WATER-STRESS BEHAVIOR OF PIMA COTTON. 
17 
plat 4 at that time was only 17.5 inches, as compared with 25.7 inches 
as the average height of the plants on plat 1 (fig. 1, />, and PI. I), 
it could hardly be stated that the former plants were stunted. At 
that time they were growing in a satisfactory manner, and appar- 
ently the supply of soil moisture was ample for their need. 
J 5 15 21 30, <5 13 20 27, g_jfO_J6J&J£ J 
JULY 
S9UGU&T 
SEPTEMBER 
Fig. 3. — Average percentage of available moisture per week in 4 feet of soil and the 
weekly flowering curves of four plats. 
Figure 3, B shows that the flow r ering rate of the plants in plat 1, 
which were growing at a more rapid rate than those of plat 3 (fig. 
1, B) during July was greater than plat 3. but did not continue at 
the same relative rate later in the season. During the w T eek August 
20 to 27. the rate of flower production in plat 3 became equal to that 
