GROWTH OF FRUITING PARTS IN COTTON PLANTS* 
By R. D. Martin and W. W. Ballard, Assistants, and D. M. Simpson, Junior Agron¬ 
omist, Office of Acclimatization and Adaptation of Crop Plants and Cotton-Breeding 
Investigations, Bureau of Plant Industry, United States Department of Agriculture 
INTRODUCTION 
The rate of development of the cotton plant and especially of the 
fruiting branches, deserves more consideration in connection with 
studies of cultural methods and weevil-control problems. 
During the past three years data have been recorded on the order and 
rate of appearance and growth of floral buds, the sequence of flowers, 
and the growth of bolls. These studies have been carried on under 
different conditions and upon different types of cotton, as indicated 
in the following outline: 
1. Grown under the dry atmospheric conditions of the irrigated 
valleys of Arizona: Pima variety of the Egyptian type, Upland 
varieties of Lone Star, Acala, and Durango. 
2. Grown under drought conditions on the “Black Land” belt near 
Greenville, Tex.: Lone Star. 
3. Grown under conditions of high humidity at James Island near 
Charleston, S. C.: Sea Island and Meade. 
Thus it is possible to make comparisons of corresponding phases of plant 
growth and development with different types of cotton under a wide 
range of environmental conditions. 
The records summarized in the following tables show a very close 
agreement in the rate of appearance of floral buds and blooms between 
distinct species and types of cotton grown under different conditions. 
Considerable variation was observed between varieties in the period of 
development of the floral bud and in the interval from date of flowering 
to boll maturation. This indicates the importance of considering the 
relation of varietal and environmental factors to the growth rate. 
PRODUCTION OF THE FRUITING BRANCHES 
The main stalk of the cotton plant is formed by the development of 
successive internodes. At each node two buds are normally developed, 
an axillary bud which produces the vegetative branch and an extra- 
axillary bud which produces the fruiting branch. The axillary bud 
stands just above the middle of the base of the subtending leaf and 
usually remains dormant except on the first few nodes at the base of the 
stalk. The extra-axillary bud is developed to the right or left of the 
axillary bud. The specialized nature of the axillary and extra-axillary 
buds and the tendency for each to develop on definite groups of nodes 
1 Accepted for publication May 3, 1923. 
(* 9 S) 
Journal of Agricultural Research, 
Washington, D. C. 
afs 
Vol. XXV, No. 4 
July 28, 1923 
Key No. G-321 
