40 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE, 194 4 
There were 1.645 known diseased trees standing at the end of the 
fiscal year, plus 71 trees that had been pruned over a period of years 
and kept under observation. 
A revision of the quarantine embargo that prohibits the interstate 
movement of elms and elm material from the infected zone to outside 
points was under consideration at the end of the fiscal year. Some 
movement of nursery elms was authorized during the year under pre- 
cautionary restrictions and on an experimental basis. 
WHITE PINE BLISTER RUST CONTROL 
Control of the blister rust disease is essential to the maintenance 
of the white pine forests of the United States. The accomplishments 
of the last 25 years are reflected in the amount of lumber available 
for war purposes and in the young growth for the next forest crop. 
Stands of white pine initially protected from blister rust in the earlier 
years of the control program are being harvested, and the young 
growth now receiving protection by eradication of ribes, alternate host 
plant for blister rust, will provide lumber for the future. Over 2 
billion board feet of white pine lumber were used during each of the 
last 3 years in connection with the war program. Accelerated cutting 
of white pine caused by war demands continued during 1943, and the 
need for adequately protecting the young growth, which is soon killed 
by blister rust, becomes of increased importance in providing for 
future crops of this valuable wood. 
EFFECT OF WAR ON CONTROL PROGRAM 
Conditions resulting from the war emergency continued to handicap 
the control program and to increase the difficulties of field operations, 
although some regions experienced less trouble than others. There 
were varying degrees of labor shortages in different areas, and a 
scarcity of many items of supply and equipment. The unavoidable 
restrictive orders and regulations resulting from these shortages, such 
as priority ratings, wage and labor stabilization policies, food and 
gasoline rationing, and restricted travel, greatly increased the problems 
and difficulties of carrying on field work. In some regions the general 
scarcity of labor in forest areas, or its employment on urgent war 
projects, resulted in greater use of blister rust crews on emergency fire- 
suppression work. Also, some of the permanent field personnel were 
temporarily detailed to aid the timber-production war project, and 
other urgent war activities were given assistance, when this could be 
done by employees without serious detriment to their regular work. 
Field work was adjusted to meet war conditions by using labor out- 
sidedrafi age, mostly young nun from L6to L7 years of age, hy tempo- 
rarily releasing men for farm work, by restricting travel and the use 
of equipment and supplies t<» bare essentials, by adopting a holding 
program for the duration of the war. by revising work schedules to 
maintain control on protected an as. by giving priority to areas requir- 
ing rework, and by assisting other war projects wherever practicable. 
PROGRESS OF CONTROL work 
There are about 2<S million acres of white pine control area in the 
United state-. This area fluctuates from year to year, being de- 
ores ed by Logging] inc. and other Causes and increased by natural 
