RATIONAL FRUIT CULTURE. 



77 



little can be done except to prevent infection of healthy trees. 

 Black cords of mycelium travel in the ground for great dis- 

 tances in all directions, penetrating the bark of any tree they 

 reach. To stop them, a trench, eight inches deep, should be 



Fig. 27 The Toadstools which Cause Tree-root Rot. 



dug round any infected tree, well beyond the spread of the 

 branches. All the toadstools should be collected and burned, 

 and as spores are another source of infection, any wounds 

 should be dressed with tar. 



