SPACING EXPERIMENTS WITH ACALA COTTON IN 
SOUTHERN CALIFORNIA 1 
By H. G. McKeever 
Assistant in Crop Acclimatization , Office of Crop Acclimatization and Adaptation 
Investigations , Bureau of Plant Industry , United States Department of 
Agriculture 
Different spacings of Upland cotton under irrigation in the Coachella Valley 
of California, which is located in Riverside County northwest of the Salton 
Sea, were compared in 1922 and 1923. Most of the cotton lands of the Coachella 
Valley are below sea level and the summer months are very hot. Though the 
extremely high temperatures prevailing during the summer months often cause 
excessive shedding of squares and young bolls, the season is so long that the 
plants are enabled to continue fruiting over a long period and large yields are 
usually obtained. Fields of Acala cotton planted as late as the tenth of June 
have sometimes yielded two bales to the acre. 
In the Eastern cotton belt, where the crop season may be very short on ac¬ 
count of dry weather, early frost, or boll-weevil damage, the ability of closer 
spaced plants to set a good crop in a short period is an important advantage. 
But in the irrigated valleys, where high temperatures interfere with the setting 
of an early crop, a long-continued fruiting period is necessary to obtain good 
yields. Under such conditions, it might be supposed that wide spacing, which 
permits the plants to grow large, would be an advantage. However, direct 
comparisons of spacings with the Acala variety of Upland cotton grown in the 
Coachella Valley indicate no advantage from wider spacing, even under the long- 
season conditions. 
The usual practice in the valley is to chop the cotton out from 12 to 16 inches 
in the row. Spacing experiments were conducted in 1922 and 1923 to compare 
plants spaced at 12 and 6 inches in the row with “unthinned” cotton. As a 
rather heavy rate of seeding was used, thick stands were obtained and some 
plants had to be removed from the unthinned rows in order to prevent crowding 
where the stand was “bunchy.” The plants were left 2 to 4 inches apart in the 
row, and this spacing has been designated as “2-inch” in the accompanying 
figures and tables. In thinning the 6 and 12 inch rows a measure was used and 
the plants were left as near these distances apart as the stand would permit. 
The designated spacings indicate the distance between the majority of the 
plants rather than the average distance between plants, which is somewhat 
greater on account of occasional short skips in the stand. The plant counts 
contained in Table III, however, show the spacings to be very close to that 
designated, except in the case of the 2-inch spacing. The 6-inch spaced blocks 
contain about twice as many plants as the 12-inch blocks, and the 2-inch blocks 
contain about twice as many plants as the 6-inch blocks, so that the average 
spacing of blocks referred to as “2-inch” was about 3 inches, though much of the 
cotton was as close as 2 inches. 
* Received for publication May 16,1924—issued November, 1924. 
Journal of Agricultural Research, 
Washington, D. O. 
(1081) 
Vol. XXVIII, No. 11 
June 14,1924 
Key No. G-444 
