- 4 - 



peel area of the apple and decreasing bitter pit after harvest is 

 by the use of calcium nitrate sprays before harvest. 



Bitter pit tests in Virginia over the past 10 years are shown 

 in the following table. 



Year 



Check 



% BITTER PIT 



Cal ci urn 

 Nitrate 

 Sprayed 







1, 



7, 



9, 



6, 



0, 



0, 



8, 



Average 



13.1 



4.4 



% 

 Reducti on 



of 

 Bitter Pit 



96 

 94 

 38 

 50 

 45 

 80 

 60 

 50 



66 



Cork Spot 

 To help characterize cork spot, we might look at how cork 

 spot differs from bitter pit in the Virginia area. 



Cork spot develops during the growing season and is always 

 present at harvest time while bitter pit is initiated during the 

 growing season but pitting usually develops after harvest. 



Cork spots are small to large brown spots located near the 



surface or deep in the flesh while bitter pits are small, usually 



just below the surface and mostly present in the blossom end of the 

 apple . 



Cork spots are harder than the surrounding flesh while bitter 

 pits are softer than the flesh. 



Evidence of cork spots start to appear in our area in July 

 but may develop up to harvest. Some severe cork spotted fruits may 

 drop before normal harvest. 



In addition to cork spot of the York variety, at times called 

 York Spot, cork spot has been a problem in some seasons on Red De- 

 licious and to a lesser extent on Golden Delicious and Stayman in 

 our area . 



Cork spot may be virus related but bitter pit is probably not. 



Many of the factors that increase bitter pit also appear to in^ 

 fluence cork spot in a similar manner. 



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