THE PHILIPPINE 
JOURNAL OF SCIENCE 
VOL. 19 AUGUST, 1921 No, 2 
CITRUS-CANKER CONTROL: A PROGRESS REPORT 
OF EXPERIMENTS 
By H. ATHERTON LEE? 
Mycologist, Bureau of Science, Manila? 
TWO PLATES 
INTRODUCTION 
Field investigations on citrus canker in the continental United 
States have been impossible in the past because of the regula- 
tions which have been promulgated to make eradication work 
possible. For this reason, investigations on citrus-canker con- 
trol were undertaken in the Philippine Islands in the summer 
of 1917. The primary purpose of these experiments was to 
determine whether citrus canker could be controlled by means 
Other than total eradication; that is, by the use of fungicides 
and cultural methods. It was believed that, even though 
such control methods should not prove successful, methods and 
ideas might arise which would be of value in aiding citrus-canker 
eradication in the southern United States. 
*The writer wishes to express appreciation to Col. Adriano Hernandez, 
director, and Mr. §S. Apostol, chief of the plant industry division of the 
Philippine Bureau of Agriculture, for the great assistance and the many 
facilities afforded him. It is to them that thanks are due for the use of 
the citrus collection at Lamao, Philippine Islands. Similar deep appre- 
ciation is expressed to Prof. C. F. Baker, dean of the College of Agriculture, 
University of the Philippines, for the use of the citrus collection at Los 
Bafios during these experiments and for assistance in many other ways. 
Thanks are also due to Father M. Selga, of the Weather Bureau, for very 
kindly assistance in supplying climatological data. 
: The work was begun while the writer was under the direction of the 
United States Department of Agriculture, and credit is due to that insti- 
tution for the inauguration of this work. 
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