Plant Diseases 
347 
VIOLET RUST 
This disease does not cause very great damage to the 
plants growing in the open borders, except in damp, cold 
seasons, which check the growth of the plants, and which 
favour the spread of the disease. But in damp, mild 
seasons, if the disease attacks cuttings in the frames, it 
sometimes does considerable damage, destroying the half- 
rooted cuttings wholesale. This trouble is not experienced 
to such an extent in districts where the cuttings can be 
struck outside. 
The disease first makes its appearance as little black 
spots caused by the mycelium devouring the contents of 
the cells and destroying them. The uredospores are then 
formed, and after a time the teleutospores are formed, 
which are of a dark -brown colour, and appear in small 
clusters here and there on the leaves. Of course the 
fruiting stage is the last stage of the disease. The 
mycelium, being inside the host plant (Viola), is secure 
from any substance which may be applied to cure it. If, 
however, there is any fear of attack, the plants may be 
sprayed with dilute Bordeaux mixture or Condy’s fluid. 
This will not cure the disease, but may prevent it spread- 
ing to other healthy leaves or plants. 
CHRYSANTHEMUM RUST 
This is another disease which at one time was thought 
to be of far greater importance than it is now. This is 
owing to the energetic efforts which were put forward at 
the time of its first appearance to stamp it out, efforts 
