CHAPTER XX. 



DISEASES TO WHICH THE ORANGE TREE AND FRUIT 

 ARE LIABLE, AND THEIR REMEDIES. 



fEW fruit trees are less liable to disease than the 

 orange, but the fruit and trees are so valuable 

 that no enemy should be allowed to attack them 

 unopposed. Perhaps the most formidable disease 

 which has yet made its appearance is the ' ' die-back. ' ' 

 One cause producing this disease has already 

 been noticed in a preceding chapter. The name 

 ' ' die-back' ' is a general term, used for want of a 

 better and more specific name or names, for at least 

 two diseases arising from three and perhaps four 

 different causes. But as it is descriptive of the 

 symptoms of one or more diseases arising from sev- 

 eral different causes, its meaning is readily com- 

 prehended. The symptom is the dying back of the 

 new wood to the old. It is sometimes confined to 

 a few branches of the tree. When this is the case 

 the inference is that it is caused solely from the 

 sting of an insect. If, however, the symptom is 

 general to the young branches, and they come forth 

 feeble and yellow with no marks of stings, the 

 cause may originate near the roots. 



Deep planting will produce such symptoms. 



