XXXIII 



Diseases of the Plum 



LUM trees and fruit are subject to 

 several diseases, of which only 

 a few are of special seriousness. 

 The worst ones are ripe rot 

 (monilia) and black knot. 

 These vary greatly in virulence 

 according to season, weather, 

 locality and varieties. Reason- 

 able care will prevent serious 

 damage by any of them. 



Ripe rot (Monilia fructigcna). — This is a fungous 

 disease which shows most conspicuously in the rotting 

 of the fruit at ripening time or just before; but it also 

 attacks the twigs and young growth of the trees, do- 

 ing equal or greater damage there. When this rot 

 occurs on ripening fruit, the skin turns black or brown 

 and is finally covered, partially or wholly, by small 

 pustules or little bunches of spores, somewhat smaller 

 than the head of a pin. 



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