UNITED STATES DEPARTMENT OF AGRICULTURE 
In Cooperation with the Oregon and Washington Agricultural Experiment 
Stations 
DEPARTMENT BULLETIN No. 1434 
Washington, D. C. 
November, 1926 
CRANBERRY DISEASE INVESTIGATIONS ON THE PACIFIC COAST 
By Henry F. Bain, Assistant Pathologist, Office of Fruit Diseases, Bureau of 
Plant Industry 
CONTENTS 
Page 
Introduction , 1 
General considerations 1 
Climatic conditions 2 
Insect pests - _ 3 
Diseases 3 
Diseases of the cranberry plant— 3 
Red leaf spot and black stem spot 3 
Rose-bloom 4 
False-blossom 5 
Rust. — 5 
Venturia leaf spot 6 
Sclerotinia tip-blight 6 
Diseases of berries in the field 6 
Sclerotinia hard rot (cotton ball) and tip- 
blight 9 
Black spot of the fruit 8 
Minor field rots _.. 8 
Page 
Diseases of berries in storage 9 
Experimental work 9 
Methods 9 
Preliminary experiments 10 
Experiments to determine time and num- 
ber of applications of Bordeaux mix- 
ture 12 
Dusting experiments 16 
Cold-storage experiments 17 
Relation of weather to keeping quality 19 
Culture work with cranberry rot fungi 21 
Mature berries 21 
Green berries 26 
Summary 26 
Literature cited 28 
INTRODUCTION 
Although the diseases of the cultivated cranberry (Vaccinium mac- 
rocarpon) have been studied rather intensively since 1901, most of 
the work prior to 1922 was done in New Jersey, Massachusetts, and 
Wisconsin. This bulletin summarizes the results of a four-year study 
of cranberry diseases in the States of Oregon and Washington. The 
climate of the Pacific coast region is so different from that of the older 
cranberry-growing sections that important modifications in cultural 
[practices have been found necessary. Since cultural methods have 
[a very important relation to the pathological problems considered in 
[this work, it seems essential to outline briefly the general methods 
I at present followed in this region, with particular reference to the 
points in which these methods differ from those of the older cran- 
berry sections.- 
GENERAL CONSIDERATIONS 
Cranberry growing on the Pacific coast is a comparatively recent 
industry, its extensive development having been started in 1912 to 
1915 {/+)} The problem of determining the most successful varieties 
'The serial numbers {italic) in parentheses refer to "Literature cited, 
102485— 26t 1 
p. 28. 
