252 Report ok the Department of Botany of the 



liminary report on a destructive disease of grapes, entitled Necrosis 

 of the Grape Vine. At the time of publication of that bulletin it 

 was realized that there were many points yet to be studied. Among 

 these should be mentioned, first of all, the absence of inoculation 

 experiments which would prove absolutely that the fungus found 

 constantly associated with the disease was really the primary cause 

 of it and not a secondary factor incidental to some other disorder. 

 A more extended survey of the distribution of the disease in the 

 vineyard regions of the State and a more intensive study of its 

 occurrence in individual vineyards seemed important. Careful 

 observations and experiments were necessary on the method by 

 which the disease spreads. This seemed particularly true with 

 respect to the possibility of spread of the disease through affected 

 nursery stock. Finally, control experiments based upon the above 

 findings were of utmost practical importance. 



Through opportunity to work at the vineyard laboratory of the 

 Station during the summers of 1909 and 1910 a number of these 

 points have been cleared up and a satisfactory report of progress 

 of the investigations can now be made. Although this report is 

 intended primarily to supplement and extend the work reported 

 in the Cornell bulletin, certain portions of the information recorded 

 there is repeated inasmuch as the edition of that bulletin is exhausted. 



THE DISEASE. 



NAME. 



The name most commonly applied to this disease is dead-arm 

 or side-arm disease. The writer undertook to introduce the name 

 necrosis, which still appeals to him as a good name for this type of 

 disease, but unfortunately he was not aware, until the fact was 

 pointed out, in 1911, by Dr. Shear, of the United States Department 

 of Agriculture, that this name had already been used by Cavara 

 (1897) to designate a bacterial disease of the grape occurring in 

 Europe, said to be caused by Bacillus vitivorus. It therefore seems 

 advisable to go back to the well-established name of dead-arm 

 disease. 



OCCURRENCE. 



The disease occurs on practically every variety of the grape grown 

 commercially in the State. Naturally it is most frequently met with 



