Coniothyrium Canker of Roses
A fungal disease of Roses that usually enters the plant via wounds. The stem is discoloured from the wound down the stem and is often forms a diagonal angle with a raised ridge between infected and healthy tissue. The plant normally halts the infection but occasionally it progresses causing a die back of stems.
The fungus may also enter where thorns pierce neighbouring stems during windy weather and pale yellow or reddish spots appear at puncture marks. These may expand and turn brown and the bark cracks.
On infected areas many tiny black fruiting bodies may appear containing spores.
Biology:The fungus is commonly found on the thorns of roses.
Life Cycle:Origin and History:
Management and Control:
Use sharp pruning tools.
Make angled cuts to reduce water sitting on wound.
Keep plants growing vigorously.
Prune off diseased portions just above a node about 100 mm below discoloured areas.
Fungicides are not effective.
Related and Similar Species:References:
Collated by HerbiGuide. Phone 08 98444064 or www.HerbiGuide.com.au for more information.