How to Manage Pests
UC Pest Management Guidelines
Floriculture and Ornamental Nurseries
Sweet William (Dianthus barbatus)
Disease Control Outlines
In this Guideline:
Disease (causal agent)
||Survival of pathogen and effect of environment
||Comments on control
f. sp. dianthi)
|Yellowing of new growth. Plants
stunted and leaves point downward instead of upward as in a healthy plant.
Leaves gradually turn yellow and die. The vascular system of the lower stem and roots is brown.
||Fungus survives in soil for many
years as chlamydospores. Disease is favored by warm soils and high temperatures.
||Fumigate soil with methyl bromide
to chloropicrin combination. Grow seedlings in heat‑treated, solarized,
or fumigated soil or growing medium. more info *
|Yellowish brown, withered spots
surrounded by a purplish margin on leaves. As the disease progresses, entire leaves and stems become necrotic.
||Spores (conidia) are airborne.
Fungus survives on Sweet William debris. Favored by wet weather and overhead irrigation.
||Avoid overhead irrigation. Protect foliage with a fungicide.
are also susceptible to rust * (Uromyces caryophyllinus and Puccinia areneriae), root rot * (Pythium ultimum), gray mold * (Botrytis cinerea), stem
rot (Rhizoctonia solani), southern blight * (Sclerotium rolfsii), Septoria leafspot (Septoria dianthi),
anther smut (Ustilago violucea), curly top (beet curly top virus), and aster yellows (aster yellows phytoplasma).
|* For additional information, see section on Key Diseases.
UC IPM Pest Management Guidelines: Floriculture and Ornamental Nurseries
UC ANR Publication 3392
S. T. Koike, UC Cooperative Extension Monterey County
C. A. Wilen, UC IPM Program, UC Cooperative Extension San Diego County
Acknowledgment for contributions to Diseases:
R. D. Raabe, (emeritus) Environmental Science, Policy, and Management (ESPM), UC Berkeley
A. H. McCain, (emeritus) Environmental Science, Policy, and Management (ESPM), UC Berkeley
M. E. Grebus, Plant Pathology, UC Riverside
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