Diseases of the Plum 319 



before the fungus becomes established within the tis- 

 sues of the plant. The best treatment, in fact, is to 

 spray very thoroughly with strong bordeaux mixture 

 or pure blue vitriol solution early in the spring, just 

 before the buds start. These two points are to be in- 

 sisted on, thorough early spraying with a strong so- 

 lution. The mixture can be much stronger than that 

 used in summer, for at the time of this spraying there 

 are no leaves out and consequently there is no danger 

 of damage to foliage. 



Toward the close of the blossoming season the 

 trees should be carefully examined. If there are dead, 

 dying and discolored flowers, blackened fruit spurs, 

 spots of gummosis and other indications of the work 

 of the monilia, another spraying is necessary. 



In general it may be said that two or three spray- 

 ings with bordeaux mixture are necessary in dealing 

 with this disease. Two should be given in any case, as 

 directed above, and three should be given if the dis- 

 ease is especially threatening. Inasmuch as these 

 three, or more, sprayings give equal opportunity for 

 combating several other fungous pests and certain in- 

 sect enemies, the plum grower has the greater reason 

 to be prompt and thorough. 



It should be noted here, though it is mentioned 

 elsewhere, that bordeaux mixture used on plum trees 

 after they are in leaf must be weaker than that usually 

 rcommended for apple trees. Damage from strong 

 bordeaux mixture is especially apt to occur on Japan- 

 ese plums. 



When for lack of spraying, or in spite of spray- 

 ing, the disease runs its course, the visible evidences of 

 it remain in blackened twigs and rotted fruit. The 

 fruits which fall to the ground rot or dry there, while 

 the fungus which has killed them matures innumerable 

 spores for the perpetuation of the species. Frequently 



