A fungal disease of Roses that starts as water soaked spots that soon turn into round, black to brown spots with distinct edges. As they increase in size the edges tend to become purple, the centre may dry out and become grey and fall out leaving a hole in the leaf. The leaves may go yellow in heavy infections and some may fall. Occasionally, spots may appear on stems and flowers.
Species Affected:
Spores are spread by wind.
Biology:
Favoured by cool, humid weather.
Some varieties are more seriously affected than others. Growth from the rootstocks such as Rosa multiflora are often seriously infected.
Life Cycle:
Origin and History:
Distribution:
Uncommon in warm coastal areas.
Significance:
Management and Control:
Choose verities with greater tolerance.
Apply fungicides. Black Spot spray programs usually control this disease.
Related and Similar Species:
Black Spot is quite similar.
References:
1205
Acknowledgments:
Collated by HerbiGuide. Phone 08 98444064 for more information.