List of poinsettia diseases

This article is a list of diseases of poinsettia (Euphorbia pulcherrima).

Poinsettia growing in Barlovento, Canary Islands

Bacterial diseases

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Disease Cause Image
Bacterial leaf spot Curtobacterium flaccumfaciens = Corynebacterium flaccumfaciens pv. poinsettiae
Bacterial leaf spot Pseudomonas cichorii
 
Bacterial leaf spot Pseudomonas marginalis
 
Bacterial leaf spot Pseudomonas syringae subsp. syringae
Bacterial leaf spot Xanthomonas campestris pv. poinsettiaecola
Bacterial stem rot Erwinia carotovora subsp. carotovora
 
Bacterial stem rot Erwinia chrysanthemi
Crown gall Agrobacterium tumefaciens
 
Greasy center Pseudomonas viridiflava

Fungal diseases

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This also includes oomycetes

Disease Cause Image
Anthracnose Colletotrichum capsici
Anthracnose Colletotrichum dematium
Anthracnose Glomerella cingulata (Colletotrichum gloeosporioides anamorph)
 
Aerial blight Ceratobasidium ramicola (Rhizoctonia ramicola anamorph)
Basal stem and crown rot Sclerotinia sclerotiorum
 
Basal stem and root rot Ceratocystis sp.
 
Basal stem and root rot Thielaviopsis basicola anamorph / Chalara elegans synanamorph
 
Black rot Botryodiplodia sp.
 
Bract, flower and leaf blight Phytophthora drechsleri
Bract spot Corynespora cassiicola
 
Crown and stem rot Fusarium oxysporum
 
Crown and stem rot Nectria haematococca (Fusarium solani anamorph)
Cutting rot Cylindrocladium scoparium
 
Dieback Lasiodiplodia theobromae = Botryosphaeria theobromae
 
Gray mold Botryotinia ricini
Gray mold Amphobotrys ricini anamorph) = Botrytis ricini
Gray mold Botryotinia fuckeliana (Botrytis cinerea anamorph)
 
Leaf necrosis Cladosporium sp.
 
Leaf necrosis Macrophoma sp.
Leaf spot Alternaria euphorbiicola
Leaf spot Ascochyta sp.
 
Leaf spot Cercospora pulcherrima
Leaf spot Curvularia sp.
Leaf spot Drechslera sp.
Leaf spot Myrothecium roridum
Leaf spot Phyllosticta sp.
 
Leaf spot Syspastospora parasitica = Melanospora parasitica
Leaf spot Stemphylium sp.
 
Mushroom root rot Armillaria tabescens
 
Powdery mildew Oidium sp.
Powdery mildew Erysiphe sp.
 
Powdery mildew Microsphaera euphorbiae
Root rot Phytophthora nicotianae = Phytophthora nicotianae var. parasitica
 
Root rot Pythium aphanidermatum
Root rot Pythium debaryanum
Root rot Pythium myriotylum
Root rot Pythium perniciosum
Root rot Pythium splendens
 
Root rot Pythium ultimum
Root and stem rot Thanatephorus cucumeris (Rhizoctonia solani anamorph)
 
Rust Puccinia sp.
 
Rust Uromyces euphorbiae = Uromyces proëminens var. poinsettiae
Scab Sphaceloma poinsettiae
Stem gall Nectriella pironii (Kutilakesa pironii anamorph)
Stem rot Botryosphaeria ribis
Stem rot Diplodia sp.
 
Stem rot Leptothyrium sp.
Stem rot Phoma sp.
 
Stem rot Phomopsis sp.
 

Nematodes, parasitic

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Disease Cause Image
root-knot nematode Meloidogyne spp.
 

Viral and viroid diseases

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Disease Cause Image
mosaic Euphorbia mosaic virus
mosaic Poinsettia mosaic virus
(symptomless) Poinsettia latent virus

Miscellaneous diseases and disorders

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Miscellaneous diseases and disorders
Bleaching necrosis Air pollutant injury from either chlorides (> 0.5 ppm), nitrogen dioxide (> 2-3 ppm) or sulfur dioxide (> 0.5 ppm)
Bract necrosis Physiological disorder favored by high humidity, heavy watering and high (ammoniacal) fertility rates in the last 4 weeks of production
Chlorosis Nitrogen deficiency producing a general foliar yellowing

Molybdenum deficiency affecting mature young leaves and producing upward leaf roll
Sulfur deficiency causing young leaf yellowing
Zinc deficiency producing general yellowing and stunting of new leaves

Cyathia drop Response to low light conditions, dryness and/or high temperatures at the end of the production cycle
Dropping (epinasty) Ethylene toxicity (< 1 ppm) or low temperature chilling
Edema Physiological
Interveinal chlorosis Magnesium deficiency, initiating on older leaves

Manganese deficiency, initiating on young mature leaves
Ammonium toxicity produces V-shaped chlorotic bands starting at the leaf tip and accompanied by downward leaf cupping

Latex eruption High internal turgor pressure associated with certain cultivars, high humidity, high moisture availability, low temperatures and/or mechanical abrasion
Leaf glazing (bronzing) Peroxyacetyl nitrate (PAN) injury to the lower epidermis

(> 0.2 ppm)

Marginal necrosis Potassium deficiency

Fluoride toxicity on tips and margins of young leaves and bracts (0.4 ppm in water)
Lithium toxicity on older leaves (2 ppm)

Stem splitting Physiological expression of flower initiation
Stippling Ozone injury (> 4 ppm)
Terminal shoot necrosis Excessive soluble salts (> 800 EC X 102)
White bract Chilling injury occurring between 0–10 °C (32–50 °F)

References

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  • "Diseases of Poinsettia". Common Names of Diseases, The American Phytopathological Society]