CoRNELl, University, Ithaca, N. Y., December 15, 1894. 



The Honorable Commissioner of Agriculture, Albany, 



Sir .—The following account of the black-knot of plums and cherries is 

 submitted for publication and distribution under section 87, chapter 675, of 

 the laws of 1894. The subject is an important one to all fruit growers, and 

 the present account contains the first experimental proof that the disease can 

 be kept in check by spraying. The leading points established in this paper 

 are these : The disease usually shows itself the year following inoculation, a 

 fact which is proved by the absence of knots on the growth of the season ; 

 the inoculation occurs mostly in crotches and at the junctures of the annual 

 growiihs, owing to the greater frequency of chinks at these places, and to 

 more tender bark, and to convenient places for lodgement of the spores ; if 

 the branches are constantly covered with fungicide, the germinating spores 

 are killed. Good Bordeaux mixture remains upon the branches a long time, 

 and it appears to retain its efiicacy from the fact that when applications 

 ceased early in June the summer spores of the fungus, which no doubt ap- 

 peared after this time, were apparently unable to seriously multiply the 

 disease. Whilst the results with the spray are surprising, there is neverthe- 

 less every reason for anticipating them, for it is evident that the infection 

 takes place from spores falling upon the plant, and it is generally understood 

 that germinating spores are killed by copper fungicides. Mr. Lodeman's 

 results with the black-knot are supplemented by similar results obtained by 

 myself upon another fungus which enters the deep tissues, the red rust of 

 the quince (see Bulletin 80). L. H. Bailey. 



