54 BUREAU OF ENTOMOLOGY AND PLANT QUARANTINE [April-June 
center of the fruit and shall be maintained at or above that temperature for the 
last 6 hours of such treatment. 
No specifications as to the exact methods and equipment for obtaining these 
conditions are prescribed. Available information clearly indicates that by the 
application of dry heat the required temperatures cannot be reached without 
injury to the fruit. To prevent such injury it is necessary to maintain a very 
high humidity throughout the period of treatment. In the tests where suc- 
cessful performance was obtained, live steam as the source of heat was applied 
in such a way as to secure as nearly as possible a uniform distribution of 
steam-heated air so directed as not to discharge directly on the fruit. The 
air temperature ranged from 110° to 112° F., and the air was very moist. 
The fruit was held in field boxes stacked four boxes high and without special 
means of separating the boxes in each stack. The experiments indicate that 
the fruit should be sterilized after coloring, if this is necessary, and before 
packing for shipment, and then cooled down to a temperature around 45° as 
soon as possible after sterilizing. Wax or paraflme, either dry or in solution, 
should not be applied to this fruit either before or after sterilization. 
Such treatment is authorized in sterilization plants in the regulated area 
which are approved by the Bureau of Entomology and Plant Quarantine. The 
Bureau will approve only those plants which are adequately equipped to 
handle and sterilize the fruit. Such sterilization will be done under the super- 
vision of inspectors of the Bureau. These inspectors should at all times be 
given access to fruit while in process of sterilization. They will supervise 
the movement of the fruit from the car to and from the sterilizing rooms. 
While the results of the experiments so far conducted have been successful, 
it should be emphasized that inexactness and carelessness in operation may 
result in injury to fruit. In authorizing the movement of fruit sterilized in 
accordance with the above requirements, it is understood that the Department 
does not accept responsibility for fruit injury. 
Avery S. Hoyt, 
Acting Chief, Bureau of Entomology and Plant Quarantine. 
ANNOUNCEMENTS RELATING TO WHITE-PINE BLISTER RUST 
QUARANTINE (NO. 63) 
June 3, 1938. 
WHITE-PINE BLISTER RUST QUARANTINE REGULATIONS MODIFIED 
(Press notice) 
All restrictions on the interstate movement of five-leaved pines — except to 
points in two pine-growing regions in which the blister rust has not been found, 
one in the West and the other in the Southeast — will be lifted, it was an- 
nounced by the Secretary of Agriculture today, in a modification of the white- 
pine blister rust quarantine regulations, which becomes effective July 1. 
An embargo is placed on the interstate movement of five-leaved pines into 
the Western States of Arizona, Colorado, Nevada, New Mexico, Utah, Wyo- 
ming, and part of California, and into the Southeastern States of Georgia, 
Kentucky, North Carolina, South Carolina, and Tennessee, from States other 
than these 11 entire States and from 10 northern California counties. 
When the earlier blister rust quarantines were enacted and for several years 
thereafter there were several additional regions with extensive areas of com- 
mercially valuable stands of five-leaved pines in which the rust had not 
appeared. The restrictions in effect were designed to prevent the artificial 
spread of the disease into such regions, and the quarantines, first enacted over 
20 years ago, have been effective in delaying the spread of the rust while 
control measures were being developed and applied. 
The rust has now become established, however, in most of the commercially 
valuable pine-producing areas of the country. It has been found in 25 States. 
Owing to this condition and the fact that the disease can, under favorable 
conditions, spread naturally from pines to Rides for a distance of 150 miles 
or more, it is believed there is no biologically sound basis for continuing the 
former restrictions. 
