DECAY OF THE PEACH TREE. 



progress of this diseased condition has evidently advanced farther in the eastern states, 

 than in the newer and more fertile regions of the vt'est. 



A knowledge of the pathology of a disease, whether in the animal or vegetable king- 

 dom, often leads to the discovery of successful means of cure. With this view, attention 

 has been directed to the nature and causes of this disorder. So far as they have been dis- 

 covered, they seem to be dependant on the following, " to wit :" 



1st. Tlie depredations of the jUgeria exitiosa, or Borer. — The first stage of impair- 

 ment was probably ertablished by the attacks of this insect. It was known as earl}'', or 

 before the commencement of the present century, yet it was then met with only in limited 

 numbers, and its depredations hardly attracted attention. At this time it has become so 

 numerous that every peach tree is annually assailed by from half a dozen to a dozen indi- 

 viduals, in the larvae state. 



The}^ perforate the crown of the roots, and excavate it so extensively as to nearly cut off 

 all communication with the body. Before the injury they inflict in one year is corrected 

 by the growth of the ensuing season, a second generation renews the attack. The tree 

 finally sinks under repeated injuries, or perhaps spins out a sickly existence for a few 

 years. 



2d. Exhaustion of the Soil. — No species of tree, shrub, or vegetable, can retain health, 

 vigor and productiveness, without a requisite supply of inorganic elements in tlie soil. 

 Few soils originally contain supplies sufficient to sustain a successive growth of the same 

 species of trees, in the same locality. When a forest is suddenly removed, its place is sure 

 to be occupied by a different growth of timber, and an attempt at cultivating the same kind 

 of crop upon the same field, repeatedly, is sure to be met with manifestations of exhaus- 

 tion, in the form of disease and unproductiveness. 



Such evidences are now too common with the peach tree, when it is planted on soils ex- 

 hausted of the essential elements. The doctrine is not perhaps exploded, that the excre- 

 tions of vegetables exert an unfavorable influence on a succeeding crop of a similar kind. 

 If it be correct, it may aid in throwing light on the nature and causes of the decay of the 

 peach tree. 



3d. The Curl of the Leaf. — Of late years, the first developed leaves in the spring sea- 

 son, become diseased with a spongy and malignant growth, which, in a few days' time, oc- 

 casions them to fall. This occurs at a period when the vigorous circulation of the sap re- 

 quires a corresponding action in those important organs. A second growth is soon forced 

 out, which ultimately restores the tree apparently to its wonted health and vigor. 



It is, however, evident, that though the recuperative powers of nature may for once, 

 twice, or even thrice, restore a growth of leaves, the shock must at length impair 

 the vitality, and induce an unhealthy condition. This curl of the leaf is produced by the 

 punctures of a small plant louse, perhaps the jJphis persica, or its analogue. It is de- 

 scribed by Dr. Harris in his Treatise on Destructive Insects, also in Kollar's work, to 

 which the reader is referred. 



People judging of the size of this insect from the extent of its injurious impressions, 

 might overlook it, expecting to find a huge monster where a mite exists, or very likely by 

 searching for it long after its day and generation had passed away. 



4th. The Yellows. — It is questionable whether anydistinct disease occurs, to which 

 this name is applicable. Perhaps it is only a collection of symptoms arising from 

 causes previously noticed — acting either individually or collectively. Facts seem to favor 

 this view — though the insight of popular opinion is in favor of its being a specif 

 contag-ious disease 



