May 3 i # 1924 Comparison of Pima Cotton with Upland Varieties 
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Figures 1 and 2 show in graphic form the growth rate data contained in 
Tables III and IV, which makes a direct comparison of the height and length of 
the growing period of the different varieties easier. 
DIFFERENCES IN FLOWER PRODUCTION 
The number of flowers produced each day in the 25-plant sections, the number 
of bolls that were shed, and the number of bolls that were retained and developed 
in the seasons of 1922 and 1923, are given in Tables V and VI. The Upland 
varieties began to flower about a week before Pima with the exception of the 
replanted Lone Star in 1922. Also the Upland varieties usually produce a 
larger number of flowers than does Pima, but this advantage is reduced by 
much greater shedding after flowering among the Upland varieties, so that 
2 e s3 /o /7 *s/ 7 /<* 2 / as // 
Fig. 1—Average rate of growth for 25 plants in each variety from June 26 to September 11, 1922. 
Pima matures more bolls than any of the Upland varieties. On the other hand* 
the greater number of Pima bolls is counterbalanced by the larger size of the 
Upland bolls. 
It will be seen from figure 3 that the relations of the varieties in flower pro¬ 
duction were much the same in 1923 as in the previous year. The Acala variety 
produced on 25 plants a total of 1,948 flowers during the active flowering period 
of 1922, with a daily average of 23.4, while in 1923 only 1,290 flowers were pro¬ 
duced, and the daily average was only 15.9. Such a difference may be attributed 
to soil variations which were not distinguishable when the 25 plants were selected 
for record purposes. In 1922 many of the late bolls on some of the varieties 
failed to reach maturity on account of an early frost, whereas in 1923 the season 
was longer, and practically all of the bolls matured and were picked. This ac¬ 
counts, in part, for the lack of a correlation between the flower production and 
yields in 1922 and 1923. 
In 1922 the Durango plants continued flowering for 86 days, which was the 
longest period of active flowering recorded in either 1922 or 1923. In 1923, 
however, the active production of flowers by the Durango plants continued for 
