80 ANN! \l. REPORTS 01 DEPARTMENT OF AGRICULTURE, 1 
sugar pine in the Sierra Nevadas was extended 13 miles. This newly 
discovered infection contains 310 cankers in 77 trees. Ii apparently 
became established there in l'.MI. Rusl infection on pine is now 
nearly -J-"' 11 miles south of the Oregon-California border. 
Blister rusl also was found east and south of previously known 
limits of spread in the Rocky Mountain region. An infected white- 
bark pine was found on Camel i an Creek on the _ I the Mount 
Washburn control unit in Yellowstone National Park. Infected pines 
were also found for the first time in Powell County, Mont., and 
Adams County, Malm. Ribes containing blister rust infection were 
found for the first time in Fergus and Wheatland Counties, Mont, 
and Big Horn County. Wyo. 
Barberry Eradication to Control Stem Rust 
Broad areas freed of barberries 
Black stem rust infection in grains was light in 1951, with damage 
confined chiefly to crops growing near barberry bushes. 
Barberry eradication for the control of this rust continued in co- 
operat ion with the State- of Colorado, Illinois, Indiana. Iowa. Michi- 
gan, Minnesota, Missouri, Montana. Nebraska, North Dakota. Ohio, 
Pennsylvania, South Dakota. Virginia, Washington, Wesrt Virginia, 
Wisconsin, and Wyoming. 
State Departments of Agriculture, County Boards of Supervisors, 
the Extension Service, and the Agricultural Experiment Station- in 
the L8 States where eradication activities are performed were the 
principal cooperators in this work. Landowner.- furnished labor and 
materials in many instances. The value of funds and services con- 
t ributed by cooperating agencies exceeded $262,000. 
Eradication work was concentrated principally in areas where 
barberry bushes had previously been a factor in spreading rust. In- 
itial work was done in Missouri. Pennsylvania. Virginia, Wes( Vir- 
ginia, and Washington. 
These ope rat ion- resulted in the destruction of nearly 14% million 
barberry bushes on L,500 new and 2,000 reinfected premises in 324 
counties. Twenty five percent of the properties reworked showed 
new growth. Eight thousand former barberry sites were rechecked, 
of which received their final reinspection. Some reseeding had 
occurred from fruiting bushes on 65 percent of the properties. Sur- 
vey crews engaged in this work covered 24,200 square miles. Areas 
totaling 22,000 square miles were placed in a maintenance status, and 
in the future will require only sufficient work to maintain them in a 
ba rberrj free condit ion. 
M ind-spread <>/ rust spores traced 
Slide-exposure stations located in 27 States helped to chart the 
movement of wind borne stem rust spores during the growing season. 
rveys showed race L5B of wheat stem rusl is 
w idely distributed and well established as far south ascent ral Mexico. 
Race 7 of oat stem rust is also widely distributed. More than 1,100 
collections of stem rust from grain and barberry were examined at the 
Federal Rust Laborator} at the University of Minnesota. St. Paul, 
M uu. Fr United Suites eoilr.iM.n-. pace 15B was isolated from 
