Vi PREFACE 
At present, circumstances do not permit the plant doctor 
to call in person or by letter to advise with every fruit- 
grower regarding his many problems. No experiment sta- 
tion can furnish bulletins that will answer the purpose in 
every detail. And up to the present there have been no 
American texts or reference books dealing wholly, and in 
some detail, with the diseases of fruits. It is hoped that 
this Manual will give to the fruit-grower such information 
on fruit diseases as is available to date. The authors realize, 
however, that the best possible book on fruit diseases cannot 
entirely meet the situation. Possibly the day will come when 
each neighborhood will be provided with its own plant doc- 
tor; until this time the advice must remain qualified. 
It may appeal to the critic that many technical details are 
included which will only confuse the grower. But the time 
has come when the grower and the plant pathologist must 
meet on an equal footing. No longer should the grower 
refuse to understand the philosophy of his operations. Any 
careful consideration of a disease involves the use of certain 
terms not common in the farmer’s vocabulary... The termi- 
nology of the plant pathologist should be no more bewilder- 
ing than that of the family physician or the veterinarian. 
To assist in an understanding of the usage of certain terms 
in the text, a glossary is appended. These terms may be 
found in dictionaries, but differences in the shades of mean- 
ing often lead to confusion. 
The grower is in the habit of grouping his troubles as well 
as his labor and projects. In his own mind he classifies diseases 
on the crop basis. Accordingly, only fruits are included in 
this Manual. It is hoped that other crops may be the sub- 
jects of similar manuals in the future. In seeking guidance 
on any disease-control problem, the fruit-grower groups 
fruit diseases according to the fruit. It has therefore seemed 
best to discuss the diseases of a given fruit in one place. 
The arrangement of the fruits in the text, that is, alphabet- 
