Rust (Puccinia Species)

Plants/trees Affected
 
Trees, Shrubs, Roses, Hollyhocks, Antirrhinum (Snapdragons), Pelargoniums, Chrysanthemums, Fuchsias, Leeks and Broad Beans.

                         

Symptoms

Yellow patches on the top of leaves which can spread to the stems and powdery orange/brown raised spots on the lower sides of leaves.  Affected leaves tend to fall prematurely.

Causes

This is a fungal disease caused by any one of 4000 different types of the puccinia fungi.  The spores are distributed by wind, animal fur, insects, on hands or more commonly rain/water splash and thrive in hot humid weather.

Prevention

Good hygiene is the key to preventing rust, it is important to clear away and burn all leaf debris and affected plant material.  Prune plants to provide good air circulation and reduce the possibility of humid conditions both outdoors and in greenhouses. Clean/sterilize pruning tools after use on affected plants to avoid spreading the disease.   Don’t use overhead irrigation, water at the base of the plant and if possible in early morning to allow the plants time to dry out during the day.  Use rust resistant plant species.

Treatment

• Remove and burn all affected leaves and plant material.
• Spray regularly with fungicides such as Mancozeb, Penconazale & Flutriafol. At the end of the season use a Bordeaux mixture to kill over wintering spores.