Insect and Disease Control 275 



the disease, in Rolfs' experience, but apparently little is 

 to be feared from it in orchards that receive good cultural 

 attention. 



Root-rot 



This term is used in a rather broad sense and is applied 

 to several distinct fungous diseases which attack the roots 

 of peach and other trees, causing them to decay, and result- 

 ing in the death of trees so affected. These diseases all 

 develop under much the same conditions. The loss from 

 them aggregates a large amount in some sections. 



Course of development. 



It often happens that the grower is unaware of serious 

 trouble with any of his trees until he discovers one or several 

 that appear "sick"; the foliage may be wilting; the early 

 death of the tree is perhaps apparent. 



On examination, it may be found that the tree can be 

 tipped over easily and that the roots, save perhaps one or 

 two, are dead and decaying. Or if the tree still stands 

 firmly in its position, it may be that the disease has girdled 

 the trunk at, or just below, the surface of the ground and 

 the bark there is dead. Sometimes, also, a tree dies be- 

 cause the disease has destroyed the power of the roots to 

 function, even though they may not have decayed when 

 the tree dies. Whichever one of the various fungi may be 

 at work, the results are usually the same — the death of 

 the tree. 



Not infrequently there is particularly heavy loss from 

 this t^'pe of disease where an orchard is planted on recently 

 cleared land which contains many decaying roots of forest 

 trees. 



