11 



blight is not so serious in our section on the apple as on the 

 pear and quince. 



The principal methods of control consist in pruning out 

 the infected limbs, at least a few inches below the affected 

 region. Fall and winter pruning is considered better than 

 summer pruning, since the affected parts may be more readily 

 found, whereas in summer the disease may be spreading 

 rapidly and all of it may not be eradicated. In all cases of 

 pruning, antiseptic methods should be employed, such as 

 sterilizing with formalin or some other substance the tools 

 used in pruning, or treating the cut surfaces with creosote, etc. 



PowDEiJY Mildew (Erysiphe Polygoni DC). 



This mildew is seldom found on apples in this section. It 

 occurs on nursery stock in some regions, where it causes more 

 or less injury in the form of a mildew effect on the upper 

 surface of the leaf. 



Ckown Gall. 



• 



Crown gall (Fig. T) has caused vexation and worry to 

 many fruit growers for the past few years, although the 

 amount of actual injury done is somewhat problematical. 

 For a few years considerable infected apple stock came into 

 our State from outside, but for the past four or five years 

 orchardists have been more particular about their material, 

 and cleaner stock has been obtainable. There are only a 

 few instances where trees have been so severely affected as to 

 die, but one never knows when complications may set in and 

 result in loss. 



There are many forms of galls affecting plants, but prac- 

 tically all have a similar distorting effect on the tissue, which 

 may seriously interfere with the vital processes of the plant. 

 Eel worm galls, which are similar in appearance to those 

 found on the apple tree roots, cause little injury to tomatoes 

 and cucumbers, but are very injurious to roses, violets and 

 melons, and in the south, various other crops, including some 

 trees, are affected. 



There is much difference of opinion as to the effect of crown 



