20 MASSACHUSETTS HORTICTILTIIRAI. SOCIETY. 



I said that the fact of the recent increase of fungous diseases 

 could be at least partially explained, and I trust that I have made 

 the matter as plain to you as it is to me. I further said that such 

 an increase was not beyond our control. Let us then discuss as 

 briefly as possible, how we may in a measure prevent the attacks 

 of parasitic fungi. I say prevent rather than cure, because, as 

 you will remember, the vegetative system of fungi is usually 

 buried in the tissues of the leaves, fruit, or roots affected and is 

 practically out of the reach of fungicides. As a rule all proposed 

 treatment must be preventive rather than curative. 



We recognize two definite lines of treatment of fungous 

 diseases — the one hygienic, aiming to eradicate disease by the 

 alteration of external conditions conducive to its spread ; the 

 other consisting in the application to the parts endangered, of 

 some substance inimical to fungous growth. 



Enough has been said regarding the nature and life-history of 

 fungi, to show you that if we can destroy both the spores and the 

 mycelium of a fungus while those organs are either dormant or 

 have not yet reached maturity, we shall get at the root of the 

 whole matter. Here a little common sense is of great assistance. 

 Fruit rots and falls prematurely, usually because it has been 

 attacked by a parasitic fungus ; the same agency causes leaves to 

 blight and fall from the trees. Such fruit and leaves are allowed 

 to remain where they fall, because they are of no use. But the 

 fungus within their tissues remains protected during the winter, 

 develops slowly, and with the approach of warm weather 

 produces its spores in vast numbers, each spore able to reproduce 

 the fungus upon the budding leaves and young fruit of the tree 

 immediately above it, if a slight breeze should cause it to lodge 

 there. No preventive treatment of any nature in spring or 

 summer will protect completely fruit and leaves so wantonly 

 exposed to disease. If the rotten fruit be not allowed to 

 remain where it falls it is usually fed to the pigs. The spores 

 of the fungus pass uninjured through the alimentary canal of the 

 animals, are voided with the manure, find their way to the com- 

 post heap, and thence are spread broadcast over our fields and 

 orchards ; and again we wonder that our summer treatment of the 

 trees with fungicides is of so little avail. The only reasonable 

 method to pursue is to gather carefully at the time of harvest, and 

 at once burn, all diseased fruit and leaves. 



