XI 



DISEASES OF TREE AND FRUIT 



Although the peach is fully acclimated to the con- 

 tinent of North America and seems to be perfectly 

 at home here, it is by no means such a sturdy and 

 healthy tree as the apple. It seems to be a short- 

 lived, weak and uncertain tree subject to various 

 accidents and diseases. While an apple orchard is 

 expected to live and thrive during more than a man's 

 natural lifetime, a peach orchard is hardly expected 

 to be profitable for more than 15 or 20 years. This 

 relatively early disappearance of the trees is brought 

 about by various causes, but largely by the insidious 

 attacks of several serious diseases. Most important 

 of these are (a) yellows and its close relative, the 

 rosette, (b) a somewhat similar disease recently dis- 

 covered and known as "little peach," (c) the brown 

 rot, (d) the scab and (e) the leaf curl. 



THE YELLOWS 



This is one of the most serious diseases which 

 attacks the peach tree and one of the most difficult 

 to meet, and part of this difficulty lies in the fact 

 that the cause of the disease is still unknown, although 

 many of the best scientists of the world have studied 

 the subject for many years. The following interest- 

 ing characterization of the disease is made by Prof. 

 L. H. Bailey: "The yellows is a distinct disease. It 

 is not a condition. It attacks peach trees of all ages 

 and in all conditions of vigor, seeming to have a 

 preference for those that are thrifty. It is incurable 



134 



