RUST RESISTANCE OF OAT VARIETIES. 9 



majority of cases all leaves or culms inoculated showed infection 

 (normal uredinia) except in certain varieties where there were very 

 evident signs of resistance and to which attention is directed In the 

 footnotes to Table I. 



Table I. 



-Summary of notes on the rust resistance of oat varieties tested in the 

 greenhouse at Cornell University, Ithaca, N. Y., 1915-16. 



[R.= resistant; S.= susceptible.] 





Identification numbers. 



Crown rust. 



Stem rust. 





Variety. 



§ 

 o 



■a 



| 



03 



in ,2 



03 

 5 



® . 



— i 4-> 



03 03 

 u 

 O 



M 



a 



w 

 to 



a 



« 

 CO 



•6 



03 



~§ 



o3:£ 

 .£2 u> 



03 H 



a 



co 



■e) 



03 

 <D . 



o3£ 

 ™ bo 



c a 



Remarks. 



1 



2 



3 



4 



5 



6 



7 



8 



9 



10 





Common (sativa) varieties: 



7 

 94 



9 

 11 



23 



39 

 51 



42 

 102 

 37 



108 

 29 

 91 



8 

 89 

 33 



96! 

 68' 

 69 



4' 

 2 



104! 

 83 

 46 



103 

 97i 

 41 1 



106 

 98 

 36 



34 

 88 

 43 



79 









272 



S. 

 S. 



s. 

 s. 



s. 

 s. 

 s. 

 s. 

 s. 

 s. 

 s. 

 s. 

 s. 

 s. 

 s. 

 s. 

 s. 

 s. 

 s. 

 s. 

 s. 

 s. 

 s. 

 s. 

 s. 

 s. 

 s. 

 s. 

 s. 

 s. 

 s. 

 s. 

 s. 

 s. 



fi°R. 



l(+s.) 



s. 

 s. 

 s. 

 s. 



s. 

 s. 

 s. 

 s. 

 s. 

 s. 



S. 

 S. 

 S. 



s. 



s. 

 s. 

 s. 

 s. 

 s. 

 s. 

 s. 

 s. 

 s. 

 s. 

 s. 

 s. 

 s. 

 s. 

 s. 

 s. 

 s. 

 s. 

 s. 

 s. 

 s. 

 s. 

 s. 

 s. 

 s. 

 s. 

 s. 

 s. 

 s. 

 s. 



12 s.? 



s. 



is.? 

 s. 

 s. 



s. 

 s. 



2R.? 



s. 

 s. 

 s. 



s. 



s. 



s. 



»s.? 



s. 

 s. 

 s. 

 s. 



sR. + S. 



JR.? 



S. 



S. 



s. 

 s. 

 s. 



8R. + S. 

 S. 

 S. 

 S. 



s. 

 s. 

 s. 

 s. 



J13R. 



( +s. 







1797 















275 

 280 



305 

 348 















Archangel X Early Goth- 

 land 

























206 







Big Four 





354 







1804 















342 







1814 

















s. 

 s. 

 s. 

 s. 

 s. 

 s. 

 s. 

 s. 



*R.? 



«s.? 



s. 

 s. 

 s. 

 s. 

 s. 

 s. 

 s. 

 s. 

 s. 

 s. 

 s. 

 s. 

 s. 



}'iR.+ 







1791 

















273 







1729 

 









Colorado No. 9 







336 







1798 













651 

 672 















Early Champion 



Early Gothland 















26 







1807 











730 









GartonNo.396 





405 







1805 

 1799 













1 











350 



Do. 





1808 

 1800 

























341 



6 



340 

























Pickett 



1728 















391 





Ruakura Rustproof 9 





701 





[ Do. 







i Normal infection on one plant; on the other, only a few uredinia surrounded by purple blotches. 

 2 Only a few abnormally small uredinia in 14 days after inoculation. 



s No uredinia in 10 days after inoculation, and finally only one on each culm, accompanied by purple 

 color of host tissue. 



4 Only a few tiny uredinia on each leaf. 



6 Normal uredinia on one culm; only a few on the other. 



6 Infection only fairly vigorous. 



' Unusually small uredinia first appeared 14 days after inoculation. 



8 Normal infection on one culm; no uredinia on the other. 



9 The results with this variety probably were more interesting and valuable than those from any other 

 included in the test, for there were signs of resistance to both rusts at both stages of growth. This variety 

 is of undoubted value as a source of the character of rust resistance, the more so because of its resemblance 

 to yellow and white oat varieties of the A vena sativa group. 



)0 Six leaves severely rusted; on four only extremely small uredinia. In two pots of seedlings later 

 inoculated no normal infection resulted. 



ii Flecks only; no uredinia. Within two weeks the small dark telia, characteristic of resistant varieties, 

 were formed. 



i 2 Uredinia moderately abundant, somewhat small and surrounded by yellow flecks. 



1 3 On one plant uredinia were abundant and of normal size. On the other plant they were small and 

 tardy in breaking through the epidermis. 



