THE BLACK KNOT 55 



not wish to remove, it is believed that painting them 

 with a mixture of red oxide of iron in linseed oil will 

 destroy them. Probably an application of the Bordeaux 

 mixture would prove equally effective. All trees liable 

 to injury by this disease should be examined at frequent 

 intervals, and any signs of forming knots be at once 

 removed. 



Concerted action is necessary among all the fruit 

 growers of a neighborhood, if the disease is to be stamped 

 out. Local horticultural societies should agitate the 

 matter and create a public opinion that will render it 



FIG. 28. PLUMS AFFECTED BY IJROWN ROT. 



uncomfortable for any one to allow the knots to remain 

 on his trees as a source of contamination for his neigh- 

 bors' orchards. In some states laws have been enacted 

 compelling the destruction of the knots. Wild cherry 

 trees should be included in the examination for diseased 

 trees. 



Literature. Dr.^Farlow's article was published 

 about 1875, in the Bulletin of the Bussy Institute. An 



