INSECTS, DISEASES AND SPRAYING 6l 



grower may not find that severe pruning will 

 rid a plant of the pest when it is thoroughly 

 infested. Therefore, as with the raspberry 

 rust, it may be necessary to root out and 

 destroy the rose bush and start again with a 

 healthy plant. This rose rust is a good illus- 

 tration of the great depth to which a fungus 

 will penetrate in the host and the difficulty 

 of eradicating the same. It goes without 

 saying that ordinary sprays will be of little 

 curative effect upon a plant when the living 

 vegetative threads of its fungous parasite 

 penetrate to all parts. 



In California the rust upon roses is very 

 much worse than it is in the East — sometimes 

 every leaf upon a shrub is badly affected. In 

 such a warm climate, when the plants retain 

 their foliage throughout the year, the dark 

 winter spores not being needed, are omitted 

 in the life cycle of the fungus and the orange- 

 coloured form of summer is perennial. 



The Rose Anthracnose is chiefly charac- 

 terised by the scarcity of leaves. Instead of 

 a plant with foliage upon all the canes there 

 are but few leaves upon some stems, while 

 others are entirely defoliated. The whole 

 plant is infested with the fungus, and this 



