DISEASES OF SPECIAL CROPS 



99 



turn yellow or wilt and black mycelial strands are found 

 in abundance attached to the roots. Later, groups of 

 sporophores are found about the base of the tree. These 



Fig. 41. — Sprayed apple trees from the same orchard. After Scott and Rorer. 



in general resemble the sporophores of Armillaria. See 

 page 425. 



The isolation of diseased trees by trenching may pre- 

 vent the infection of other trees. Orchards should not be 

 located in soil containing old oak stumps. All infected 

 material should be burned. 



Combination Tkeatment for Apple Diseases 



The following treatment is designed to meet all of the 

 fungous enemies of the apple. In event certain diseases 



