60 
BULLETIN 1374, U. S. DEPARTMENT OF AGRICULTURE 
of June, a few days before blooming started. Treatment of the 
plats in the second group (plats 4, 8, 12, and 16) began in the latter 
part of July. At that time the first bolls were about three-fourths 
grown. In the third group (plat 18) poisoning began near the end of 
August, when the infestation averaged 2.96 worms per boll. Appli- 
cations were continued on all plats until nearly all bolls were open. 
In the beginning, records of infestation were obtained by examining 
blooms. But after bolls developed this record was replaced by boll 
examinations, which were made weekly. Figure 14 shows the devel- 
opment of the infestation in blooms in the plats of group 1 and the 
corresponding check plats. According to this record the treatment 
caused a very noticeable check in the infestation. 
The progress of boll infestation, by groups of plats, is shown graphi- 
cally in Figure 15. 
A general summary of the experiments is given in Table 48. These 
records show definitely that the infestation was reduced by poisoning. 
The earlier the treatment was commenced the greater the reduction 
obtained. Treatment begun very late had practically no effect, 
as shown in Group 3, plats 17 and 18. The sudden rise in numbers, 
of worms per boll in the plats of Group 2 (fig. 15) at the last examina- 
tion was due to scarcity of bolls. Very few bolls were left on the 
plats at this time. This, however, was an abnormal record, not 
comparing with the previous showing of the plats. In the table, 
therefore, the next to the last instead of the last examination is given 
for plats 13, 14, 15, and 16, to show the maximum reduction in 
infestation due to the treatment. 
Table 48. — Summary of 'poisoning tests, 1921 
nt 
Acres 
Date of application 
Num- 
ber of 
ap- 
plica- 
tions 
Pounds 
applied 
Infestation 
last 
examination 
Per- 1 
cent- 
age ; 
non- 
pick- 
able 
cot- 
ton 
Classification 
of lint 
samples 
Plat 
No. 
Treatme 
First 
Last 
Total 
Per 
acre 
Worms 
per 
boU 
Per- 
cent- 
age 
differ- 
ence 
1 
Check- __ 
ar- 
ar- 
ar- 
ar- 
ar- 
ar- 
ar- 
"of" 
"of* 
1 
1 
1.11 
1.11 
1 
1 
1.11 
1.11 
1.07 
1.07 
1.07 
3.46, 
1.92 44.5 
3.82 
2. 88 21 6 
3.22 
2.44 24 2 
4.04 
9.3 
3.3 
6.9 
5.3 
8.0 
6.0| 
7.7 
7.5 
11.0 
6.8 
9.0' 
4.5! 
14.8 
10.8 
6.7 
i 
n 
Middling. 
2 Calcium 
senate. 
3 Check-.. 
June 15 
Aug. 23 
16 
152.5 
9.5 

Strict middling. 
Do. 
4 Calcium 
senate. 
9 I Check... 
July 20 
Aug. 23 
... . 
84.75 
9.5 
Good middling. 
Do. 
10 Calcium 
senate. 
11 ; Check.. 
June 15 
Aug. 23 16 
124. 25 
7.8 
Do. 
Strict middling. 
12 Calcium 
senate. 
13 Check .. 
July 20 
Aug. 23 8 
84.75 
9.5 
3.72 
14.16 
» 1.66 
13.68 
i 1.52 
6.98 
6.8 
4.8 
2.38 
4.18 
3.14 
7.9 
""60.1 
"~58.~7 
"'2.1 
"Ih'.l 
"24."9 
Do. 
Do. 
14 , Calcium 
senate. 
15 fJhfiRk 
June 25 
Sept. 14 19 
181. 25 
8.9 
Good middling 
Strict middling. 
16 
17 
Calcium 
senate. 
Check.. . 
Calcium 
senate. 
Check... 
Arsenite 
zinc. 
Check... 
Arsenite 
zinc. 
1.07 
2.16 
2.16 
0.66 
0.66 
0.66 
0.66 
July 24 
Sept. 14 j 12 112.0 
8.7 
Good middling. 
18 
5 
Aug. 26 
Sept. 30 9 229. 
11.8 
Strict middling. 
6 
7 
June 15 
Aug. 23 16 134.0 
12.7 
Good middling. 
Strict middling. 
8 
July 19 
Aug. 23 
8 
60.0 
11.4 
Good middling. 
These were the next to last examination. 
