APPLE DISEASES “121 
expected to be affected very little in comparison to those which 
are exposed to the sun. The diseased portion of the fruit is not 
easy to detect externally, hence the presence of water-core in 
an apple may not be suspected. However, the experienced 
observer is sometimes able to detect diseased fruits by their 
external appearance. Fruits which should be normally green 
or yellow will show a blush on one side. Red or dark-colored 
apples do not exhibit such marked external signs of the trouble. 
On cutting into a water-cored apple, hard, transparent, watery 
areas are found in the flesh. Such areas are practically always 
in close connection with the vascular system. The first evidences 
of water-core are found here. The bundle shows a water-soaked 
area about it. The lesion may be near the stem or elsewhere in 
the flesh, since the bundles are scattered. Occasionally these 
scattered spots may be small, or there may be extensive watery 
areas near the surface of the fruit, although none extends up to 
the skin. Affected apples give off a sweetish, fermented odor, 
and the taste is not unlike that of frozen fruit. In the later 
stages, liquid is usually found in the seed cavities and the harder 
inner membrane of the carpels is cracked and covered with 
hair-like growths, which eventually assume a brownish aspect. 
Cause. 
The presence of excess water in the affected tissues gives the 
described appearance. But the factors which bring about this 
excess water in certain regions of the fruit are not thoroughly 
understood. It seems certain that fungi, bacteria and insects 
are not concerned in bringing about water-core. It is generally 
accepted that conditions affecting transpiration are the prime 
factors inducing water-core. Reduced transpiration results 
usually in excessive sap-pressure, and water is forced into the 
spaces between the cells of the fruit, giving the affected area a 
glassy, transparent appearance. There is no one factor which 
can bring about water-core; two or more factors are necessary, 
and these must favor excessive sap-pressure and reduced tran- 
