48 BUREAU OF ENTOMOLOGY AND PLANT QUARANTINE [April-June 
(k) soil in and around coldframes, plunging beds, and heeling-in areas 
* * * 
(1) Lead arsenate treatment 
Season. — The treatment must be applied before August 1 if the land is to be 
used in the fall. 
Condition of soil. — The soil must be friable and in good tilth. 
Dosage. — Twenty-six pounds to each 1,000 square feet, or 1,100 pounds per 
acre. For subsequent re-treatments, the quantity required to restore a concen- 
tration of 1,100 pounds per acre, as determined by chemical analyses, must be 
applied, except that determination by chemical analyses of a concentration of 
1,000 pounds per acre will be acceptable without re-treatment. 
Application. — The lead arsenate must be thoroughly mixed and incorporated 
with the upper 3 inches of soil. 
Period of treatment. — Plants must not be placed on or in the soil thus treated 
until after October 1. 
* * * 
(M) TREATMENT OF PLANTS BEFORE DIGGING 
* * * 
(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 treatment 
is recommended only for soils that are slightly acid or neutral in reaction. 
Dosage. — Twenty-six pounds to each 1,000 square feet, or 1,100 pounds per 
acre. For subsequent re-treatments, the quantity required to restore a con- 
centration of 1 ; 100 pounds per acre, as determined by chemical analyses, must be 
applied, except that determination by chemical analyses of a concentration of 
1,000 pounds per acre will be acceptable without re-treatment. 
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 with 
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, before or after the hoeing 
operation is completed. Then the soil between the rows of plants must be cul- 
tivated 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. 
Varieties of plants. — The varieties of plants which have been treated success- 
fully by this method are given in Bureau of Entomology and Plant Quarantine 
Circular E-418! 
Safety zone. — Same as that prescribed in (k). 
Marking. — Same as that prescribed in (k). 
Done at Washington, D. C, this 25th day of April 1941. 
[seal] Lee A. Strong, 
Chief of Bureau. 
I Filed with the Division of the Federal Register May 1, 1941, 11 : 17 a. m. ; 6 F. R. 2225.] 
