June 14, 1924 
Spacing Experiments v:it7i Acala Cotton 
1093 
Comparisons were not made between close spacings and large, rank, overgrown 
plants with many vegetative branches, which w r ould be expected to show a 
greater advantage for close spacing, so that the present comparison between no 
thinning or 2-inch spacing with spacings of 6 and 12 inches is believed to be more 
significant. The 6- and 12-inch spaced plants were not crowded and did not 
have large numbers of vegetative branches, but an earlier thinning of these blocks 
would have allowed more vegetative branches to develop, with the result of 
greater crowding and closing of the lanes between the rows, which undoubtedly 
tends to reduce the yields and would have given the 2-inch spacing an additional 
advantage. 
While large differences in yield between unthinned and wider-spaced plants in 
the irrigated valleys of the Southwest are not to be expected under conditions 
where both spacings are well grown, the ability of the close-spaced plants to set 
a good crop in a short time may often secure an advantage where the soil is not 
very well adapted to cotton culture, w’here the farmer is not familiar with the 
crop, or where irrigation is inadequate. Even if the greatest care is used in 
irrigation it is not to be expected that the plants can be kept in the best condition 
for the production of fruit throughout the entire season. Water is likely to be 
held off too long occasionally, which causes shedding, or may be applied too fre¬ 
quently, causing overgrowth and consequent shedding. The degree of this kind 
of damage is in proportion to the skill wdth which the farmer irrigates his cotton. 
On this basis it becomes apparent that the ability of the close-spaced plants to 
set more bolls during short periods of favorable conditions may also be of value 
in irrigated districts. This does not mean that good yields are not secured from 
the wide-spaced plants under favorable conditions, but that the chances of a full 
crop, especially under less favorable conditions apparently are better with close 
spacings than with wfide spacings, even under the long-season conditions of the 
irrigated vallevs. 
CONCLUSIONS 
Experiments under irrigation in the Coachella Valley of California of plants 
spaced approximately 2, 6, and 12 inches apart in the row indicate that no reduc¬ 
tion in yield occurs when plants are left as close as 2 inches in the row, and that 
occasionally increased yields may be obtained from 2-inch spaced plants, even • 
under long-season, weevil-free conditions. 
It also is indicated that plants spaced at 6 inches give equal or better yields 
than 12-inch spaced plants. However, since the 6-inch spacing is not convenient 
in field operations the practical alternatives are 2 plants together at 12 
inches or omitting the chopping operation entirely, except in thick stands, 
when some plants should be pulled out. 
In the first picking the yields were nearly the same for all spacings; in the 
second picking the 6 and 2-inch spacings yielded more than the 12-inch, the 
greatest increase being in the 2-inch spacing. 
Though unthinned cotton, or plants spaced as close as 2 inches in the row, is 
more crowded at first, which may result in a suppression of some of the lower 
fruiting branches, as well as of the vegetative branches, the crowding is lessened 
by the spreading apart of the plants as they become larger. This is in contrast 
with the behavior of plants that are widely spaced at first, which produce numer¬ 
ous vegetative branches and become more crowded as the season advances. 
Since even on the best soil and with the greatest care it is not likely that the 
plants can be kept in the best condition for the production and retention of 
fruit throughout the entire season, the ability of the close-spaced plants to set 
a crop rapidly during favorable periods is likely to prove of advantage even under 
the long-season, weevil-free conditions of the Southwest. 
