1942] 
SERVICE AND REGULATORY ANNOUNCEMENTS 
Treatment of Soil About the Roots of Plants 
m ***** * 
(1) TREATMENT OF PLANTS AFTER DIGGING 
******* 
(5) Methyl bromide fumigation 
Equipment. — An approved fumigation chamber equipped with vaporizing, air- 
circulating, and ventilating systems must be provided. 
Application. — After the chamber is loaded, the methyl bromide must be vapor- 
ized within it. The air within the chamber must be kept in circulation during 
the period of fumigation. At the completion of the treatment, the chamber must 
be well ventilated before it is entered and the plants removed. The ventilating 
system should also be in continuous operation during the entire period of re- 
moval of the fumigated articles. 
(i) Fumigation of plants, with or without soil 
(a) Temperatures, periods of treatment, and dosages. — The temperature of 
the soil (with bare root stock, the root spaces) and of the air for each type 
of treatment must remain throughout the entire period of treatment at the 
minimum specified in the following table, or higher : 
Temperature at least 
Period of 
treatment 
Dosage 
(methyl 
bromide 
per 1,000 
cubic feet) 
Temperature at least 
Period of 
treatment 
Dosage 
(methyl 
bromide 
per 1,000 
cubic feet) 
1. 73° F 
Hours 
2V 2 
2Y2 
3 
Pounds 
1H 
2 
2V 2 
2Y 2 
2y 2 
6. 54° F 
Hours 
4 
VA 
4 
4H 
Pounds 
2Y2 
2V 2 
3 
3 
2. 67° F 
7. 50° F 
3. 63° F 
8. 46° F 
4. 60° F 
9. 43° F 
6. 57° F... 
The dosage shall be for each 1,000 cubic feet including the space occupied by the 
load. 
(b) Preparation of plants. — The treatment is to be applied to plants with 
bare roots or in 14-inch pots or smaller, or in soil balls not larger than 14 inches in 
diameter nor thicker than 14 inches when not spherical. The soil should not be 
puddled or saturated and must be in a condition which in the judgment of the 
inspector is suitable for fumigation. The plants should be stacked on racks or 
separated so that the gas can have access to both top and bottom surfaces of pots 
or soil balls. While not essential that the balls be completely separated from each 
other they should not be jammed tightly together. 
(c) Packaged plants. — Boxed or wrapped plants in packages not more than 
14 inches in diameter may be fumigated at any one of the above nine tempera- 
tures, periods of treatment, and schedules. In order that the fumigant may have 
access to the roots and soil masses about the roots, the wrapping shall not be 
tightly closed. 
(d) Varieties of plants. — The list of plants, including greenhouse, perennial, 
and nursery-stock types treated experimentally, is subject to continual expansion, 
and, moreover, is too great to include in these instructions. 
The schedule for the fumigation of strawberry plants as specified in subpara- 
graph (5) (ii) of paragraph (1) of § 301.48b [page 14 of the mimeographed 
edition of circular B. E. P. Q. 499] remains the same as heretofore. 
(7 C. F. R. § 301.48; sec. 8, 39 Stat. 1165, 44 Stat. 250; 7 U. S. C. 161.) 
This supplement supersedes Supplement No. 1, revised, effective April 23, 
1942. 
Done at Washington, D. C, this 16th day of September 1942. 
P. N. Annand, 
Chief. 
[Filed with the Division of the Federal Register September 18, 1942, 11 : 42 a. m. : 7 F. R. 
7381.] 
