814 



Journal of Agricultural Research 



Vol. VI, No. zr 



Seed Laboratory, and was selected from seed trade samples. The Cor- 

 nell and Minnesota selections or strains were obtained from the Section 

 of Plant Breeding, Division of Agronomy and Farm Management, Min- 

 nesota Experiment Station. A summary of the results of inoculations 

 is given in Table I. 



Table I. — Results of inoculations with Puccinia graminis on Phleum pratense 



It will thus be seen that successful infection resulted in 14 of the 22 

 trials with P. graminis avenae and it occurred on at least 11 different 

 selected strains which when grown in the greenhouse varied consid- 

 erably in type and vigor. Unpublished results obtained by Mr. M. N. 

 Levine, a graduate student in the University of Minnesota, corroborate 

 the work done by the writers. Mr. Levine's inoculations were made 

 with another strain of P. graminis avenae, and, although there is prob- 

 ably little or no difference between one strain of this rust and another, 

 it is interesting to know that the results obtained are not due to the 

 peculiarities of the particular rust strain used. Inoculations on oats 

 with the spores produced on timothy resulted in the formation of typical 

 pustules in about eight days. None of the 774 timothy leaves inoculated 

 with P. graminis tritici produced pustules, and none of the 454 inoculated 

 with P. graminis secalis became infected, although the writers are not 

 convinced that these transfers are impossible. 



