PEACH YELLOWS. 231 



near the surface of the 2:i'Ound, and often totally encircles it ; the other is a disease 

 usually denominated the yellows. [Here follows an account of the borer.] 



Yellows. —This disease which commenced its ravages in New Jersey and Pennsyl- 

 vania 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 dis- 

 seminated by the pollen or farina blowing from the flowers of the diseased trees, and 

 impregnating the flowers of those which are health j' and which is quickly circulated 

 by the sap through the branches, and fruit, causing the fruit, wherever the infection 

 extends, lo ripen prematurely. That this disease is entirely distinct from the worm i& 

 sufficiently proved by the circumstance that peach trees which liave 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 vigor and health, 

 immediately becomes itself infected with the disease. As all efforts totally to subdue 

 it must require a long course of time, the best method to pursue towards its eventual 

 eradication is to stop its* progress and prevent its further 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 sickl}^ yellow appearance — but of which 

 the premature ripening of the fruit is 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 neces- 

 sary 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 planted may not come 

 in contact with any of those of the one which was diseased. 



If your neighbor has trees infected with the yellows in a quarter contiguous to 

 yours, it will he 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 icself to the rest of the orchard, 

 and the residue will constantly be preserved in perfect health at the trifling loss of a 

 few trees annually from a large orchard. 



"A distant subscriber," writing to The New York Farmer in 1831 (p. 154), 

 also mentions premature fruit. He says: 



Notwithstanding the wide destruction that the yellows has made, very few even at 

 this day appear to understand the unerring symptoms of the disase. Let me say when 

 the fruit ripens prematurely, from two to four weeks before the ordinary time, and the 

 pulp is marked by purple discolorations, then beware ! 



EXTENSION OF YELLOWS SINCE 1830. 



The disease extended somewhat slowly, and its general movement appears 

 worthy of special consideration, particularly as this may throw some light 

 upon the nature of the disease. It may be noted, however, that it continued 

 to prevail in the country about Philadelphia, where it was originally discovered, 

 as shown by the following citations : 



In 1838, in the Farmer's Cabinet, it is styled " that most insidious and 

 fatal disease of the peach tree, the yellows." 



In 1839 the same journal prints the following from the pen of a corre- 

 spondent: 



The worm (^greria) and the yellows are two great contemporary evils, which prob- 

 ably have no necessary connection with each other. The worm does not inquire 

 whether the devoted tree is sick or in health; the yellows is not always followed by its 

 ravages. 



In 1847 the following appeared in the Farmer and Mechanic: 



For many years the peach tree has been subject to a disease known as the yellows. 

 This disease seldom makes its appearance before the tree has arrived at maturity, as 

 its great vigor and rapid growth appear to preclude the development of the disease 

 previous to the tree fruiting. Much time, gmd labor, and research have been spent in 



