MICHIGAN ACADEMY OF SCIENCE. 183 



THE EFFF.CT OF FUNGICIDE ON THE SPOKE (JERMINA- 

 TION OF LOKGYEAirS AETEKXARIA. 



RY R. AV. OOSS AXn S. P. DOOLITTLE. 



Histori/. It is a coiiiinon oceniTenee to find ajipaivntly sound 

 apiiles liaviiifi' a core cavity filled with a dark, «>TaYisli mold. 



For the most part, this condition received little attention from 

 mycologists and pathologists until 1902. when Prof. W. Paddock, 

 at the Coloiado Experiment Station, noted the disease as extensive 

 in both Colorado and California. 



In 1903, B. O Longyear. at the Michigan Experiment Station, 

 noted the same core decay and considered it to be of widespread 

 occurrence. He made his first reference to the disease in the 

 Colorado Experiment Station Report for 1904. In 190."), he ])ub- 

 lished a bulletin on the disease, in which he refers to his own and 

 Paddock's observations.* Longyear in this publication, describes the 

 conditions of fungous attack, the geographic distribution of the 

 disease and the susceptible varieties. The fungus was an Alter- 

 naria and a brief description was given. It Avas not given a specific 

 name, and since that time it has been referred to in literature on 

 the subject as Longyear's Alternaria. . Longyear })roved the patho- 

 genicity of the fungus, both at the Michigan Station and at 

 Colorado. 



The material used for the following work was obtained from 

 specimens sent in from an orchard in South Haven and was com- 

 pared with herbarium sjtecimens collected by Locav at Michigan 

 Agricultural College in 190:}, (later examined by U. 0'. Longyear.) 

 Fresh material was also compared with specimeus obtained from 

 Longyear in Colorado. 



From the symptoms on the fruit and from the microscopic charac- 

 ter-istics these specimens appeared to be identical. The cultural 

 characteristics also apj>eared identical with the results j)ublished 

 by Tx)ngyear in Colorado. 



Distrihiition. The disease is found over a wide range of territory 

 and investigation shows it to be of common occurrence in tlie fruit 

 districts of Colorado and California. It has been found by the 

 writers in Michigan and has Ijeen mentioned as appearing in Maine. 



♦Longyear, B. O. Col. Sta. Bui. 105. 



