254 STATE HORTICULTURAL SOCIETY. 



new spores. Where the cuticle upon youngs apples is first ruptured, 

 very small rusty or olive green spots are first noticed. These, if cli- 

 matic conditions remain favorable, continue to grow. The spots grow 

 larger, but as they grow larger the fungus often dies out in the center 

 of the spots, but growth always remains active around the edges. It 

 spreads a good deal like the skin disease known in the human family 

 as ringworm. Often two or more of those spots run together, and 

 these form blotches. If conditions are favorable, the spots remain 

 active until the apples are finally used up, whether that be in the fall 

 or spring following. Though, if on the other hand the weather during 

 the season is dry and warm, the fungus will quit growing; it will, how- 

 ever, renew its growth whenever conditions become favorable. 



This is, in short, the life history of the parasite known as apple 

 scab. I did not, however, describe the fungus as it grows upon the 

 leaves and young shoots, fearing that I would get my paper too long. 

 This, however, does not matter much, as the conditions are very much 

 the same. 



WHAT TO DO FOR APPLE SCAB. 



Spraying with fungicides to prevent the germination of the spores 

 is one of the principal remedies, yet it has one most serious drawback, 

 for a season most favorable for the germination, the spores and the 

 tlourishing of the parasite, is at the same time the most unfavorable 

 for spraying. These relations will undoubtedly always exist, for I see 

 no way to overcome them. Therefore we can't depend upon spraying 

 alone, but must in addition try to find some other way to work against 

 the ravages of the apple scab. 



As shown before, the spores live over winter in dead leaves and 

 infected apples. Here is certainly one period in the life-history of the 

 parasite where we can do some valuable work. We must try to destroy 

 all the spores possible. In small orchards the leaves might be col- 

 lected and burned, though in large ones this would not be practicable. 

 The infected apples, however, can be collected and destroyed. This 

 latter part should be well done. I doubt very much whether the 

 spores can be destroyed by turning sheep and hogs into the orchard. 

 I am rather inclined to think that they will go through an animal un- 

 harmed. Quite recently, while enjoying the hospitalities of friend S. 

 Miller, our conversation drifted onto this subject. Mr. Miller seemed 

 to be positive that the spores would all be killed in passing through a 

 hog or sheep. I had no positive proof that he was wrong. At the 

 same time I could not see that he could back up his opinion by posi- 

 tive proof. The only way that this point can be settled is by culture 



