Bright orange spots, or pustules develop on the upper leaf surface with corresponding bright orange spore masses beneath. Dark brown over-wintering spores will be seen from late summer/early autumn. Severely infected leaves will drop prematurely. The most common and obvious infections occur in early summer. Moist air is essential for the development and spread of rose rust. The fungus may persist in the plant stems and the spores can over-winter on the soil surface, on fallen plant debris.
Cultural control: Prune out stems showing early spring infections. This must be done promptly and thoroughly. Improve air circulation within the rose buses by pruning out unwanted branches, avoid planting out too closely. Remove and dispose of affected leaves or cut back/remove plants where appropriate. Avoid using too much nitrogen when feeding.
Product Solution:Multirose Concentrate 2, Multirose 2 Ready to Use, Fungus Fighter Disease Control or Systhane Fungus Fighter.