THE DISEASES OF THE FRUITS 143 



the most noticeable of these diseases is the leaf curl of the peach 

 which is a fungous disease occurring in the spring and causing 

 the leaves to curl, turn yellow or pinkish and finally drop. In 

 severe cases practically all the leaves fall. The tree puts out 

 new foliage but drops the fruit. The disease when once estab- 

 lished persists from year to year. It can be controlled by 

 proper spraying. 



The many leaf spot diseases (Fig. 88) reduce the amount 

 of leaf surface and thus reduce the amount of work which the 



' Fig. 89. — One of the apple rots, called "bitter rot." 



plant is capable of doing. Therefore, severe leaf injury will 

 usually result in reduced vitality and reduced yield. 



The diseases of the trunks of trees usually start with wounds 

 through which fungi gain entrance and cause heart rots. Spe- 

 cial care should be taken to protect street, shade and ornamental 

 trees against such injury. Tree wounds should be painted. The 

 filling of tree cavities is very satisfactory if well done. 



The diseases of the fruits may appear as deformities, spot- 

 tings and rots. (Figs. 89 and 00.) The great majority of these 

 diseases are due to fungi. If you will examine the rots on a 

 number of apples of various kinds you will be able to throw 



