Anthracnose Disease of Ornamental Plants: A Pictorial

Stephen H. Brown, Horticulture Agent
Lee County Extension, Fort Myers, Florida
(239) 533-7513 [email protected]
http://lee.ifas.ufl.edu/hort/GardenHome.shtml
Aaron Palmateer, Plant Pathologist
Tropical REC, Homestead, Florida [email protected]

Anthracnose Disease of Ornamental Plants:
A Pictorial

One of the most common diseases of plants is Colletotrichum leaf spot, or anthracnose. The Colleto-
trichum sp. that is most often present is C. gloeosportioides. Several other species have been identified
in infections of various hosts. Frequently, the perfect stage of the pathogen, Glomerella spp., is also pre-
sent in infected tissue.

Anthracnose disease may be confused with numerous other occurring plant diseases. Often laboratory
analysis is the only way to confirm the presents of the disease. Infection often first become apparent at a
portion of the leaf margin. The affected plant tissue frequently progresses from chlorotic to necrotic.
Infected leaves develop tan to reddish brown lesions that are typically associated with leaf veins; leaves
that have already expanded may become cupped and distorted with large areas of dead tissues. In severe
cases leaf drop occurs.

This pathogen spreads by spores that are easy to splash with irrigation water or rainfall but since they are
somewhat sticky they do not easily spread by simple air movement from the wind or fans. Wounding
can increase disease severity but it is not necessary for pathogen entry.

To manage the disease, rake and destroy fallen leaves, prune out dead or infected branches, mulch and
water during dry periods. Better control is more likely when fungicides are applied on a 7 to 10 day
interval compared to a 14 day interval. This is especially apparent during the rainy season when spores
of the pathogen are actively splashing. For this pathogen, spraying weekly in a preventative manner may
be necessary to obtain the optimal results. Products recommended for managing Colletotrichum contain
Chlorothalonil (Daconil Ultrex, etc.) pyraclostrobin + boscalid (Pageant, etc.) and Chlorothalonil + thio-
phanate methyl (Spectro 90WDG). Click here for a publication on recommended fungicides for this
disease.

The months associated with the pictures do not necessarily reflect the time of occurrence or expression
of the disease. In some cases, the disease may be present on the plant year round.

Table of Content Botanical Name Page
Agapanthus africanus 3
Common Name Bixa orellana 4
Agapanthus Viburnum odoratissimum awabuki 4
Annato Clusia rosea 5
Awabuki Begonia spp. 6
Autograph Tree Stachytarpheta jamaicensis 7
Begonia Zamia furfuracea 7
Blue Porterweed Carissa macrocarpa 8
Cardboard Palm Aspidistra elatior 8
Carissa Crinum asiaticum 9
Cast Iron Plant Adenium obesum 10
Crinum Lily Schefflera arboricola 11
Desert Rose Campylonerium phyllitidis 12
Dwarf Schefflera Wodyetia bifurcata 13
Elk-Horn Fern Duranta erecta ’Gold Mound’ 14
Foxtail Palm Ficus microcarpa ‘Green Island’ 14
Gold Mound Hibiscus rosa-sinensis 15
Green Island Ficus Raphiolepis indica 16
Hibiscus Ixora coccinea 17
Indian Hawthorn Jatropha integerrima 17
Ixora Cycas revoluta 18
Jatropha Mandevilla splendens 19
King Sago Mangnifera indica 19—20
Mandevilla Snaseviera trifasciata 21
Mango Ficus aurea 22
Snake Plant Viburnum odaratissimum 23
Strangler Fig Philodendron selloum 24
Sweet Viburnum Strelitzia nicolai 25
Tree Philodendron Philodendron ’Xanadu’ 26
White Bird of Paradise
Xanadu

Agapanthus (Agapanthus africanus)

Annato (Bixa orellana) October

Awabuki (Viburnum odoratissimum awabuki) August

Front of leaves Back of leaves

Autograph Tree (Clusia rosea) June

Front of leaves Back of leaves
Autograph Tree as a hedge

Begonia (Begonia spp.) June
November

Blue Porterweed (Stachytarpheta jamaicensis) September

Cardboard Palm (Zamia furfuracea) August

Carissa (Carissa macrocarpa) November

Front of leaves Back of leaves

Cast Iron Plant (Aspidistra elatior) October

Crinum Lily (Crinum asiaticum) November

More on crinum lily

Desert Rose (Adenium obesum) September

Front of leaves Back of leaves

Dwarf Schefflera (Schefflera arboricola) July

Dwarf Schefflera as a hedge

Elk-horn Fern (Campylonerum phyllitidis) October

Front of leaves Back of leaves

Foxtail Palm (Wodyetia bifurcata) July
January

Gold Mound (Duranta erecta ‘Gold Mound’) October

’Green Island’ Ficus (Ficus microcarpa)

Hibiscus (Hibiscus rosa-sinensis) January

Front of leaves

Back of leaves Insect problems of Hibiscus
Hibiscus as a hedge

Indian Hawthorn (Raphiolepis indica) August

Left: Non-symptomatic leaves
Right: Leaves with Anthracnose symptom

Diseases of Indian Hawthorn

Ixora (Ixora coccinea) July

Ixora as a hedge December

Jatropha (Jatropha integerrima)

King Sago (Cycas revoluta)

Mandevilla (Mandevilla splendens) July

Front of leaves Back of leaves

Mango (Magnifera indica) July

Mango (Magnifera indica) April

July

November

More on Mango

Snake Plant (Sansevieria trifasciata)

Strangler Fig (Ficus aurea) December

Front of leaves Back of leaves
More on the Strangler Fig

Sweet Viburnum (Viburnum odoratissimum)

Tree Philodendron (Philldendron selloum) October

White Bird of Paradise (Strelitzia nicolai) October

Xanadu (Philodendron ‘Xanadu’) May

An Incomplete List of ornamental plants that are host to Anthracnose

Common Name Botanical Name

Anthurium Anthurium andraeanum

Areca Palm Dypsis lutescens

Azalea Rhododendron hybrids

Bald Cypress Taxodium distichum

Banana (ornamental) Nymphioides spp.

Christmas Palm; Adonidia Palm Adonidia merrillii

Daylily Hemerocallis spp.

Eugenia Zyzgium paniculatum

Fig Ficus carica

Firecracker tree; peregrina Crinum asiaticum

Heavenly Bamboo Nandina domestica

Leatherleaf Fern Rumohra adiantriformis

Lilyturf Liriope muscari

Pomegranate Punica granatum

Mondograss (dwarf lilyturf) Ophiopogon japonicus

Pentas Pentas lanceolata

Rubber Plant Ficus elastica

Rose Rosa hybrids

Sycamore Platanus occidentalis

Weeping Fig Ficus benjamina

Yucca (spineless) Yucca spp.

All pictures taken by Stephen H. Brown, except where indicated.

Useful Links
Crinum Lily Fact Sheet
Diseases of Indian Hawthorn
Insect Problems of Hibiscus
Strangler Fig Fact Sheet

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Service, University of Florida, IFAS, Florida A. & M. .1/2012.