BULLETIN 1365, U. S. DEPARTMENT OF AGRICULTURE 
There was no material difference between the two years in the 
number of squares produced by the main stalks, by the vegetative 
limbs, or by the complete plants of the Acala. The 20 plants of 
Pima in 1924, which produced no vegetative limbs, had fewer squares 
than were borne by the main stalks alone in 1925 and only slightly 
over two-thirds as many as were borne by the entire plants the latter 
year. Square shedding of entire Acala plants was slightly higher 
than on the Pima plants each year, with the shedding in both varieties 
considerably higher in 1925. 
A higher percentage of squares matured into open bolls on the main 
stalks and on the vegetative limbs of the Acala in 1925 than in 1924. 
The percentage of squares developed into mature bolls by the entire 
plants in this year was 5 more than in the preceding season. These 
plants had 39 per cent more open bolls than in 1924. Comparing 
the limbless Pima plants of 1924 with the main stalks of the following 
season, no difference is apparent in the proportion of squares maturing 
into open bolls; but combining the vegetative limbs with the main 
stalks of the 1925 plants lowers the proportion on these plants. 
However, with the increased number of squares borne on these plants, 
the number of bolls that matured was 27 per cent greater in 1925 
than in 1924. In 1924 the Pima plants matured 732 bolls and the 
Acala 267, and the following season 933 bolls matured on the Pima 
and 365 on the Acala plants. The tendency for a greater proportion 
of bolls to mature on Pima than on upland cotton has been reported 
in previous publications (o, 9, 10). 
Comparing vegetative limbs with the main stalks of each variety, 
the shedding of squares is seen to have been much greater and the 
percentage of squares developing into open bolls much lower on the 
vegetative limbs. In comparison 'with the main stalks, square 
shedding was relatively higher on the vegetative limbs of Pima than 
on those of Acala in 1925. 
The shedding of young bolls, or "flower shedding" as it is some- 
times miscalled, has been widely recognized as a factor materially 
affecting the yield of cotton. The shedding of the floral buds or 
squares is not so obvious as the shedding of bolls and generally has 
been disregarded as influencing yield, but indications of how serious 
square shedding often is may be found in Tables 1 and 2. If no 
square shedding had occurred, with the same rate of boll shedding, 
the number of bolls matured would have been increased at least 
60 per cent in each variety in 1924 and from 90 to 100 per cent in 
1925. That square shedding is not often noticed by the farmer 
was shown during the season of 1924 when many complaints were 
made by cotton growers of the Salt River Valley of Arizona regarding 
boll shedding, especially of the upland varieties, but nothing was . 
heard regarding the loss of squares, although square shedding was 
prevalent throughout the valley. Again in 1925, with a still higher 
rate of square shedding at Sacaton and at least as much square 
shedding in the Salt Kiver Valley as in the preceding year, no refer- 
ences were made to the loss sustained from this cause. Even boll 
shedding was not referred to by many growers in 1925, being less 
than in previous years and more evenly distributed throughout the 
season. 
The shedding of squares on the two varieties, recorded in periods 
of days between the appearance and the shedding of the squares, 
