July 28, 1923 
Growth of Fruiting Parts in Cotton Plants 
207 
(3) The average number of days between the production of successive 
fruiting branches was approximately three days, with none of the 
varieties showing significant differences. (See Table I.) 
(4) All the varieties, under the conditions represented, showed an 
average of about six days between the appearance of successive squares 
on the fruiting branch. (See Table II.) 
(5) The Pima variety in Arizona showed a tendency for the interval 
between the appearance of successive squares of the fruiting branches 
to lengthen as the season advanced. (See Table III.) 
(6) A comparison of the interval between the appearance of successive 
squares on the fruiting branches showed that the interval increases pro¬ 
gressively along the branch. This increase may be due to the fact that 
outer squares are produced later in the season when growth is slower. 
The intervals between squares that are produced at the same dates are 
approximately equal regardless of the positions of the squares on the 
branches. (See Table IV.) 
(7) The interval between appearance of a square and its date of flow¬ 
ering, termed the “square period/' showed consistent differences be¬ 
tween varieties. The square period for Sea Island was approximately 
33 days, for Pima 30 days, for Meade 28 days, and for Lone Star, Acala, 
and Durango 23 days. (See Table V.) 
(8) A tendency for the square period to lengthen as the season ad¬ 
vanced was noted on the Pima variety at Sacaton. (See Table VI.) 
This relation could not be determined in the other varieties since the 
data were not recorded for sufficiently long intervals. 
(9) A slight increase in the square period for each successive node of 
the fruiting branch was also found on the Pima cotton at Sacaton, but 
this is probably due to the squares being produced later in the season, 
and is not correlated with position on the branch. (See Table VII.) 
(10) Growth rates of floral buds of Lone Star cotton at Greenville, 
Tex., showed that the buds grew at a nearly constant daily rate until 
within about 3 days of flowering, when a more rapid growth rate was 
recorded. 
(11) The sizes of the floral buds at different ages indicate that they 
were not large enough to successfully develop weevil larvae until about 15 
days before flowering, or approximately 10 days after the squares appear. 
(12) The growth of Lone Star bolls in Texas was very rapid, the mean 
maximum length of 41 mm. being reached about 20 days after flowering. 
The early bolls were found to be larger, the later bolls being produced 
during a drought. Although smaller, the late bolls had a longer matura¬ 
tion period, 44.55 days, while the large early bolls showed a mean matura- * 
tion period of 42.57 days, or about 2 days less than the late bolls. 
(13) Data on the growth of Pima bolls in Arizona were determined by 
records of volume, green weight, and dry weight of growing bolls, at 
regular intervals after flowering. The results show that the mean maxi¬ 
mum volume per boll, 14 cc., was attained in 25 days after flowering; 
that the mean maximum green weight per boll, 13.4 gm., was attained 
in about 40 days; and that the mean maximum dry weight per boll, 3.8 
gm., was attained in about 50 days. 
(14) A range in the period of maturation from 45 days to 80 days 
was observed on normal Pima bolls in Arizona in 1921. The period of 
maturation was found to lengthen for bolls of later flowering dates. 
