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UNITED STATES DEPARTMENT OF AGRICULTURE 
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DEPARTMENT BULLETIN No. 1186 
Washington, D. C. A February 8, 1924 
WHITE-PINE BLISTER RUST IN WESTERN 
EUROPE. 
By W. Sruart Morr, Assistant in White-Pine Blister-Rust Eradication, Office of 
Blister-Rust Control, Bureau of Plant Industry. 
CONTENTS. 
Page. Page. 
Batrrocnehnon= =) 4 ost a 1 | Control measures recommended in 
Scope of the investigations________ Pe | SAD WNT) OY Sea a a Se ne es, Se ALT. 
Rtorrenirevinws = 9) =e so Srl 3 | Significance of HKuropean experience 
Susceptibility of blister-rust hosts__ 3 CO PAIN ericare ss: = Ses Sa ee 21 
Relation of white pines to European Economic aspects of the blister-rust 
FORESTRY 2 aS Ae aera 6 LOD eins Aeiere se ee Pee 2 25 
Importance of currants and goose- Summary of the blister-rust situa- 
RING eee ee oe Se te Se 9 On Ouro pe = 255 sk 26 
Damage to eastern white pine in European experience a warning to 
EEO ete Ss Se ES ata ACTIN CA eee ee a gs eee 28 
miterature; Cited2222 2— Sa 29 
INTRODUCTION. 
Following the outbreak of the white-pine blister rust in the north- 
eastern United States and in Ontario, Canada, foresters and patholo- 
gists sought a method of combat, and to this end European litera- 
ture was scanned for assistance (40). The European scientists who 
studied the causal fungus (Cronartium ribicola Fischer) had con- 
fined their research almost exclusively to its biology. Their inves- 
tigations as summarized in literature contain many suggestions for 
combating the disease, and they advance the principle of control by 
host separation but yield nothing definite on the practical applica- 
tion of control measures suited to American conditions. During the 
period from 1917 to 1921 the United States Department of Agricul- 
ture, in cooperation with the New England States, New York, Wis- 
consin, and Minnesota, conducted extensive experiments to develop 
methods of practical control of the disease under forest conditions. 
These experiments have fully demonstrated that under average 
forest conditions in the northeastern United States, white pine can 
1 The serial numbers (italic) in parentheses refer to “ Literature cited” at the end of 
this bulletin. 
55162°—24——-1 1 
