68 U.S. DEPT. OF AGRICULTURE MISC. PUB. 939 





Austrian foresters mistakenly call this fungus "Bnmchorstia pini" 

 according to a paper by Donaubauer (1960). All reports on "Brun- 

 chorstia pint" in Austria actually refer to Cenangium ferrmglnosum. 



This disease is very dangerous for Pirrns nigra and P. sylvestris and 

 it is expected that it will also spread to other pine trees. The damage 

 it caused in Austria was 15,000 fm. (or 4.5 million Austrian schillings) 

 in 1948. 



Control measures. — To prevent this disease from spreading, the 

 diseased trees are felled and the infected branches burned. 



Range : Europe, America. 

 Hosts : Pine trees — 



Pinus attemmta 



P. contorta 



P. nigra 



P. rigida 



P. sylvestris 



P. strohus 

 Literature : 



Donaubauer, E. Die Kieferntriebsterben-Kalamitat 1959/60. A.11- 



gemeine Forstzeitung, 71, Jg., Folge 9/10. 1960. (Informa- 



tionsdienst, 32. Folge) . 

 Spaulding, P. Diseases of North American forest trees planted 



abroad. Agr. Handb. 100, U.S. Dept. Agr. 1956. 



Poplar Canker 



Chondroplea populea (Sacc.) Kleb. (German term: Pappelrinden- 

 tod, Paopelrindenbrand.) This serious disease of poplar has caused 

 heavy damage in Austria — especially in Lower Austria — during the 

 last few years and is, unfortunately, always erroneously termed "Doth- 

 ichiza populea Sacc. & Briard" in phytopathological literature on 

 forestry. 



The disease is found in the crown of old trees and from there it 

 attacks more recent plantations. Very much endangered are afforesta- 

 tions overgrown with weeds (Solidago canadensis). The general 

 opinion now is that the infection attacks the pits or wounds in the bark. 

 It kills the bark and the cambium. Macroscopically such places are 

 detected by distinct indentations in the bark. According to the size 

 of the part infected and the amount of cambial area destroyed, the 

 plant dies off sooner or later. 



Butin (1957) holds the view that the further away the cortical cells 

 are from water saturation, the more quickly the fungus spreads in 

 the cortical tissue. In addition he considers that mild winters further 

 this disease, since the fungus can go on growing while the plant is 

 unable to produce any defensive reactions during hibernation. 



In spring and summer, pycnidia break out through the infected 

 bark and empty the spores in the shape of cirri. The diameter of the 

 pycnidia varies from between 500/* to 1000/a. The hyaline spores are 

 10 to 13ju Ions:, 7 to 9(i broad, and stand on a single base. 



Control Measures. — According to research carried out in Austria 

 it has been found that when afforesting with poplars it is advisable 

 to have a rotation of, for instance, maize, turnips, cabbage, or pota- 

 toes in between. This cultivates the soil and checks the growth of 

 weeds. At the same time it reduces the humidity of the air and checks 

 the germination of spores. Control measures by means of recently 



