BUREAU OF PLANT QUARANTINE 65 
TECHNOLOGICAL DIVISION 
The work of the Technological Division during the fiscal year 1933 was carried 
on cooperatively with other divisions and projects of the Bureau on problems 
relating to the sterilization of plants and plant products. 
A new form of cottonseed sterilizer for destroying pink-bollworm larvae in 
cottonseed and adapted to continuous operation in handling the seed as it comes 
through the gin was designed, built, and tested. The machine is so constructed 
that it can be heated by steam or, if a boiler is not available, a vaporizing burner 
of the type in common use for commercial operation can be used as a source of 
heat. In the tests the sterilizer was found to be efficient and economical and 
readily heated the seed to a temperature of 145° F., the temperature required for 
sterilization. 
A method of installing thermograph bulbs in cottonseed sterilizers was de- 
veloped which allows a more accurate determination of the temperature of the 
seed and also increases the efficiency of the machine. A special stream-lined 
bracket for holding the bulb was designed and installed in the conveyor in such 
a way that the bulb is buried in a mass of seed whenever the sterilizer is in opera- 
tion. This mass of seed prevents the escape of steam from the conveyor and 
results in more efficient operation. The cost of sterilization is reduced, as much 
less steam is used to perform the operation. 
In cooperation with one of the large cotton companies, a method of treating 
cotton lint was developed which consists in passing the lint through heavy steel 
rollers as it comes from the gins and before it reaches the press box. Careful 
tests showed that such treatment is effective in crushing all seeds which may be 
in the lint so that any pink bollworms present will be destroyed. The equipment 
costs approximately $250 installed, and the operating costs are about 1 cent per 
bale, as compared with a cost of $1 to $2 per bale for fumigation. 
A method for treating hardy perennial plants in pots was worked out in cooper- 
ation with one of the large nurseries. The concentration of lead arsenate sufficient 
to kill the larvae of the Japanese beetle, but low enough so that the plants would 
not be injured, was determined. A treatment was developed which is effective 
in destroying the larvae and which can be applied to most perennials without 
injur}-. In the tests with plants, only 6 varieties out of 61 showed injury. Several 
thousand individual plants were included in these tests. 
Analyses of the soil for lead arsenate in plots of growing plants, heeling-in 
areas, and plunging frames were made to determine the amount necessary to add 
to bring these areas up to the 1,500 pounds in the first 3 acre-inches. This lead 
arsenate content is necessary to insure that no live Japanese beetle larvae are 
present, so that the plants may be shipped outside the regulated area without 
danger of spreading the infestation. In all, 872 samples from 392 plots of growing 
plants, 317 plunging frames, and 34 heeling-in areas were analyzed. These 
comprised a total of 5,726,153 square feet, of which 3,358,271 square feet needed 
the addition of some lead arsenate to bring the content up to 1,500 pounds in the 
first 3 acre-inches. Analyses were made of plots in 22 different nurseries, of 
which 1 was in Delaware, 16 in New Jersey, and 5 in Pennsylvania. 
A treating tank for applying the hot-water treatment to bulbs, as required by 
both domestic and foreign plant quarantines, was designed, built, and tested, 
and proved to be more efficient than many of the tanks now in commercial use. 
Plans have been prepared for the construction of this equipment, and they will 
be furnished to bulb shippers when desired. 
A number of alterations and additions have been made to the car-fumigating 
houses along the Mexican border. Vacuum-fumigating equipment has been 
installed at four ports to treat small shipments of infested or suspected material: 
new doors have been built; a new roof was applied to the fumigatioi 
Nogales, Ariz., and numerous minor repairs have been made. 
Considerable service work and work of an advisory nature has been done with 
the other projects in the Bureau. 
TERMINAL INSPECTION OF MAIL SHIPMENTS OF^ PLANTS AND 
PLANT PRODUCTS 
During the fiscal year, the list of terminal inspection points in California for 
the inspection of plants and plant products, under the authority of the . 
March 4, 1915, was revised, as wrere also the Lists of plants and plant products 
subject to such inspection in Florida and Georgia. The details of these revisions 
are given in the Service and Regulatory Announcements of this Bureau. 
