List of poinsettia diseases

Poinsettia growing in Barlovento, Canary Islands

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

Bacterial diseases[]

Disease	Cause	Image
Bacterial leaf spot	Curtobacterium flaccumfaciens =
Bacterial leaf spot	Pseudomonas cichorii
Bacterial leaf spot	Pseudomonas marginalis
Bacterial leaf spot
Bacterial leaf spot

	Erwinia chrysanthemi
Crown gall	Agrobacterium tumefaciens
	Pseudomonas viridiflava

Fungal diseases[]

This also includes oomycetes

Disease	Cause	Image
Anthracnose	Colletotrichum capsici
Anthracnose	Colletotrichum dematium
Anthracnose	Glomerella cingulata (Colletotrichum gloeosporioides anamorph)
	Ceratobasidium ramicola (Rhizoctonia ramicola anamorph)
	Sclerotinia sclerotiorum
	Ceratocystis sp.
	Thielaviopsis basicola anamorph / Chalara elegans synanamorph
Black rot	sp.
	Phytophthora drechsleri
	Corynespora cassiicola
	Fusarium oxysporum
	Nectria haematococca (Fusarium solani anamorph)
	Cylindrocladium scoparium
Dieback	Lasiodiplodia theobromae =
Gray mold	Botryotinia ricini
Gray mold	Amphobotrys ricini anamorph) = Botrytis ricini
Gray mold	Botryotinia fuckeliana (Botrytis cinerea anamorph)
	Cladosporium sp.
	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.
	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
	Thanatephorus cucumeris (Rhizoctonia solani anamorph)
Rust	Puccinia sp.
Rust	Uromyces euphorbiae = Uromyces proëminens var. poinsettiae
Scab	Sphaceloma poinsettiae
	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[]

Disease	Cause	Image
root-knot nematode	Meloidogyne spp.

Viral and viroid diseases[]

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

Miscellaneous diseases and disorders[]

Miscellaneous diseases and disorders
	Air pollutant injury from either chlorides (> 0.5 ppm), nitrogen dioxide (> 2-3 ppm) or sulfur dioxide (> 0.5 ppm)
	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
	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
	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
	High internal turgor pressure associated with certain cultivars, high humidity, high moisture availability, low temperatures and/or mechanical abrasion
(bronzing)	Peroxyacetyl nitrate (PAN) injury to the lower epidermis (> 0.2 ppm)
	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)
	Physiological expression of flower initiation
Stippling	Ozone injury (> 4 ppm)
	Excessive soluble salts (> 800 EC X 102)
	Chilling injury occurring between 0–10 °C (32–50 °F)

References[]

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