40 BULLETIN 1473, U. S. DEPARTMENT OF AGRICULTURE 
in which plants spaced 12 inches apart have produced significantly 
more cotton than plants spaced less than this distance. 
The experiment of 1921, in which only 6-inch and 12-inch spacings 
were compared, showed a ’sionificantly higher yield from the 6-inch 
spacing. 
Bat 1922 there was no outstanding difference in yield in the com- 
parison of 6-inch and 12-inch spacings with unthinned rows. In one 
experiment the 12-inch spacing produced more cotton than the closer 
spacings, but in another comparison of the same spacings the 6-inch 
yielded slightly more than the 12-inch spacing or the unthinned rows. 
Cotton planted in hills 21 inches apart gave much higher yields from 
rows in which several stalks had been left in the hill, as compared 
with only one plant in a hill. 
In 1923 there was a very definite tendency toward higher yields 
from the 6-inch spacing and the unthinned rows compared with 
_ wider spacings. Seven experiments were made in 1923, of which 
only one showed a tendency toward higher yields from rows in which 
the plants were spaced 12 inches apart. 
Two experiments were made in 1924. One showed significantly 
higher yields from unthinned rows, as compared with chopped rows. 
In the second experiment the rows with two plants every 12 inches 
produced slightly more cotton than the rows that were left unthinned. 
The difference in this case was not significant and would not pay for 
the cost of chopping. 
Five experiments were made in 1925, and in each one the closer 
spacing showed a significantly higher yield than the wider spacing 
with which it was compared. The summer of 1925 was the driest 
during the 5-vear period covered by this report, and the stored mois- 
ture in the soil was less in the spring of 1925 than in any year from 
1921 to 1925. Higher yields from the closer spacings in 1925 were 
consistent and significant. 
It has often happened that there was little or no difference between 
the yields of the unthinned rows and the 6-inch spaced rows. ‘The 6- 
inch spacing is undoubtedly a desirable distance between cotton plants, 
but is one that is difficult to obtain under field conditions. The gen- 
eral results of these experiments indicate that the yield of cotton “ 
more likely to be reduced than increased by chopping. 
The saving of labor or expense is in favor of unthinned cotton. 
It is recognized, however, that in some districts the cotton requires 
weeding and that weeding and chopping to a stand are often com- 
bined in one operation. Hence, leaving the rows unthinned may not 
save the entire cost of chopping. 
Under the usual conditions at Grosnaille the yield of cotton 
appears to be closely associated with the number of plants to the 
acre. Of course, it 1s possible for the plants to be overcrowded or 
for seasons to be so dry that the plants do not reach the fruiting 
stage. But in short periods of favorable conditions more bolls are 
set in the close-spaced rows 
The number of plants that can safely be left in the row is a ques- 
tion that must be determined by the grower for his various types of 
soil and different climatic conditions. These experiments show that 
much closer stands of plants than are now customary may be left in 
the rows, with added chances for increased yields. Although close 
