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30 BUREAU OF ENTOMOLOGY AND PLANT QUARANTINE [April-June 
and Plant Quarantine by § 301.48-6, Chapter III, Title 7, Code of Federal 
Regulations [regulation 6 of the rules and regulations supplemental to Notice of 
Quarantine No. 48], subsection (1) (5) of § 301.48-b 1 [on page 13 of the mimeo- 
graphed edition of circular B. E. P. Q. 499, issued June 9, 1939] is hereby further 
modified effective April 23, 1942, to read as follows: 
(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 removal 
of the fumigated articles. 
(i) Fumigation of plants, with or without soil 
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 treat- 
ment 
Dosage 
(methyl 
bromide 
per 1,000 
cubic feet) 
Temperature at least 
Period 
of treat- 
ment 
Dosage 
(methyl 
bromide 
per 1.000 
cubic feet) 
1. 73° F 
Hours 
01 
2H 
3 
Pounds 
2 
2H 
2H 
5. 57° F 
Hours 
Wi 
4 
4H 
Pounds 
2U 
2H 
2H 
2. 67° F 
6. 54° F 
3. 63° F 
4. 60° F 
7. 50° F 
The dosage shall be for each 1,000 cubic feet including the space occupied by 
the load. 
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. 
Packaged plants. — Boxed or wrapped plants in packages not more than 14 inches 
in diameter may be fumigated at any one of the above seven temperatures, per- 
iods 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. 
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 subsection 
(1) (5) (ii) 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, dated August 6, 1941. 
Done at Washington, D. C, this 21st day of April 1942. 
P. N. Annand, 
Chief. 
I This section was oricinally issued as § 301.48a 
