COTTON IN WEEVIL-CONTROL EXPERIMENTS oF 
20 all open bolis were picked, and the number cf good and weevil- 
damaged locks was recorded. Similar data were obtained for bolls 
which opened between August 20 and September 1 and between 
September 1 and September 18. 
A total of 211 bolls was picked from the two sections of rows on 
August 20. Of these bolls only 25 locks showed signs of weevil dam- 
age, representing 2.6 per cent of the total number of locks. On 
September 1, 613 bolls were picked, and 17.9 per cent of the locks 
were found to be damaged. Of 259 bolls picked on September 18, 
34 per cent had damaged locks. A total of 18.8 per cent of the locks 
was damaged ‘on the 1,083 bolls picked during the season. This 
weevil injury to bolls was much less than occurred in the other 
experiment on the cotton planted on the same date but between the 
earlier plantings. As shown in Table 11, the May 12 planting in 
the comparison of successive adjacent plantings had 33.9 per cent 
of all the locks damaged by weevils instead of 18 per cent in the 
separate late planting. This shows that even a slight isolation of 
the late plants had a notable effect upon weevil infestation and the 
resultant injury to the crop. 
YIELDS FROM THINNED AND FROM UNTHINNED ROWS 
The late-planted cotton was picked on September 18, at which 
time all bolls had opened. The field was divided into two equal sec- 
tions by drawing lines across it at right angles to the rows, and the 
weight of seed cotton from each section of each row was recorded 
separately. The length of rows in each section was 100 feet. 
The row yields from this test are presented graphically in Figure 
7 in comparison with the row yields obtained from the successive 
plantings. The yields and number of plants per row in the late- 
planting test are given in Table 16. 
| The row yields of seed cotton indicate that soil conditions were very 
uniform throughout the field. Most of the difference in row yields 
resulted from imperfect stands, some of the rows having short sec- 
tions with no plants or with a very irregular stand. ‘This irregu- 
larity in stand interfered with an accurate comparison of the two 
systems of plant spacing, as some of the unthinned rows had fewer 
lants than some rows which had been thinned to two plants in a 
ll. The poorest stands occurred consistently on the outside rows 
of each block. As a 2-row planter was used it is probable that these 
thin stands were due to faulty operation of one side of the planter. 
In view of the better stands on the two inside rows of each block, a 
more accurate comparison of yields may be obtained from these rows. 
The total yield of seed cotton from the inside rows of the three 
blocks of unthinned cotton was 67.07 pounds, as compared with a 
yield of 61.97 pounds from the inside rows of the three thinned 
blocks. From these weights the mean yield of one 200-foot row of 
unthinned cotton was found to be 11.18+0.31 pounds, while the 
ee eels of an equal length of row of thinned cotton was 10.33 £0.45 
pounds. 
The difference in average yield of seed cotton between the unthinned 
rows and the rows which were thinned to two plants in a hill with 
hills 12 inches apart is less than twice the probable error, indicating 
that there was no significant difference in yield between the thinned 
