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UNITED STATES DEPARTMENT OF AGRICULTURE 
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Pentiees > é% Ry! eet b 
Washington, D. C. July 16, 1924 
PRUNE AND CHERRY BROWN-ROT INVESTIGATIONS IN THE 
PACIFIC NORTHWEST. 
By CHARLES Brooks and D. F. FisHer, Pathologists, Office of Fruit-Dtsease 
Investigations, Bureau of Plant Industry. 
CONTENTS. 
Page. Page 
TRO SRO NIKO Kass Cpe ee Ae eed ES Be OS er a 1 | Spraying experiments on cherries___ 12 
Rosson Im fection: == 27s. byes er 2 Spraying experiments in 1915__ 12 
Ha OVEN DANE CG sea Sh al cee 3 Spraying experiments in 1916_~- 13 
Time relation of apothecia, blossoms, Spraying experiments in 1917__ 13 
and blossom infection. ——~-~—__—__ 3 Spraying experiments in 1918_- 15 
Relation of plowing, cultivation, and Spraying experiments in 1919__ 16 
eharacteror Spi 2 Sot kD 3 Summary of spraying experi- 
ERO TIRE CC GIO Mes ne Se 4 ments on cherries—.-——-—__-— 16 
Spraying experiments on prunes____ 4 | Recommendations for the control of 
Spraying experiments in 1915__ 4 brown-rot of .cherries-2_+.--. _-= aL r¢ 
Spraying experiments in 1916__ Ge reCpAaragOnTOk SPLayse= = ee 17 
Spraying experiments in 1917__ 7 Self-boiled lime-sulphur___-__~_~ 17 
Spraying experiments in 1918__ 8 Bordeaux mixcure= = =e ee 18 
Spraying experiments in 1919__ 9 Lime-sulphur solution ________~_ 19 
Summary of spraying experi- Rosin-hshoil! soap 19 
MCUESEOM “prunes 2 10 SS Bra ee a a 20 
Recommendations for the control of Spraying: scheduléyy_ 20_ 3 Bt a= 20 
brown-rot of prunes___._______— SLi hee Snr Taig Vos 2s 2 ho SS a ce es 21 
INTRODUCTION. 
; The present bulletin reports the results of five years’ investigation 
* of prune and cherry brown-rot in the lower Columbia and Willamette 
Valleys of Washington and Oregon. The climatic conditions of the 
section are less favorable to the development of brown-rot than those 
of the Eastern States, but more favorable than on the eastern slope 
of the Cascades or in the Rocky Mountain region. The average 
annual rainfall is about 45 inches (weather records for Portland, 
Oreg.), but more than 35 inches of this falls in the six months be- 
ginning with October and ending with March, about 5 inches during 
88674°—24—1 
