i 



APPLE DISEASES. 191 



In connection with the statement that Corynciim foliicolum 

 is a parasite it is of interest to compare the parasitism of two 

 other species of Coryneum which are of great economic impor- 

 tance. C. beyerinckii Oudem. has been reported by a great 

 many investigators in widely separated places as causing dis- 

 eases of stone fruits. Recently, Smith (5) has made a careful 

 study of "Peach Blight" in California and shows that the dis- 

 ease is caused by this fungus which attacks both the leaves and 

 twigs. The mycelium of the fungus is able to penetrate the 

 bark of new shoots and kills small areas, causing spots. Spores 

 lying about the bud scales produce mycelium which penetrates 

 and kills outright both the bud and the surrounding bark, the 

 spot extending from one-fourth to one inch in length. 



Butler ( I ) gives an account of a disease of the mulberry in 

 India caused by Coryneum iiiori Nom. This parasite attacks 

 young trees in the nursery and the smaller branches of full 

 grown trees. It enters through injured places in the bark but 

 is not able to penetrate the uninjured bark. The treatment 

 recommended for this disease is to avoid the making of 

 unnecessary wounds, to prune in such a way as to make wounds 

 which will heal over readily, and to burn dead and diseased 

 wood after it has been removed. 



Coryneum foliicolnm agrees quite closel}- with Coryneum 

 iiiori in the manner of its attack on the host. In the inocula- 

 tions for leaf-spot, where large numbers of spores were sprayed 

 upon the young branches, no case was observed in which the 

 fungus penetrated the bark and caused disease, therefore it 

 seems probable that the fungus is able to enter only through 

 wounds. The control of such a disease caused by a wound 

 parasite should not be a difficult matter. The same methods 

 carefully applied would also go far toward controlling diseases 

 caused by certain other fungi. All dead and diseased wood 

 should be removed and burned, as this would destroy to a large 

 extent the material for infection. Care should always be taken 

 to avoid unnecessary wounds or wounds which will not readily 

 heal over. 



In connection with a study of apple decays, the writer has 

 isolated fungi from a large number of decaying apples both by 

 the poured plate method and by taking out material from 

 decaying apples from regions which were either some distance 



