi com, grown June 12 to September 26, 1912. Fig. 3. — 

 White durra, grown June g to September 26, 1912. Fig. 4. — Red Amber 

 sorghum, grown June 29 to September 27, 1912. Fig. 5. — Minnesota Amber 

 sorghum, grown June 9 to September 26, 1912 64 



Plate V. Fig. i. — Sudan grass. First crop, grown May 28 to July 26, 1912. 

 Fig. 2. — Voronezh proso, grown June 5 to August 20, 1912. Fig. 3. — Kiu-sk 

 millet, grown June 9 to August 20, 1912. Fig. 4. — Select Grimm alfalfa, 

 grown in the open. May 24 to July 27, 1912. Fig. 5. — Select Grimm alfalfa, 

 grown in the shelter. May 24 to July 26, 1912 64 



Plate VI. Fig. 1. — Cowpea, grown June 17 to August 26, 1913. Fig. 2. — Hairy 

 vetch, grown May 29 to July 18, 1913. Fig. 3. — Soy bean, grown June i to 

 August 26, 1913. Fig. 4. — Cantaloupe, grown June 14 to September 13, 



1913. Fig. 5. — Indian Flint com, grown June 7 to August 27, 1913. Fig. 



6. — McCormick potato, grown June 5 to October 4, 1913 64 



Plate VII. Fig. i. — Triumph cotton in .shelter, grov^-n May 29 to September 

 16, 1913. Fig. 2. — Bocbera papposa, grown July 25 to vScptember 17, 1913. 

 Fig. 3. — Rice in shelter, grown June 12 to September 16, 1913. Fig. 4. — 

 General view of the shelter, showing emmer at the left and White Hull-less 

 barley at the right. Fig. 5. — General view in the shelter, showing com in 

 the foreground 64 



