Detailed recommendations are given in the profiles available for rust diseases of individual plants and crops. General recommendations are as follows:
- The development of the disease can sometimes be slowed by picking off affected leaves as soon as they are seen, provided that this involves just a small number of leaves. Removing leaves in large numbers is likely to do more harm than good
- Provide conditions that encourage strong growth, but avoid an excess of nitrogen fertiliser as this results in soft, leafy growth that is easily colonised by rust
- All diseased and dead material should be removed at the end of the growing season. The overwintering spores of some rusts are very resilient, so do not compost affected material
- Resistant cultivars are available for some plants and crops, but this resistance is occasionally overcome by genetic changes within the rust fungus
- In some cases no control is required. For example, many rusts of trees develop too late in the summer to have a significant effect on vigour, even though the whole tree may appear yellow or orange in late summer due to the huge number of rust pustules on the leaves
Edibles and Ornamentals: Copper-based fungicides* (Vitax Bordeaux Mixture, Bayer Garden Fruit and Vegetable Disease Control) may be used to control rust on currents and gooseberries.
Ornamentals only: The fungicides myclobutanil* (Bayer Garden Systhane Fungus Fighter and other formulations), tebuconazole (Bayer Garden Multirose Concentrate 2) and triticonazole (Scotts Fungus Clear Ultra, Roseclear Ultra) are approved for the control of rust diseases of ornamental plants.
Some formulations also contain insecticides but these are best avoided if no insect pest problem is specifically identified. For example, some formulations of myclobutanil (Westland Rose Rescue) contain cypermethrin, some formulations of tebuconazole (Bayer Garden Multirose Concentrate 2) contain deltamethrin and some formulations of triticonazole (Scotts Roseclear Ultra and Scotts Roseclear Ultra Gun) contain acetamiprid.
The foliage and flowers of some ornamentals are sensitive to damage by certain fungicides, particularly some formulations of difenoconazole and myclobutanil. Check the product label before use.
*NB: The following products are being withdrawn:
Myclobutanil (Bayer Garden Systhane Fungus Fighter concentrate and Bayer Garden Fungus Fighter Disease Control). These products cannot be sold after the 30th November 2015 and remaining stocks must be used or disposed of before the 30th November 2016.
Bordeaux Mixture (Vitax) is being withdrawn and cannot be sold after the 30th November 2014 and remaining stocks must be used or disposed of before the 30th November 2015.
Copper oxychloride (Bayer Garden Fruit and Vegetable Disease Control) is being withdrawn and cannot be sold after the 30th November 2014 and remaining stocks must be used or disposed of before the 30th November 2015.
Fungicides for gardeners (Adobe Acrobat pdf document outlining fungicides available to gardeners)