CONTENTS 
Introduction 5 
Economic Importance of the Soy Bean 6 
Other Soy Bean Diseases 7 
History, Occurrence and Importance of the Disease 8 
Symptoms 10 
Etiology 13 
Comparison of the Soy Bean Species of Fusarium with Other Wilt-Pro- 
ducing Species of the Genus 16 
A. Source of Cultures and Methods of Isolation .16 
B. Culture Media and Their Various Effects on Species of 
Fusarium ..18 
C. Methods of Study and Pres:;ntation 19 
D. Results of the Comparison of the Soy Bean Fungus With other 
Members of the Section Elegans 20 
Morphological and Cultural Comparison of the Fusarium Species on Soy 
Bean with F. Tracheiphilum 23 
Inoculation Experiments 25 
Experiments on the Relation of Various Soil Factors to Infection of 
Soy Beans by F. Tracheiphilum 30 
A. The Influence of Soil Types 30 
B. The Influence of Acidity and Alkalinity 33 
C. The Influence of the Nematode {Heterodera Radicicola) ..35 
D. The Influence of Soil Temperature 37 
E. The Influence of Other Organisms ; 38 
Field Experiments to Determine the Susceptibility of Varieties 38 
Summary 41 
Literature Cited 42 
