This article is a list of diseases of lettuce (Lactuca sativa).
| Bacterial diseases | |
|---|---|
| Bacterial leaf spot and head rot | Xanthomonas campestris pv. vitians |
| Bacterial soft rot | Erwinia carotovora Pseudomonas marginalis |
| Corky root | Rhizomonas spp. R. suberifaciens |
| Varnish spot | Pseudomonas cichorii |
| Fungal diseases | |
|---|---|
| Alternaria leaf spot | Alternaria sonchi |
| Anthracnose | Microdochium panattonianum Marssonina panattoniana |
| Bottom rot | Rhizoctonia solani Thanatephorus cucumeris [teleomorph] |
| Cercospora leaf spot | Cercospora longissima |
| Damping-off, Pythium | Pythium spp. Pythium ultimum |
| Damping-off, Rhizoctonia | Rhizoctonia solani |
| Downy mildew | Bremia lactucae Plasmopara lactucae-radicis |
| Drop (Sclerotinia rot) | Sclerotinia sclerotiorum Sclerotinia minor |
| Gray mold | Botrytis cinerea Botryotinia fuckeliana [teleomorph] |
| Phymatotrichum root rot (cotton root rot) | Phymatotrichopsis omnivora Phymatotrichum omnivorum |
| Powdery mildew | Erysiphe cichoracearum |
| Rust | Puccinia dioicae Puccinia extensicola var. hieraciata |
| Septoria leaf spot | Septoria lactucae |
| Southern blight | Sclerotium rolfsii Athelia rolfsii [teleomorph] |
| Stemphylium leaf spot | Stemphylium botryosum Pleospora tarda [teleomorph] |
| Wilt and leaf blight | Pythium tracheiphilum |
| Miscellaneous diseases and disorders | |
|---|---|
| Brown stain | Physiological, excess CO2 |
| Russet spotting | Physiological, excess ethylene |
| Tipburn | Physiological, Ca** deficiency and high temperature |
| Nematodes, parasitic | |
|---|---|
| False root knot | Nacobbus aberrans |
| Lesion | Pratylenchus spp. |
| Needle | Longidorus spp. |
| Root-knot | Meloidogyne spp. |
| Spiral | Rotylenchus robustus |
| Stunt | Melinius brevidens Tylenchorhynchus spp. |
| Viral and viroid diseases | |
|---|---|
| Big vein | |
| Calico | |
| Lettuce dieback[1] | |
| Internal rib necrosis | |
| Mosaic | |
| Necrotic yellows | |
| Ring necrosis | Presumed viral agent (not identified) |
| Rusty brown discoloration | |
| Speckles | Lettuce speckles virus and beet western yellows virus |
| Stunt | |
| Virescence | Aster yellows phytoplasma Beet leafhopper-transmitted virescence phytoplasma |
| Wilt | |
| Yellow spot | |
| Yellows | |
| Other | |