BLISTER RUST RESISTANCE OF WHITE PINES IN EUROPE 



235 



YEARS 



10 

 YEARS 



12 3 4 5 



1 



12 3 4 5 



15 

 YEARS 



16 



12 3 4 5 



12 3 4 5 

 INFECTION CLASS 



12 3 4 5 



Figure 1. Degrees of infection of seedlings of Pinus strobus 

 at various ages by Cronartium. ribicola: seed collection S. 867-45. 

 Infection classes: l--healthy (not infected), 2--healthy 

 (previous infections were defeated), 3--branch infection only, 

 4--stem infections, 5--dead. 



YEARS 



12 3 4 5 



1 '° 

 J YEARS 



L_ib 



YEARS 



12 3 4 5 



J 



12 3 4 5 

 INFECTION CLASS 



2 3 4 5 



16 



YEARS lj 

 > 



12 3 4 5 



Figure 2. Degrees of infection of seedlings of Pinus strobus 

 at various ages by Cronartium ribicola: seed collection S. 863-45. 

 Infection classes: l--healthy (not infected), 2--healthy (previous 

 infections were defeated), 3--branch infection only, 4--stem 

 infections, 5--dead. 



