APPLE DISEASES 



25 



and about ten years later the name bitter-pit was given it in 

 that country. In the early nineties it caused alarm among 

 Australian growers because of its obscure and mysterious 

 nature, and finally an extensive investigation was initiated as a 

 result of action on 

 the part of the 

 growers. First 

 authoritative rec- 

 ords of stippen in 

 the United States 

 date back to 1891 ; 

 it was then com- 

 mon on Baldwins 

 in Vermont. Sub- 

 sequently it was 

 found to occur in 

 Canada, England, 

 France, Russia, 

 South Africa and 

 New Zealand. In 

 fact the geograph- 

 ical range of bitter- 

 pit seems to be 



coincident with that of the cultivated apple. Most damage 

 is done in America and Australia. 



Symptoms. 



The fruit only is affected by stippen. The disease may be 

 found toward the end of the growing-season, at least after the 

 fruit is half grown ; or it may not be seen until after the fruit 

 has been placed in storage. Fruits approaching maturity 

 seem to be in the most critical stage of their development so 

 far as bitter-pit is concerned. Its appearance amongst the 

 fruit on a tree is very erratic. Sometimes only one apple on a 

 twig is affected. Again, all the fruits of a cluster are pitted. 



FIG. 7. Stippen, or bitter-pit. 



