PESTS AND SPRAYING. 107 



is best combated by the removal and burning of the 

 leaves infected and the spraying- of the tree with a 

 good insecticide. Black Spot should be treated in like 

 manner to Rose Rust, as it is almost as common, and 

 develops very quickly. It is generally found in Rose 

 gardens that are too shut in or that possess poor, dry 

 soils. Rose Leaf-scorch is another fungus pest, but 

 it is not a common one. Not unlike Rose Rust, this 

 plague is even more deadly when it attacks the foliage 

 of trees, for the leaves drop off very quickly, in which 

 case they are best gathered up and burnt. 



Yet another fungus pest, Sooty Mould, often, 

 makes its appearance in certain localities. The name 

 well describes the disease, and it is found present on 

 both wild and cultivated Roses. This fungus, beyond 

 choking the pores of the leaves, does not take its sus- 

 tenance from the foliage, but from the " honey dew " 

 deposited by the Aphides or " greenfly " on it. There- 

 fore, let not that Rosarian mention the presence of 

 such a pest, for his is the neglect and fault. 



Rose Tree Canker, found with some varieties of 

 Roses more than others, generally attacks the tree at 

 the point of union between stock and scion. William 

 Allan Richardson and Marechal Niel are two varieties 

 often affected, as also arc many of the climbing Tea 

 Roses. 



I know of no cure, and much doubt if the disease 

 does more than shorten the possible life of a long-lived 

 tree by a year or two. It seems to come from the re- 

 stricted flow of sap, caused by either the parent stock 

 or the grafted Rose being the one more vigorous than 

 the other. This you cannot always help, for it is not 

 easy to define exactly the requirements of every 

 Rose, and, when we consider it, growers have not 

 studied the varieties of the Dog Rose so closely that 

 they can make any diff"erence in foster-parent selection 

 for the would-be child. 



