172 



DISEASES OF CULTIVATED PLANTS 



near. After the tree is dead, the second or ascigerous form 

 of fruit bursts through the bark in larger pustules than those 

 formed by the conidial fruit. 



In all the cases I have investigated in the field, the common 

 practice of planting too deep had been followed, and this I 

 feel assured has something to do with the disease, more 



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Fig. 43. Eutypella prunastri. 1, portion of stem of young plum-tree show- 

 ing conidial stage of fungus ; 2, portion showing ascigerous stage on the 

 dead bark. 



especially when the soil is inclined to be stiff. Under such 

 circumstances numerous large lenticels are formed on the 

 stem, and I have found by experiment that if spores of the 

 conidial condition of the fungus arc applied to such lenticels 

 during damp weather infection follows. 



To guard against infection from air-borne spores, cover the 

 trunk and branches with a mixture of lime and soft-soap. 

 Diseased trees should be removed and burned. 



