114 



AGRICULTURE FOR BEGINNERS 



The Club Root. The club root is a disease of the cab- 

 bage, turnip, cauliflower, etc. Its general effect is shown 

 in the illustration (Fig. 101). Sometimes this disease does 

 great damage. It can be prevented by the use of lime at 

 the rate of from eighty to ninety bushels per acre. 



The Black Knot. The black knot is a serious disease of 

 the plum and cherry tree. It. attacks the branches of the 

 tree and is well illustrated in Fig. 102. Since it is a con- 

 tagious disease, great care should be exercised to destroy 

 all diseased branches of the wild or cultivated plums or 



7 



FIG. 101. CLUB ROOT 



cherries. In many states its destruction is enforced by 

 law. All black knot should be cut out and burned some 

 time before February of each year. This will cost little 

 and save much. 



