146 Report of the Depabtment of Botany of the 



to be known as a " sterile " fungus. Grossenbacher and Dug-gar 1 

 found, however, that instead of being sterile the fungus possesses 

 three conspicuous spore forms belonging to the genera Macro- 

 phoma, Dothiorella and Botryospha^ria respectively. They found, 

 also, that in spite of this wealth of spore forms infection appar- 

 ently does not occur until after the middle of June. Therefore, 

 it would seem as if the removal of affected canes in the spring 

 should be decidedly helpful in keeping the disease under control. 

 Winter pruning, on the contrary, is obviously ineffectual owing to 

 the difficulty of detecting diseased canes while the bushes are bare 

 of foliage. 



i & v 



TREATMEXT EXPERIMENTS BEGUX. 



Finally, in the spring of 1907 some treatment experiments 

 were started at Milton, X. Y. It was realized, at the outset, that 

 to rejuvenate an old, badly diseased plantation would be 

 more difficult than simply to keep the disease from becoming 

 established in a young plantation. So two experiments were com- 

 menced, one in a badly diseased twelve-year-old plantation and 

 the other in a moderately affected one-year-old plantation. The 

 former experiment was so planned as to show the effect of spray- 

 ing and summer priming separately and in combination. Bor- 

 deaux mixture was the fungicide used. It is unnecessary to give 

 the details of the experiment. Before the close of the second 

 season we became convinced that, under the prevailing conditions, 

 the disease could not be controlled. In most of the plants the 

 fungus had become firmly intrenched in the crown where it could 

 not be entirely removed by pruning. Accordingly, the experiment 

 in the old plantation was abandoned. 



THE PRIX T CTPAL EXPERIMEXT. 



The experiment in the young plantation appeared more promis- 

 ing. The object of this experiment was fo determine if necrosis 



i Grossenbacher and Dupgar. Lgf. cit. 



