SPECIAL REPORT FOR YEAR. 59 



pears to be of considerable economic importance in Maine, be- 

 ing associated with "silver top" of various grasses. It was 

 isolated from dent, flint, and sweet corn, fowl meadow grass, 

 June grass, quack grass, redtop, timothy and potato tuber. 

 This same fungus has been credited with being the cause of :- 

 decay of carnation buds in Nebraska and New York. In this 

 connection an important fact was discovered. It was found 

 that the strains from June grass, quack grass, redtop and 

 timothy were capable of causing the carnation disease while the 

 remaining strains of the same species did not do this, but so 

 far as discovered were identical with the first mentioned m 

 every other respect. 



The final studies have shown that neither of the species 

 which are commonly associated with decay of apples in Maine 

 are identical with that which produces a similar apple rot of 

 Europe. This work represents the first record of an apple 

 •disease caused by any representative of the genus Fusarium 

 in America. This is somewhat remarkable as all of the strai.is 

 tested were more or less pathogenic to apple fruits, and at 

 least one more in addition to the 2 mentioned produced a rapid 

 and complete decay. 



It is also interesting to note that 5 species of Fusarium 

 were isolated from decaying potatoes and 2 of these are also 

 the cause of apple decay. Numerous other facts of a similar 

 nature were brought out with reference to other, unrelated host 

 plants, all going to show, as has been proven with certain other 

 plant diseases, especially the powdery mildews, that the old 

 notion that a different host means a diiTerent species of the p.'ii- 

 asite is by no means correct. At the same time, as has been 

 pointed out in connection with F. pow strains which to all ap- 

 pearances are of the same species may dififer biologically in 

 their ability to attack a given host. 



