Rose Black Spot

Rose black spot is  a fungal disease that affects rose plants. 

Symptoms: 

Purple or black spots on rose leaves, which often turn yellow and drop early.

Due to less leaf surface area it affects the growth of the plant as photosynthesis is reduced

Transmission:

Fungal spores are transmitted in the environment by both water and wind.

Wind-blown spores – The fungus produces spores on infected leaves. These can be carried by the wind to nearby rose plants.

Rain splash – Rainwater splashes the spores from infected leaves or soil onto healthy rose leaves, spreading infection.

Treatment: 

Remove infected leaves and stems, destroy these do not compost them. 

Spray roses with a fungicide designed for black spot