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UNITED STATES DEPARTMENT OF AGRICULTURE 
BULLETIN No. 368 
Contribution from the Bureau of Plant Industry 
WM. A. TAYLOR, Chief 
Washington, D. C. PROFESSIONAL PAPER March 6, 1916 
BROWN-ROT OF PRUNES AND CHERRIES IN THE 
PACIFIC NORTHWEST. 
By CuHarites Brooks and D. F. Fisner, Office of Fruit-Disease Investigations. 
CONTENTS. 
Page Page 
BEA UCLION eck. Suerte Saree SS 1 | Summary and conclusion for prunes......... 8 
Blossom infection of prunes.........-..----- 2 | Blossom infection of cherries................. 8 
Sprayinsvexperiments:. 2-2... 22 2.225.2.2-422-- 4.)|. -Brown-rotioncherriess-24-. <= 222 5<-s-casea-6 Q 
BECO OL Prunes ae oc CS Sieg a= ence Ss 5 | Summary and conclusion for cherries......_. 10 
INTRODUCTION. 
For several years the growers of the lower Columbia and Willam- 
ette Valleys have had severe losses of their prunes and cherries. 
Among the causes have been a failure of the trees to set a full crop 
and a lack of keeping quality in the harvested fruit due to brown-rot. 
Occasional midsummer outbreaks of brown-rot have also occurred. 
In the spring of 1914 Mr. M. B. Waite, Pathologist in Charge of 
Fruit-Disease Investigations, examined some diseased prune blossoms 
from Vancouver, Wash., and was in correspondence with the growers 
concerning the cause of the prune trouble. He has furnished the 
following manuscript note covering these investigations: 
With a letter dated April 18, 1914, from Mr. Chapin A. Mills, Vancouver, Clarke 
County, Wash., addressed to the Department of Agriculture, specimens of spurs and 
twigs of the Italian prune (Prunus domestica), with dead and dying blossoms, were 
received, with an inquiry as to the cause and remedy for the bad condition of the 
blossoms, the dropping of the bloom and young fruit, and the widespread failure of 
the crop to ‘‘set” or hold its fruit. A few days later a similar set of specimens was 
received from the same district, and a number of inquiries, without specimens, reached 
us from Washington, Oregon, and California, including the Sacramento and Santa 
Clara Valleys, as to the cause of the failure of the prunes to set their fruit. 
Note.—This bulletin is intended particularly for the benefit of prune and cherry growers of western 
Washington and Oregon, but is of interest to growers of these fruits in other sections of the United States. 
It is also of scientific interest to plant pathologists in general. 
28838°—Bull. 368—16 
