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Mahona Rust


Mahona Rust

Usually appear in

All Year

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Caused By:-     The Fungus Cumminsiella mirabilissima


Mahonia Rust is caused by the fungus Cumminsiella mirabilissima and deep-red spots with dark centers throughout the year on the upper leaf of Mahonia species. On the undersides are powdery brown pustules. If left untreated it will spread tot he whole leaf and cause premature leaf fall. Most Rust is a fungal disease needs an alternate host to complete its life cycle, but C. mirabilissima appears to survive on one host. The pustules under the leaves are the spores which are carried by airborne spores. Mahonia are particularly susceptible during the damp weather between late Spring and Autumn, but this rust can rear up at any time of the year.
See also these other rusts Anemone, Antirrhinum, Bean, Bluebelle, Cedar Quince, Chrysanthemum White, Fucshia, Gladiolus, Gooseberry, Hollyhock, Juniper Pear, Mint, Pear Juniper, Pelargonium, Periwinkle, Plum, Potato Internal, Quince, Rhododendron, Rose, Rust, White.


Once your plant has rust, it's best to treat them with a fungicide, but, as ever, prevention is better than cure. Make sure you get rid of any infected leaves which have fallen around the plant, as the spores nest in them to lie in wait for the breeze to other Mahonias. This goes for leaves still attached to the plant - pull them off and burn them. Also, make sure your plants are well spaced and ventilated. You'll limit the chance getting this pest.

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