Spraying 



219 



PLUM ENEMIES 



Plums have many enemies but fortunately they 

 can all be effectively checked. First is the curculio, 

 to be treated as described above. 



For leaf-blight — spotting and dropping off of the 

 leaves about midsummer — spray with Bordeaux 

 within a week or so after the falling of the blos- 

 soms. This treatment will also help to prevent 

 fruit-rot. In addition to the spraying, however, 

 thin out the fruit so that it does not hang thickly 

 enough for the plums to come in contact with each 

 other. 



In a well kept and well sprayed orchard black-knot 

 is not at all likely to appear. It is very manifest 

 wherever it starts, causing ugly, black, distorted 

 knarls, at first on the smaller limbs. Remove and 

 burn immediately, and keep a sharp watch for more. 

 As this disease is supposed to be carried by the 

 wind, see to it that no careless neighbor is supplying 

 you with the germs. 



As will have been seen from the above, spraying 

 poisons are of two kinds : those that work by con- 

 tact, which must be used for most sucking insects, 

 and germs and fungous diseases; and those that 

 poison internally, used for leaf-eating insects. Of 

 the former sort, Bordeaux mixture is the standard, 

 although within the last few years it has been to a 

 considerable extent replaced by lime-sulphur mix- 



