# List of poinsettia diseases

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

## Bacterial diseases

| Disease | Cause |
| 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

This also includes oomycetes
| Disease | Cause |
| 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

| Disease | Cause | Image |
| root-knot nematode | Meloidogyne spp. | |

## Viral and viroid diseases

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

## Miscellaneous diseases and disorders

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) |