2 BULLETIN 1365, IT. S. DEPARTMENT OF AGRICULTURE 
PROCEDURE IN TAKING FIELD NOTES 
^Comparisons, with the two varieties grown side by side in alternate 
blocks, were made in 1924 and 1925, and although different plots were 
used in the two years the general uniformity of the soil in this field 
permits two sets of plots to be used without noticeably affecting 
results. 
In both seasons the notes were obtained on 20 plants of each 
variety, selected in early June in different parts of the experimental 
plots in order that they might be as nearly representative of the 
field average of plants as was possible. The date of appearance of 
floral buds or " squares" and their position on the fruiting branches, 
the day on which any of these squares shed, the day on which a 
flower opened, and the day on which a boll opened were recorded 
throughout the fruiting season. From these records it is possible 
to trace the history of a square on any node of a fruiting branch from 
its appearance through the flowering stage to the opening of the 
boll or until it was shed, either in the square stage or as a young boll. 
The date of appearance of a square was determined by following 
the method described by Martin, Ballard, and Simpson (17) as the 
day on which the three bracts of a floral bud became visible as a small 
triangular "form" approximately one thirty-second of an inch in 
diameter. A boll was recorded as open or mature on the first day 
that the contents could be picked with ease. Shedding of squares, 
opening of flowers, and shedding of young bolls are definite features 
and were recorded on the day of occurrence. 
PRODUCTION OF SQUARES AND BOLLS ON PIMA AND ACALA 
PLANTS 
The period in which the daily records were made of the appearance 
of squares on the 20 plants of Pima and the 20 plants of Acala extended 
from June 15 to August 14, 1924, and from June 8 to August 15, 
1925. A few squares had already developed beyond the first stages 
on some of the plants when records were begun. These were recorded 
as "old" squares and are not included in discussions or tables relating 
to definite square periods, since the dates of appearance were 
unknown. The notes of square production were terminated in the 
middle of August, as the squares appearing after this time were 
considered as coming too late to develop into mature bolls before 
frost. 
The number of squares produced, squares that shed, and bolls that 
matured, as recorded on the 20 plants of each variety during the 
period of the experiment, are shown in Table 1 for 1924 and in 
Table 2 for 1925. 2 The data relating to the main stalks and to the 
vegetative limbs were separated in the tables, but these data are also 
combined to show complete plants. In 1924 the Pima plants on 
which notes were taken developed no vegetative limbs, and the data 
given in Table 1 are for complete plants represented by only the main 
stalks. 
2 In these tables the difference between the number of squares produced and the number that shed equals 
the number of flowers produced. The difference between the number of flowers and the number of bolls 
matured equals the number of bolls that shed. 
