268 Report of the Department of Botany of the 



the vines at trimming time. In many respects the trimming of the 

 vine is the most important operation of the whole year and this is 

 unquestionably true when this disease is present. It is a most 

 unfortunate practice to leave the pruning of the vines to a so-called 

 professional "trimmer", unless the character of his work is well 

 known. It is even more unfortunate to hire the work done by the 

 acre. The writer has seen the work of some professionals which 

 could not be called good pruning and it was very evident that they 

 were either ignorant of or indifferent to methods of eliminating 

 disease. 



An eradication experiment. — When the writer began a serious 

 study of this disease in the spring of 1908, and before it was known 

 that the lesions on shoots were in any way comiected with the disease, 

 a number of affected vines, approximately 20 years old, were sawed 

 off near the ground and used for cultural and other studies. In 

 most cases a sucker was tied up in place of the vine removed. 



As such a method of renewal was being practiced by at least one 

 grower in Chautauqua county a record was made of twenty-three 

 vines thus removed. 



Although it was realized before the summer was over that a record 

 of the development of these renewals would mean little in regard 

 to the practicability of such a method of control, owing to the dis- 

 covery of the fact that the fungus produced infections on the shoots 

 and that some of the shoots tied up were unquestionably infected, 

 it was thought, nevertheless, that a sufficient number would be 

 found free from infection and enough others unquestionably affected 

 to make it worth while to keep a record of development. Accord- 

 ingly observations and records were made June 8, 1909, August 2, 

 1910, July 28, 1911, and July 26, 1912, which appear in Table I. 

 Those vines recorded as infected when tied up (condition in 1908) 

 were not examined until June 8, 1909, but at that time unmis- 

 takable lesions were evident on the canes. Those vines recorded as 

 questionable did not show lesions and persumably a number of them 

 were healthy. Vines 16 and 18, however, were undoubtedly in- 

 fected when they were tied up. 



Table I (pp. 270-1) shows that renewed vines may be brought into 

 profitable bearing quickly by the renewal system and also shows most 

 strikingly the slowness with which the fungus works. Some of the 



