APPLE DISEASES 123 
portions on the branches suffer most because they are exposed 
to extremes of temperature. Likewise apples on the south or 
southwest sides of trees are always most affected. (3) Defolia- 
tion or reduced foliage-area. Should a tree be defoliated by 
some pathogene or other cause shortly before the ripening-period, 
the fruit is likely to suffer from water-core. The decrease in the 
foliage-area results in reduction of the evaporating surface, 
consequently an excess of water is liable to accumulate. Severe 
pruning may also act detrimentally in this way. The removal 
of a large number of branches means the reduction in the num- 
ber of leaves, and therefore checked transpiration. Any injury 
to the foliage, but which at the same time does not cause de- 
foliation, tends to have the same effect with respect to water- 
core. (4) Excess tension set up in the cell as a result of a rapid 
ripening process. In ripening, the starch is converted into 
sugar; water is absorbed by the sugar and there results a high 
pressure tending to force water into the intercellular spaces. 
Control of water-core. 
It seems to be out of the question to whally prevent water- 
core, since certain climatological factors are so intimately in- 
volved. Some authorities say that it is absent where the soil is 
well managed throughout the year; that it is absent in soil of a 
loose texture ; and that adequately drained soil seldom produces 
-glassiness in fruit. Further observations along these lines are 
necessary before positive conclusions can be reached. The 
conditions already enumerated under which water-core has 
been observed may offer some suggestions as to remedial meas- 
ures, although prevention or cure are as yet little short of 
impossible. Among those recommendations worthy of note 
are: — (1) In thinning the crop those fruits nearest the tip of 
the branches should be removed, especially in cases where pref- 
erence is not otherwise to be shown. (2) Cultivation should 
proceed normally, and a cover-crop should be planted at least 
as early as the middle of July to remove excess moisture. 
