Coleosporium
domingense
syn C. plumeriae
Plumeria Rust Fungus, Frangipani Rust
Fungus
|
Plumeria leaf damaged by
Rust Fungus
(click image to enlarge). |
Frangipani
Rust usually affects Plumeria
(including:
P. acuminata, P.
acutifolia, P. alba,
P. clusioides,
P. rubra, P. obtusa,
and P. variegata)
in late summer and
early autumn in Florida especially
during and after very rainy periods.
Description of
Coleosporium Infection
Small orange pustules appear on the
underside of leaves. They rupture
and spread spores which pass the
disease to other leaves on the plant
and other Plumerias growing nearby.
The upper sides of the leaves become
discolored. The entire leaf turns
brown then falls off. Severe
infections may cause the leaves to
drop prematurely and tend to
defoliate the plant.
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 |
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Microscopic view of Coleosporium
domingense
infecting plumeria leaf
cells. |
Apparently the
fungus invades the epidermis of the
leaf, feeds on leaf cells and
spreads throughout the leaf by
rupturing leaf cell walls. The
orange pustules are fungal bodies
that produce spores which are spread
by wind and rain.
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 |
 |
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Frangipani fungus growing on
underside of leaf
(click
image to
enlarge) |
Plumeria leaf killed
by rust disease.
(click image to enlarge) |
Control of
Frangipani Rust
There are no fungicides listed for
use by the home gardener for control
of Coleosporium
domingense.
Limited control may be achieved by
removing infected leaves as soon as the
orange pustules are apparent and
disposing of those leaves in the trash.
A foliar spray of
the friendly fungi Verticillium
lecanii has been found an
effective control in research carried
out at the University of Florida.
Unfortunately this friendly fungi is
apparently not currently available
commercially for purchase by the home
gardener.
As Frangipanis
are normally deciduous, they will lose
their leaves anyway as the cooler months
approach and the problem will not
reappear until the wet season the
following year. Coleosporium
domingense does not affect
Plumeria flowers.
Sources:
BIOLOGICAL CONTROL OF FRANGIPANI
RUST WITH VERTICILLIUM LECANNI;
First
Report of Plumeria Rust, Caused by
Coleosporium plumeriae, in Thailand;
Frangipani rust |
