VERTICILLIUM WILT OF ELM 



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Verficillium Wilt. 

 Again, only labora- 

 tory cultures can dis- 

 tinguish this diseose 

 from other elm wilts. 

 Although it may re- 

 cur in later yeors, 

 Verticillium wilt is not 

 considered serious 

 because elms often 

 recover. However, 

 the disease affects 

 many plants other 

 than elms. It often 

 kills maple trees, and 

 has been found in 

 maple twig samples 

 sent to the Shade 

 Tree Laboratories 

 from the towns 

 marked on the map 

 at right. 



-a, ,k 





VERTICILLIUM WILT OF MAPLE 





CYTOSPORA CANKER OF ELM 



Cyiospora Canker. Al- 

 though this disease is 

 not a wilt disease, it 

 may be found when 

 elm twigs are cul- 

 tured for wilts. Small 

 cankers on twigs and 

 branches do not cause 

 the tree to wilt but 

 may spread from 

 one branch to another 

 and cause the tree to 

 die back over a 

 period of yeors. This 

 disease also affects 

 other tree species. 

 It is one of the most 

 common diseases of 

 spruce trees in our 

 state. 



