NEW YORK EXPERIMENT STATION BULLETINS. 397 



now thinks this was a great mistake. He would not advise any one to set 

 trees in a locality where there are old plum or cherry trees covered with 

 black-knot. 



At a meeting of the Western New York Horticultural society held in 

 Rochester, January 27, 1892, the following resolutions were unanimously 

 adopted: 



Whereas, The interest we here represent involves expenditure and a large outlay 

 of capital for years before any adequate returns are received; and 



Whereas, The risks attending the growing of fruit from the depredations of insect 

 life and fungoid diseases are so rapidly on the. increase as to be a source of the greatest 

 anxiety and alarm to all engaged in the business; and 



Whereas, At this time there is great reason to fear that the total extermination of 

 the plum and cherry orchards of the state may follow the rapid spread of one of these 

 diseases, which science has demonstrated may be arrested in its destructive work by 

 the enforcement of a proper law, such as has already been enacted for stamping out 

 the disease in peach trees known as the peach yellows; now, therefore 



Resolved, That it is the unanimous sense of the fruitgrowers in this meeting 

 assembled, that it is of vital importance to them, and their interests demand that the 

 legislature of this state shall, without delay, enact such a law as shall, in its enforce- 

 ment and execution, thoroughly and effectually exterminate that infectious and 

 incurable disease known as black-knot. 



Mr. S. D. Willaed of Geneva was appointed a committee to draft such 

 a law and present it to the legislature. At the present writing the law 

 has been introduced into the legislature and will undoubtedly be passed. 



It is believed therefore that a bulletin giving the life history of the 

 fungus which causes black-knot, although the facts presented are not new 

 to science, will be especially valuable at the present time because there 

 are yet many persons interested in plum culture who do not realize the 

 very dangerous and destructive character of the disease and who have no 

 definite idea of its cause and the means by which it rapidly spreads from 

 tree to tree. 



A more general understanding of the reasonableness of the legislation 

 referred to and of the importance of vigorously following its provisions 

 will undoubtedly insure the hearty support and thorough enforcement of 

 this law. 



CAUSE OF THE DISEASE. 



It was formerly believed that black-knot was produced by some gall insect, 

 and it is not strange that this opinion prevailed on account of the gall-like 

 character of the knots and the fact that they are frequently infested by 

 insects. Some believe it to be the work of the curculio, others thought 

 that it was not the curculio, but some other insect or cause that produced 

 the knots. But several years ago Dr. Farlow published in the First Annual 

 Report of the Bussey Institute the results of his investigations which 

 proved conclusively that black-knot is caused solely by a parasitic fungus 

 which grows within the bark and which is now known to science by the 

 name of Plowrightia morbosa. 



It is recognized as growing on cultivated cherries and also on the wild 

 red or yellow plum (Primus Americana), the Chicasaw plum (P. 

 Chicasa), the choke-cherry (P. Virginiana), the wild red cherry (P. 

 Pennsylvania), and the wild black cherry (P. serotina). 



It is commonly most destructive to the plum but also seriously attacks 



