UNITED STATES DEPARTMENT OF AGRICULTURE 

 BULLETIN No. 1118 



Washington, D. C. PROFESSIONAL PAPER 



January 26, 1923 



CITRUS SCAB : 

 ITS CAUSE AND CONTROL 



By 



JOHN R. WINSTON, Pathologist 

 OflSce of Fruit-Disease Investigations, Bureau of Plant Industry 



CONTENTS 



Economic Importance and Distribution of 



atrosScab 1 



Species and Varieties Attacked 3 



Description of the Disease 3 



Review of the Literature 5 



The Causal Organism 8 



Pathological Anatomy 12 



Dissemination of the Causal Fungus ... 12 



Conditions Influendnc Infection 13 



Page 



Growth Habits of Grapefruit 20 



Disease as Influenced by the Stock ... 21 



Adaptation of the Fungus 21 



Inoculation Experiments 22 



Spraying Experiments 27 



Commercial Control 30 



Summary 34 



Literature Cited 37 



WASHINGTON 



CM>VERNHENT PRINTING OFFICE 



192S 



