CONTENTS 
Pag-e 
Introduction 5 
Distribution ._ - 5 
History ~ 6 
Symptoms and General Appearance 7 
Description of the Fungus 10 
Conidial Stage _ _ 10 
Ascogenous Stage 11 
Mycelium „ - 12 
Experimental Infection 15 
Ascospore Inoculations 17 
Conidia Inoculations 19 
Infected Wood Inoculations 21 
Pure Culture Inoculations 21 
Root Inoculations 24 
Determination and Identification of Infection 24 
Growth of Mycelium in the Wood 28 
Inoculation in Tissues of Different Ages 28 
Inoculations in Stubs 32 
Inoculations in Trees of Different Ages „ „ 33 
Root Inoculations 33 
Seasonal Susceptibility 35 
Effect of Soil Moisture on Susceptibility 37 
Relation of Available Nutrients to Susceptibility _ 42 
Varietal Susceptibility 46 
Methods of Control _ _ 57 
Methods of Preventing Infection. _ 62 
Conclusions „ 64 
Recommendations _ 66 
Bibliography _ 68 
