A LITTLE-KNOWN VETCH DISEASE. 



By Frederick A. Wolf. 



Plates 2-6 



Introduction 



In the spring of 1918, a diseased condition of vetcli was noted to 

 be quite abundantly present upon the several species growing- in the 

 vicinity of West Raleigh, N. C, and in the following season, it was 

 so destructive to hairy vetch, Vicia villosa, that the plants were practi- 

 cally all killed before they had reached the flowering stage. Since 

 hairy vetch is the species most widely grown within the State as a 

 winter cover crop and as a feed crop to be utilized either for grazing or 

 for hay, this disease is to be regarded as of considerable economic im- 

 portance. All parts of the plant above ground were affected in a 

 manner quite characteristically different from any of the several dis- 

 eases which had previously' come under the writer's observation. It 

 soon became apparent, from microscopic examination, however, that 

 the disease was identical with one which had first been collected in the 

 summer of 1907 on the horticultural grounds of Cornell Universit}-, 

 Ithaca, N. Y. Since two concise mycological notes^ containing brief 

 descriptions of the appearance of the disease and of the structure 

 of the casual organism, comprise the only publications dealing with 

 this malady, investigations were forthwith begun. It is the present 

 purpose, therefore, to report upon these studies, which have been 

 conducted during the past three seasons, as a contribution to our 

 knowledge of the distribution, symptomatology and dissemination of 

 this disease and of the life history and structure of the pathogen. 



Distribution 



It has thus far not been possible to secure any considerable body 

 of data on the distribution of the disease either within the State or 

 within other States where species of vetch are cultivated. It has been 

 collected in North Carolina, however, within the counties of Forsythe, 

 Rowan, Montgomery, Granville, Wayne, and Wake and has been 

 observed^ by Mr. Roland McKee, Bureau of Plant Industry, Office of 



1 Atkinson, G. F., and Egerton, O. W. Protocoronospora, a new genus of fungi. Jour. 

 Mycol. 13; p. 185-186, 1907. Preliminary note on a new disease of the cultivated 

 vetch. Sci. N. S. 26; No. 664, p. 385-386, 1907. 



2 From a letter to the writer, dated May 23, 1919. 



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