266 Report of the Department of Botany of the 



The first lot of cuttings did not have the most favorable conditions 

 for growth, but the second lot was favored in every way. It seems 

 quite evident therefore that the high percentage of mortality must 

 be credited to the dead-arm fungus. If this is the case, the disease 

 in this phase of its development is one of interest primarily to the 

 nurserymen, and the transmission of the disease through nursery 

 stock would appear to be of little consequence. Unfortunately it 

 is now evident that the experiment was not perfectly planned. The 

 cuttings used in both of the experiments were quite badly or even 

 severely infected when they were taken. While the writer is not 

 thoroughly familiar with the practice of nurserymen with respect 

 to making cuttings it would seem that the very short internodes 

 near the base of the cane would not serve particularly well for this 

 purpose and it seems rather doubtful whether badly diseased inter- 

 nodes would be saved for cuttings. In any case such a practice in 

 the future is very unwise for the nurseryman. The experiment 

 would have been of much greater value if canes bearing only one 

 or two spots or possibly half a dozen had been used. Such condi- 

 tions would have given the cutting every chance to become es- 

 tablished and at the same time would prolong the time until the 

 fungus could spread to various parts of the tissue. It is quite prob- 

 able that such cuttings would make vines that could be sold and 

 which might grow for several years without showing marked evi- 

 dence of disease. 



CONTROL. 



ERADICATION. 



The method of control described in the former bulletin is still 

 the best and most obvious way of holding this disease in subjection. 

 Since the publication of that bulletin a great many growers in Chau- 

 tauqua county have given more attention to the prompt removal 

 of diseased wood and the renewal of the vines with new growth 

 from below the surface of the ground. However, certain features 

 are still open for great improvement. Many persons apparently 

 are not yet fully conversant with the fact that the vines which show 

 a dwarfed, crimped and yellow-colored leaf during the early part of 

 the season are affected with the dead-arm disease. This character- 

 istic symptom is of the greatest value in locating vines in the first 



