UNITED STATES DEPARTMENT OF AGRICULTURE 
Rfe BULLETIN No. 543 
f?J/» Contribution from the Bureau of Plant Industry 
Contribution from the Bureau of Plant Industry 
WM. A. TAYLOR, Chief 
Washington, D. C. 
1917 
CONTROL OF PEACH BACTERIAL SPOT IN 
SOUTHERN ORCHARDS. 
By John W. Roberts, Pathologist, Fruit-Disease Investigations. 
CONTENTS. 
Introduction 1 
Description of the disease 2 
Cause of the disease 3 
Page. 
Varietal susceptibility 3 
Control experiments 4 
Summary and conclusions 7 
INTRODUCTION. 
In most of the peach-growing sections of the eastern half of the 
United States the disease commonly called bacterial spot, or bacteri- 
osis, is becoming increasingly important, especially in the more 
southerly sections. It is impossible to give any estimate of the 
damage which it causes annually, (1) because it is mainly a disease 
of the foliage and (2) because of its great seasonal variation. It has 
been reported as occurring in practically the whole of the eastern 
United States, including Massachusetts, Connecticut, New Jersey, 
Delaware, Maryland, Pennsylvania, Michigan, Illinois, Indiana, Ohio, 
Kentucky, Tennessee, Virginia, North Carolina, South Carolina, 
Georgia, Alabama, Arkansas, Missouri, Nebraska, and Texas. As 
a rule, it is most serious in the more southerly peach-growing sec- 
tions, but during recent years many specimens from farther north 
were sent to the Bureau of Plant Industry for identification and 
for suggestions as to control measures. During the years 1914 and 
1915 the writer found the disease to be serious in the Ozark region of 
Arkansas, being surpassed in destructiveness only by scab and brown- 
rot. 
Note.— This bulletin is of interest to peach growers in the eastern half of the United States and particu- 
larly those of the more southerly parts of this section. It is also of interest to plant pathologists. 
84987°— Bull. 543 17 
