B. r. 1.-072. 



TIMOTHY RUST IN THE UNITED STATES. 



DISTRIBUTION OF THE RUST OF TIMOTHY. 



Rust of timoth}^ was reported in this country by Trelease as 

 early as 1882/ Farlow and Seymour, on the basis of this report, 

 mentioned Puccinia graminis on Phleum pratense L. from the United 

 States in their " Host Index of the Fungi of the United States" (1888). 

 Rust of timothy was reported as causing considerable damage in the 

 experimental plats at the Iowa experiment station in 1891.^ From 

 1891 to 1906 the parasite seems to have been little in evidence 

 throughout the country, and the writer has been unable to find any 

 mention of it during those years. 



In 1906 the rust became epidemic in the experimental plats at the 

 Arlington Experimental Farm. In 1907 it was epidemic at points in 

 New York and Virginia; it was also reported from Delaware, West 

 Virginia, and Ontario, Canada. In 1908 this rust was widespread 

 and caused much damage in New York, Pennsylvania, Delaware, 

 Maryland, and Virginia; it was also reported from West Virginia, 

 Ohio, Michigan, Wisconsin, and Minnesota. In 1909 the rust was 

 common in many of the States mentioned and in addition was 

 reported from Indiana, Kentucky, Iowa, and Maine. In 1910 it was 

 observed in many vStates from which it had been previously reported, 

 and in considerable quantity in Virginia, New York, Michigan, and 

 Minnesota. In the last State it was collected at both New Richland 

 and Owatonna, and in August was exceedingly abundant in timothy- 

 pastures around Crookston. Thus, from being only locally observed 

 in 1906, this rust was widespread in 1909 and 1910, having been 

 reported from Maine to Ontario and northern Minnesota, and south to 

 Iowa, Kentucky, and Virginia.^ 



> Trelease, William. Parasitic Fungi of Wisconsin. Transactions of the Wisconsin Academy of Sciences, 

 18S2, p. 131. A specimen collected in Wisconsin was kindly sent to us for examination by Dr. Trelease 

 from the Missouri liotanical Gardens. It was rather unsatisfactory, as it consisted of only one rusted 

 leaf, and thus may have been inaccurately determined, leaving some doubt as to the authenticity of this 

 early report. 



s Wilson, J., Curtis, C. F.,and Kent, D. A. Time of Sowing Grass Seed. Bulletin 15, Iowa Agricultural 

 Experiment Station, 1891, pji. 285-280. 



3 The writer is indebted to botanists and plant pathologists at the various agricultural experiment sta- 

 tions and to J. J. Davis, M. W. Evans, E. M. Freeman, R. A. Harper, Frank D. Kern, W. J. Morse, C. V. 

 Piper, H. N. Vinall, H. J. Webber, and others who have answered letters of inquiry in regard to the rust 

 on timothy or have given information as to its prevalence in various localities. 



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