^8 PROTECTION OF PLANTS — 1922-23 



colleges is too often ovei"shadowed by horticulture and agronomy, and pro ra- 

 ising students go into these lines of work; while in many of our colleges which 

 are not agricultural, the students are drilled in technical features of the subject 

 which have little or no interest or meaning to them. Here, th^ is the greatest 

 opportunity for the university department of botany.. All beginning students 

 should be given, not only the subject matter of the course, but the broadest pos- 

 sible view of the subject as a whole in all its relations to other sciences, to human 

 welfare and to the wealth and progress of the nations of the world. Fortunately 

 the American Phytopatjbological Society has not broken away from the mother 

 science. We hold our meetings at the same time and in some cases hold joint 

 meetings with section G of the American Association for the Advancement of 

 Science and with the Botanical Society of America. We co-operate with the 

 mother subject to the fullest extent. We are also in close contact with the 

 agricult)ural industries. Therefore the conditions are most favorable for the 

 future development in the New World of the highest possible type of botany in 

 general and of plant pathology in particular. 



SOME NOTES ON SPRAY MATTERS. 

 By L. Caesar, Provincial Entomologist, Guelph, Ont. 



Spraying Currants to Prevent Defoliation. 



In Quebec as in Ontario it is probably a common occurrence for currant 

 bushes, especially black currants, to lose all or nearly all their foliage prema- 

 turely, the defoliation sometimes occurring in July even before the fruit is picked 

 and sometimes in August. 



The chief cause of this leaf drop, so far as my experience goes, is the leaf 

 spot or anthracnose disease (Pseudopeziza ribis, though the other common leaf 

 spot (Mycosphoerella grossularicb) may also be a factor. 



The condition favouring leaf spot is wet weather. If much wet weather 

 occurs in May or June there is almost sure to be a heavy defoliation often as 

 early as the end of July, especially the weather that month is hot and dry. 



Having observed this defoliation of black currants for several years and 

 believing that serious loss to the vigor and yield of the plants must result there- 



