468 



Journal of Agricultural Research 



Vol. X, No. 9 



for oat stemrust can be very rarely and weakly infected. On these 

 hosts the uredinia were always very minute and often surrounded by 

 an extremely small dead area. 



There seem to be no marked differences in the rust on different hosts 

 or in dififerent parts of the upper Mississippi Valley and the northern 

 Great Plains area. There appeared sometimes to be differences in 

 virulence, but these were neither very constant nor very distinct. Rust 

 on wheat kindly sent by Dr. F. Stoward from Leederville, "West Aus- 

 tralia, also behaved exactly like common P. graminis tritici. West of 

 the Rocky Mountains, on the other hand, the rust on club wheat and 

 grasses susceptible to P. graminis tritici is quite different, as previously 

 noted. 



Table XXIX. — Results of inoculations with urediniospores of P. graminis tritici 



compacti 



Original host. 



Immediate host. 



Plant inoculated. 



Trials. 



Re- 

 sult. 



Degree of in- 

 fection. 



Triiicunt compactum. 



Do 



Do 



Do 



Do 



Do 



Do 



Do 



Elymus glaucus 



Do 



Trittcum compactum. 



Do 



Elymus glaucus 



Trtticum. ccympactum. 



Do 



Elymus glaucus 



Do 



Triiicum compactum. . 



Elymus glaucus 



Triiicum compactum.. 



Trittcum compactum. 



do 



do 



do 



do 



Hordeum vulgare .... 



do 



Trittcum compactum. 



Hordeum vulgare 



....do 



Trittcum compactum.. 



....do 



Hordeum vulgare 



Triiicum compaciutn. 



....do 



Hordeum. vulgare 



....do 



Trittcum compactum. . 



Hordeum vulgare 



....do 



Agropyron cristatum,. . 

 Agropyron desertorum 

 Agropyron elnngatum . 

 A gropyron imbricatum, . . 

 Agropyron intermedium,. 



Agropyron re pens 



A gropyron ienerum. 



do 



Agrostis alba 



Agropyron siolonifera . . . 



....do 



Alopecurus geniculaius . 



Alopecurus praiensis 



do 



Anthoxanthum odoratum 



do 



Avena saliva 



....do 



....do 



Bromus tectorum .... 



Moderate. 

 Weak. 



Do. 

 Do. 

 Do. 

 Moderate. 

 Do. 



Weak. 



