Page:Popular Science Monthly Volume 43.djvu/91

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81
DECAY IN THE APPLE BARREL.

absent, the skin is unbroken except in a peculiar, almost regular manner. There is an evident central point where the fungus started, and, as it has spread, numerous pimples have formed just under the skin, and sometimes in eccentric circles. From these minute light-colored pimples spores ooze out and are ready to find their way to some other specimen. The affected portion of the apple has a bitter taste, and, on account of this, the term "bitter rot" has long been given to this form of decay. This

PSM V43 D091 Apple bitter rot.jpg
Fig. 5.—Apple Bitter Rot.

same fungus causes the rotting of the grapes, and, if all the facts were known, this Glœosporium fructigenum, Berk., might be definitely charged with a large percentage of the decay of other fruits. An apple badly affected with the bitter rot is shown in Fig. 5, but one regrets that many of the details are lost in the photo-engraving process by which the engraving was made.

This form of rot while it may be met with upon the tree or in the windfalls beneath it in late summer, is most abundant in the storeroom and is decidedly contagious—that is, an apple that is decaying with the bitter rot is able to communicate the decay to other fruits by means of the myriads of spores which are borne upon the surface of the ruptured pimples. These facts suggest the precaution of discarding any rotting fruits whenever found. There is little room for doubt that were the harvested fruits themselves sprayed with a fungicide, it would aid materially in preserving them. Thus, if a thin coating of the Bordeaux mixture was applied, the spores of bitter rot and other decay germs would not so readily germinate. But there is the