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, B, 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 8 15 21 30, <S /3 20 27, ,3 /O /6 23 

 JULY S?L/GU&T <S£PTEMB£ft 



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 flowering 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 week August 

 20 to 27, the rate of flower production in plat 3 became equal to that 



