THE PEACHES OF NEW YORK 121 



way. we are indebted for the first reference to what is now considered the 

 most certain symptom of yellows — premature ripening of frviit. Prince 

 says: 



" This disease, which commenced its ravages in New Jersey and 

 Pennsylvania about the year 1797, and in New York in 1801, and has 

 spread through several of 'the states, is by far more destructive to peach 

 trees than the worm, and is evidently contagious. This disease is spread 

 at the time when the trees are in bloom, and is disseminated by the pollen 

 or farina blowing from the flowers of diseased trees, and impregnating the 

 flowers of those which are healthy, and which is quickly circulated by the 

 sap through the branches, foliage, and fruit, causing the fruit, wherever the 

 infection extends, to ripen prematurely. That this disease is entirely 

 distinct from the worm, is sufificienth' proved by the circumstance, that 

 peach trees which have been inoculated on plum or almond stocks, though 

 less affected by the worm, are equally subject to the yellows — and a 

 decisive proof of its being contagious is, that a healthy tree, inoculated from 

 a branch of a diseased one, instead of restoring the graft to vigour and 

 health, immediately becomes itself infected with the disease. As all efforts 

 totally to subdue it must reqviire a long course of time, the best method 

 to pursue towards its eventual eradication, is to stop its progress, and 

 prevent its farther extension — to accomplish which, the following means 

 are recommended, which have been found particularly successful. 



" As soon as a tree is discovered to possess the characteristics of the 

 disease, which is generally known by the leaves putting on a sickly yellow 

 appearance — but of which the premature ripening of the fruit is a decisive 

 proof — it should be marked, so as to be removed the ensuing autumn, 

 which must be done without fail, for if left again to bloom, it would impart 

 the disease to many others in its vicinity; care is also necessary, in its 

 removal, to take out all the roots of the diseased tree, especially if another 

 is to be planted in the same place, so that the roots of the tree to be planted 

 may not come in contact with any of those of the one which was diseased. 



" If your neighbour has trees infected with the yellows in a quarter 

 contiguous to yours, it will be necessary to prevail on him to remove them, 

 that yours may not be injured by them. By being thus particular in 

 speedily removing such trees as may be infected, the disease is prevented 

 from extending itself to the rest of the orchard, and the residue will con- 

 sequently be preserved in perfect health at the trifling loss of a few trees 

 annually from a large orchard." 



The influence of yellows on the peach -industry of the country is shown 

 by indicating when it appeared in the various states in which peaches are 

 grown in eastern America and by noting the effects of epidemics of the 

 disease. 



