54 



PROTECTION OF PLANTS —1924-25 



Foinis I and II are identical in their infection capacities on the variesties 

 in Table III, and Form III differs slightly on two varieties only, with VIII 

 differing on three. Form IV is strikingly different indeed, as practically 

 every variety is susceptible to it. The only two varieties resistant to this 

 culture are Well's Red Kidney and Improved Yellow Eye. 



Table IV shows the degree of infection obtained on Leach's differential 

 hosts. The beans w^ere all planted the same afternoon and the seedlings were 

 were inoculated at the same time under uniform conditions. 



TABLE IV 

 Infection obtained on Leacbs' diflferential hosts with fifteen culture. 



VARIETY 



INOCULATED 



Form. 



Culture No. 



4 6 31 32 33 



II 



2 5 25 26 35 



VIII 



1 16 29 30 23 



Brown ttwedish .... 



Navy 



Red Kidney 



Red Indian 



Navy 



Ruby Hort. Bush . . 

 Improved Yellow Eye 



Minn. 132. 

 Minn 69 . . 

 Minn. 156. 

 Mi n. 1101 

 Minn. 1083 

 Minn. 98 . . 

 Minn. 1096 



CS 

 SR 

 CS 

 CS 

 VR 

 CS 

 CS 



CS 

 SR 

 CS 



s 



R 



CS 



s 



CS 

 CS 

 CS 

 CS 

 VR 

 CS 

 CS 



CS 

 SR 



CS 

 CS 

 VR 



CS 

 CS 



CS 

 CS 

 CS 

 CS 

 VR 

 CS 

 CS 



CS 

 SR 

 CS 

 R 

 VR 

 CS 

 CS 



CS 



s 



CS 



R 



R 



CS 



CS 



CS 

 CS 

 CS 

 R 

 VR 



CS 

 CS 

 CS 

 R 

 VR 



CS CS 

 CS CS 



CS 

 SR 



CS 

 R 

 VR 



CS 



CS 



CS 



R 



CS 



R 



CS 



CS 



s 



CS 

 R 



CS 

 R 

 CS 

 CS 

 CS 



CS 

 VR 

 CS 

 R 

 CS 

 CS 

 SR 



CS 

 VR 



CS 



CS 

 CS 

 CS 



OS 

 R 



CS 

 R 



CS 

 CS 

 VR 



Of the seven varieties inoculated, three showed extreme susceptibility to 

 all of the cultures used, and one was uniformly resistant. Red Indian, Minn. 

 1101 which is used to separate Form I gave a very peculiar reaction to the va- 

 rious cultures. Those marked CS were very badly infected and died, but the 

 lesions were not typical of the usual CS type of infection. They were super- 

 ficial in appearance and did not kill so, quickly. 



Leach's dichotomous key (6) was used to separate the various cultures into 

 the following groups: Form I:— 4, 6, 31, 32, and 33. Form II:— 2, 5, 25, 26, 

 and 35. Form ^TII: -1, 16, 29, and 30. Culture 23 also comes in Form VIII 

 but Improved Yellow Eye, Minn. 1096 is verv resistant to it. Apparantly it 

 does not fit in with Form VII for Ruby Horticultural Bush, Minn. 98 is com- 

 pletely susceptible. 



A close inspection of these three groups, made by using the key, shows that 

 they can still be split into other groups. Thus under Form I we ha\'e 31 and 

 33 similar, and 4, 6, and 32 forming another set. Under Form II, 2 and 35 go 

 together, while 5, 25, 26 constitute a group with similar reactions. Form VIII 

 is not so clear Imt 16 and 30 are closely similar while 1 and 29 are individuals. 



A comparison of all three infection tables would seem to show the following 

 facts:— It is impossible to distinguish I and II from the majority of the cultures 

 isolated here during the course of the work, on the Quebec varieties of beans 



