30 



Journal of Agriculture, Victoria. [10 Jan., 1919. 



attacked. On the presence of the pest being discovered in these parts 

 the infested trees and those around them should be carefully treated 

 in the way suggested, in order to prevent the spread of infection, and 

 obviate the necessity of more extensive and expensive treatment, Avhich 

 invariably follows early neglect. As this pest is fairly amenable to 

 treatment under the principles of isolation, much of the devastation 

 caused in many orchards could have been considerably reduced had the 

 trouble received more careful attention during the early stages of 

 infection. 



Plate 183.— Emperor Alexander Apple Tree which has been 

 attacked by root borer. 



Plate 183 illustrates the apparent effect on the framework above 

 ground as a result of the roots being attacked by the borers. The tree 

 is of the Emperor Alexander variety, and ten years old. The decay- 

 ing points of the branches indicate that the " die-back " has consider- 

 ably advanced, and the presence of the borers is further evidenced by 

 the succulent growths which appear near the base of the leaders. 



The maintenance of the naturally high sap pressure is essential to 

 the production of uniformly strong and healthy growth in every part 



