244 FARM FRIENDS AND FARM FOES 



the foliage of the whole tree. In such cases the young 

 peaches are likely to drop off, and the crop be thus de- 

 stroyed. A new set of leaves will be put forth, but of course 

 the tree will be unable to produce the same season another 

 crop of blossoms and young fruit 



Fortunately this disease is readily prevented by spraying 

 with fungicides. Winter treatment with Bordeaux mixture 

 or the lime-sulphur wash is an effective remedy. This is 

 believed to be due to the fact that the spores of the fungus 

 pass the winter chiefly on the bark and buds of the trees, 

 so that they are killed by the fungicide. 



Plum Pockets 



The Peach Leaf Curl is due to the growth of a parasitic 

 fungus that belongs to the genus Exoascus. The fungi of 

 this genus cause abnormal growths of the plants they in- 

 fest. The curious "witches brooms " often seen upon birch 

 and other trees are due to these parasites. So, also, are the 

 strangely swollen plums often seen upon the plum trees and 

 commonly called Plum Pockets. 



Young plums are generally affected by the Plum-pocket 

 disease. They become swollen, and when cut open are 

 seen to be hollow, with no pit. After a time they are likely 

 to be covered with a powder composed of the microscopic 

 spores of the fungus. These spores are widely scattered 

 by wind and rain, and presumably infest other trees, though 

 just how this is done is not now known. 



It is known, however, that the threads of the fungus live 

 from year to year in the twigs and reach the young fruits 

 by growing through the blossom or fruit stalks. When a 

 branch is once infested, it bears the Plum Pockets year after 

 year, and all new twigs sent out by it beyond the point of 



