INSECTS AND DISEASES 



spot Is also frequently serious In some seasons 

 and localities. 



(i) The Apple Scab, commonly known 

 among growers as " the fungus," Is the most 

 important of our common apple diseases and 

 is most evident on the fruit, although It attacks 

 the leaves as well. In some seasons the fruit is 

 made almost unsalable. This disease lives 

 through the winter on old leaves. In the spring 

 about blossoming time the spores are scattered 

 by the wind and other agencies, and reaching 

 the tender shoots germinate and enter the tisses 

 of the plant. Their development Is greatly 

 dependent on the weather. In a season In which 

 there is little fog or continued damp or humid 

 weather, they may not develop at all, but 

 where these conditions are present they fre- 

 quently become very virulent. 



Spraying will be governed by the weather 

 conditions, but the mixture must be applied very 

 promptly as soon as it is evident that It Is likely 

 to be necessary and must cover every part of 

 the tree to be effective. The object Is to prevent 

 the spores from germinating, the spray being 

 entirely a preventive and In no sense a cure. 

 The disease most frequently first manifests It- 

 self on the tender new growth and on the blos- 

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