Chemical Injury 
Apples readily absorb undesirable odors. If stored in the presence of 
any foreign odor the flavor of the fruits will be impaired or even ruined. For 
cleaning the storage rooms, the safest recommendation is to scrub the floors 
and white-wash the walls and ceiling. In cleaning field or storage boxes, steam 
is effective and leaves no odor. 
Very little has been publised about chemical injuries. Ginsburg (61), 
however, reported that browning occurred on fruits that came in contact with 
wood of boxes that had been treated with copper sulfate. He also found that 
treatment of bulk bins with wood preservatives caused tainted fruits. 
Virus Diseases 
About 15 virus diseases affecting the apple are known to occur in apple- 
producing areas of the world. Most of these occur in Europe. 
Atkinson and Robbins (9) reported a virus disease known as green crinkle, 
which affects only the fruits, occurring in all important apple districts of 
New Zealand. 
Since 1945 established virus diseases in the United States, such as 
mosaic and stem pitting, have continued to spread and new virus diseases have 
Certain viruses affect the quality and grade of the fruits. Examples 
are russet ring, star crack, scar skin, and dapple apple. Affected fruits show 
the blemishes at harvest and the condition does not change during storage or 
marketing. 
Physiological Diseases 
Bitter Pit 
Bitter pit, also known as stippen in Germany and as Baldwin spot on that 
variety in the United States, is a physiological disease of certain varieties 
of apples. Bitter pit was first described in Germany in 1829 and is worldwide 
in occurrence, 
Typical bitter pit starts at the calyx end of the apple as relatively 
small, round to angular indentations in the surface. The depressions are 
usually subtended by a small, more or less round mass of dead spongy tissues. 
Sometimes, especially in certain varieties, spongy masses of dead tissues occur 
deeper in the flesh, Often the spongy tissues shrink because of loss of mois- 
ture, and a cavity is formed. Some varieties such as Summer Rambo, Gravenstein, 
and Arkansas, which are highly susceptible to bitter pit, may develop pits 
nearly to the stem end, The surface of the pits may at first be deeper colored 
than normal but upon standing the color changes to grayish brown. The largest 
pits eventually become brown to black. Pits on certain varieties such as Yellow 
Newtown, Winter Banana, and Baldwin are larger than those described above and 
tend to be round with flat bottoms, 
In the United States commercial varieties that are quite susceptible to 
bitter pit are as follows: Summer Rambo, Gravenstein, Baldwin, Northern Spy, 
Grimes Golden, Rhode Island Greening, Delicious, Stayman, Arkansas, and Yellow 
Newtown. York Imperial has at times been listed with susceptible varieties, 
but it is purposely omitted here, At times York develops true bitter pit either 
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