THE DISEASES OF FRUITS. 217 



Remedies. — From the fact that the fungus comes late in the 

 development of che apple and often grows most rapidly after 

 the fruit is packed, it is evident that the early sprayings recom- 

 mended ii\ the case of the scab will be sufficient. The subject 

 has been extensively studied at the Virginia Experiment 

 Station and from the bulletins therefrom published it is 

 clearly shown that the Bordeaux mixture is an effective rem- 

 edy, but the sprayings need to extend through the season. It 

 seems to be a fact that this fungus is much aided in its en- 

 trance into the fruit by an injury that may have happened to 

 it. A worm hole may provide the open door, or the scab 

 fungus furnishes a place for the lodgment of the spores upon 

 an otherwise smooth impervious skin. In the same manner 

 any bruising, especially if the surface is broken, will give an 

 opportunity for the ripe rot germs to enter. It follows from 

 this that early sprayings that keep off the scab and any in- 

 secticide to keep away destructive insects will indirectly have 

 a good effect. It goes without saying that in the harvest 

 care should be exercised that the fruit is gathered without 

 any rough handling, and of course any specked fruit must be 

 discarded, as the ripe rot propagates rapidly by contact. 



The Black Rot {Sphceropsis malorum Berk) is similar to the 

 ripe rot in coming late in the development of the fruit, but is 

 distinguished from the latter by the great difference in micro- 

 scopic structure, by the dark color of the diseased flesh, and 

 by the production of innumerable pimples of considerable size 

 upon the surface of the affected parts in which the brown 

 spores are borne. 



Remedies.— Th.er& is nothing under this head to add to that 

 given for ripe rot, with which this fungus is often closely 

 associated. Sometimes a single tree or variety in an orchard 

 will have the black rot much worse than others, and if it is an 

 early variety it may furnish a source of infection ; in such 

 cases the rotten fruit should be gathered up and burned. 



The Fire Blight {Bacillus amylovorus Burl.) is sometimes 

 common upon the apple, causing the young twigs to die and 

 the leaves to hang lifeless for the remainder of the season. 

 This is much more vigorous and destructive upon the pear 

 and will be treated later with the suggested remedies. 



The Powdery Mildew {Podosphcera oxycantha D C.) is often 



