8 
BUREAU OF PLANT QUARANTINE 
[Jan.-Mar. 
Caution. — Observe the precautions mentioned in 1, A. 1. 
Season. — This treatment must not be used when adult beetles are present. 
Equipment. — Strips of 24-gage galvanized iron, 10 inches wide and of the proper 
length, are required. (See table 1.) 
Table 1. — Size of collar 
Diameter of ball to be dug 
(inches) 
Diameter 
of collar 
Length of 
collar 
Diameter of ball to be dug 
(inches) 
Diameter 
of collar 
Length of 
collar 
12 or less 
Inches 
18 
21 
27 
30 
Feet 
5H 
m 
8 
9 
9H 
24 
Inches 
36 
39 
42 
45 
48 
Feet 
10H 
11H 
12 
13 
14 
14 
25-27 
18 
28-30 
20 . 
33 
22 
33 
36 
Condition of plants. — Dilute carbon disulphide is least injurious to roots when 
the plants are dormant or semidormant, and treatment should be applied at that 
time. 
Dosage. — The dilution depends upon the probable temperature of the soil 
during the 48 hours following application, and must be determined by the Treating 
Division in accordance with table 2. 
Table 2. — Dilution schedule 
Minimum soil temperature 6 inches below the surface (° F.) 
Miscible 
carbon di- 
sulphide per 
10 gallons 
of water 
Schedule no. 1—40-50 
Schedule no. 2—50-60 
Schedule no. 3—60-70 
Cc 
The concentration of the emulsion must not be greater than is necessary, as 
this may injure the plants. 
The dosages which must be applied under different conditions are given in 
table 3 or table 4. 
Table 3. — Dosage for circular collars 
Diameter of col- 
lar (inches) 
Water 
Miscible carbon disul- 
phide 
Sched- 
ule 
no. 1 — 
40-50° 
F. 
Sched- 
ule 
no. 2— 
50-60° 
F. 
Sched- 
ule 
no.3— 
60-70° 
F. 
Gallons 
Cc 
Cc 
Cc 
12 
2.0 
14 
11 
9 
15 
3.0 
20 
17 
14 
18 
4.5 
31 
26 
20 
21 
6.0 
41 
34 
27 
24.. 
8.0 
55 
45 
36 
27.. 
10.0 
68 
57 
45 
30 
12.0 
82 
68 
54 
Diameter of col- 
lar (inches) 
Water 
Miscible carbon disul- 
phide 
Sched- 
ule 
no. 1— 
40-50° 
F. 
Sched- 
ule 
no. 2— 
50-60° 
F. 
Sched- 
ule 
no. 3— 
60-70° 
F. 
Gallons 
Cc 
Cc 
Cc 
33 
15.0 
102 
85 
68 
36 
17.5 
119 
99 
80 
39. 
21.0 
143 
119 
95 
42 
24.0 
164 
136 
108 
45 
27.5 
187 
156 
125 
48 
31.5 
215 
179 
143 
