1939] SERVICE AND REGULATORY ANNOUNCEMENTS 55 
Table 3. — Dosage for square collars 
Diameter 
of ball to 
be dug 
(inches) 
Length 
of side 
of col- 
lar 
"Water 
Stock carbon disulfide 
emulsion 
Diameter 
of ball to 
be dug 
(inches) 
Length 
of side 
of col- 
lar 
Water 
Stock carbon disulfide 
emulsion 
Sched- 
ule 
No. 1 
40°-50° 
F. 
Sched- 
ule 
No. 2 
50°-60° 
F. 
Sched- 
ule 
No. 3 
60°-70° 
F. 
Sched- 
ule 
No. 1 
40°-50° 
F. 
Sched- 
ule 
No. 2 
50°-60° 
F. 
Sched- 
ule 
No. 3 
60°-70° 
F. 
Cubic 
Cubic 
Cubic 
Cubic 
Cubic 
Cubic 
centi- 
centi- 
centi- 
centi- 
centi- 
centi- 
Inches 
Gallons 
meters 
meters 
meters 
Inches 
Gallons 
meters 
meters 
meters 
12 or less... 
18 
5.5 
37 
31 
25 
24 
36 
22.5 
153 
128 
102 
14 
21 
7.5 
51 
43 
34 
25-27 
39 
26.0 
177 
148 
118 
18 
27 
30 
33 
12.5 
15.5 
19.0 
85 
106 
129 
71 
88 
108 
57 
70 
86 
28-30 
42 
45 
48 
30.5 
35.0 
40.0 
208 
238 
272 
173 
199 
227 
139 
159 
182 
20 
33 
22 
36 
Period of treatment. — The soil must not be disturbed for 48 hours. 
Period of digging. — The plants must be dug within 3 days after the com- 
pletion of the treatment. 
Varieties of plants. — The varieties which have been treated successfully by 
this method are given in Technical Bulletin 478. 
Preparation of plants. — The surface of the soil about the base of the plant 
must be practically level ; treatment must not be applied on a slope which 
cannot be leveled without filling. Weeds and debris must be removed from 
the surface of the soil. It is advisable to tie low-hanging branches so they 
will not dip into the treating solution. After the size of the ball to be lifted 
with the plant has been determined, a galvanized-iron collar of the proper size 
is placed about the base of the plant and forced to a depth of 3 inches into 
the soil. The soil must be firmed carefully on each side of the galvanized iron 
to prevent seepage. 
Application. — The quantity of treating solution to be used must be determined 
from tables 2 and 3. The required quantity of stock emulsion is added to water 
and mixed well. Then the solution is poured into the collar, avoiding splash- 
ing or unnecessary disturbance of the soil. Pouring the solution on a spade 
will be of considerable help. A record must be made of the time required 
for the treating solution to disappear from the surface. Drainage conditions 
must be such that the solution does not disappear from the surface in less than 
10 minutes or more than 5 hours. An examination must be made after the 
treatment has been applied to determine the uniformity of penetration. 
Handling plants after treatment. — The inspector must be sure that a ball of 
soil no larger than that originally planned is removed with the plant. 
(2) LEAD ARSENATE TREATMENT 
Season. — Treatment must be applied by July 1. Plants may be certified 
when the period of treatment is completed, and until the following June 15. 
Condition of soil. — The soil must be friable and in good tilth. This treat- 
ment is recommended only for soils that are slightly acid or neutral in reaction. 
Dosage. — Thirty-five pounds to each 1,000 square feet, or 1,500 pounds per 
acre. For subsequent re-trcatnients, the quantity required to restore the origi- 
nal concentration, as determined by chemical analyses, must be applied. 
Period of treatment. — Plants in plots treated initially must not be dug until 
October 1 ; those on re-treated plots may be dug on September 20. 
Application. — Lead arsenate must be thoroughly mixed and incorporated witli 
the upper 3 inches of soil. The ridge of soil between the plants in the rows 
and the soil about the base of the plants must be removed to a depth of 2 
inches and placed in the space between the rows of plants. Lead arsenate may 
be applied with a suitable distributor, or broadcast by hand. In-fore or after 
the hoeing operation is completed. Then the soil between the rows of plants 
must be cultivated three times. On the last cultivation, the cultivator is 
adjusted in such a manner that the treated soil is thrown toward the rows 
of plants. At least 3 inches of treated soil must be placed in the rows about 
the bases of the plants. 
