Chrysanthemum White Rust - Watch for it!
Friday, 07 July 2006 12:52
Chrysanthemum white rust (Puccinia horiana) is a serious fungal disease of chrysanthemum. White rust can spread quickly in greenhouse and nursery environments causing severe crop losses in a crop of hardy mums.
The symptoms of chrysanthemum white rust are very distinct. Light green to yellow spots up to 5mm in diameter appear on the upper surface of the leaf. These spots become brown and necrotic with age. Raised beige to pink pustules form on the underside of leaves beneath the spots. Pustules become white with age. Pustules are most common on young leaves and flower bracts but may form on any green tissue or the petals. Symptoms usually occur during cool, wet weather.
The disease is brought in on infected plant materials. Infected plants may look normal until correct environmental conditions encourage symptom development. Hot and dry weather may delay onset of symptoms for up to eight weeks. Fungicide applications may suppress disease development. CWR can also be spread to uninfected plants on contaminated soil, litter, dead leaves, gardening equipment, clothes, shoes, and hands. The fungus only grows and reproduces on susceptible host plants.
For more information online:
Chrysanthemum White Rust
You can also do a Google Search using the words chrysanthemum white rust
Paul Lopes
