44 ANNUAL REPORTS OF 
distributed in several counties In which only one or a few pine Infection centers 
had been pre^ lously known. 
in ih" Lake States regi< □ (83,877 acres were cleared of 39,219,729 RHx - dor- 
Log L935, in cooperation with the Forest Service, the [ndian Service, and the 
States concerned, as recorded in table 16. This Includes 23,992 acres that were 
given a second working and 1,400 acres that received a third working. From 
L918 i" L935, Inclusive, 95,763,280 Ribes wen- destroyed on 1,218,451 acrt 
land, or over a fourth of the control area. This region originally supported one 
of the most extensive and finest virgin white pine forests in the country. While 
nearly all the virgin pine has been cut, there remain over 1,250,000 acrt 
valuable second growth, and white pine Is also being used extensively to reforest 
Large areas <"i' forest land that mighl otherwise remain in an unproductive 
condition. 
NORTHEASTERN STATES NOW LARGELY INITIALLY PROTECTED 
In the Northeastern States 684,285 acres were brought under initial p 
tion in 1935, ilif Federal, State, and local governments working in cooperation, 
and 440,913 acres were given a second coverage. In this region control opera- 
tions have been in progress Longer than in any of the other white pine regions 
of the country, and five-sixths of the white pine area has been brought under 
initial protection. Since the work was tirst started. 160,808,360 Ribes have been 
destroyed on 12,115,813 acres of white pine land. Including L,942,913 acres that 
have been given a second working. This work has effectively brought the 
disease under control on these areas. 
RIBES ERADICATION IN SOUTHERN APPALACHIAN REGION 
In the Appalachian region initial control work, which was net started on an 
extensive scale until the emergency work programs were undertaken in 1983, has 
now been completed for the present on the white pine areas of Kentucky and 
South Carolina. In the other Appalachian States the work has made good 
progress during the year, a total of 3,(80,622 Ribes having been eradicated from 
'.''.»!•. 1 Pi acres. In general. Ribes are much less numerous than in the other white 
pine regions of the country, and this makes it possible to work a much Larger 
acreage per man-day. As the disease is gradually spreading southward, the 
timely eradication of Hikes should keep the white pine areas in condition tor 
the safe production of white pines as a timber crop at small i 
The rust was found in 1935 on Ribes and on white pine farther south in 
Augusta County. Va., than was heretofore known, it is now quite generally 
distributed in several of the infected counties of Virginia and West Virginia. 
One important finding was a heavy blister rust infection on European black 
currants in Norbeck, about 1- miles north of the District of Columbia, in 
Montgomery County, Md. 
NURSERY PROTECTION AND ( I LTIVATED BLACK CURRANT ERADICATION 
In order to prevent the distribution of the disease through the movement of 
Infected white pine planting slock, />'///< .s-free /.ones are established and main- 
tained around nurseries, in cooperation with the owners This work make-, it 
possible for purchasers of white pine ornamental or forest planting stock to 
obtain trees raised under conditions that assure their freedom from blister-rust 
infection, in establishing these zones all Ribes are eradicated within 1,500 feet 
and all cultivated black currants within 1 mile of the nurseries. These /.ones 
are kept free of Ribes by yearly Inspection and reworking where accessary. 
During 1935 this work was carried on around 59 nurseries, thus affording protec- 
tion lor millions of white pines being grown for forest and ornamental planting. 
The European or cultivated black currant {Ribes nigrum) Is more susceptible 
to blister rust than any other species of Ribes and Ls one of the chief agents in 
itv long-distance spread .-md local establishment. The eradication of this plant 
in white pine region- i- .1 general control measure that will he of material aid 
in checking the spread Of the disease. The cultivated black currant Bhould not 
be grown in white pine regions, it Is an Introduced plant that seldom escapes 
from cultivation, ami its economic Importance and value, as compared with that 
of the white pine-. i~ \ er\ -mall. During the past season 51,908 of these plants 
were eradicated in the eastern white pine regions. In the wt -tern white pine and 
sugar pine regions all such black currants as have been found were eradicated 
several \ ears ago. 
