This disease is caused by the
fungus Pucciniachrysanthemi. Rust infection causes pale areas to
appear on upper leaf surfaces, with powdery orange pustules or spots directly
beneath on the undersides of the leaves. Severely infected plants are much
weakened and fail to bloom properly.
infected leaves as soon as possible. Set new plants farther apart and provide
better ventilation. Water the soil without wetting the plants. If disease is
severe enough to warrant chemical control, use a fungicide with mancozeb as
active ingredient. Some chrysanthemum varieties, which are resistant to rust,
are `Achievement`, `Copper Bowl`, `Escapade`, `Helen Castle`, `Mandalay`, `Matador`,
`Miss Atlanta`, `Orange Bowl`, and `Powder Puff`.
Examples of Fungicides(Myclobutanil - Neem
Oil – Propiconazole - Thiophanate-methyl