This article is a list of diseases of azalea (Rhododendron spp.).

Fungal diseases

Fungal diseasesAnthracnose Glomerella cingulata Colletotrichum gloeosporioides [anamorph] Armillaria root rot (shoestring root rot) Armillaria mellea Rhizomorpha subcorticalis [anamorph] Botrytis petal blight Botrytis cinereaBotryotinia fuckeliana [teleomorph] Bud and twig blight Pycnostysanus azaleae = Briosia azaleaeCercospora leaf spot Pseudocercospora handelii = Cercospora handeliiClitocybe root rot (mushroom root rot) Armillaria tabescens = Clitocybe tabescensCylindrocladium blight and root rot Cylindrocladium scoparium = Cylindrocladium floridanum Calonectria kyotensis [teleomorph] Cylindrocladium theae Calonectria theae [teleomorph] Damping-off, Pythium Pythium spp. Pythium irregulareDamping-off, Rhizoctonia Rhizoctonia solani Thanatephorus cucumeris [teleomorph] Exobasidium leaf spot Exobasidium burtiiLeaf scorch Septoria azaleaeLeaf and flower gall Exobasidium vaccinii = Exobasidium azaleaeOvulinia petal blight Ovulinia azaleae Ovulitis azaleae [anamorph] Pestalotia leaf spot twig blight, and crown rot Pestalotiopsis sydowiana = Pestalotia rhododendriPhomopsis dieback Phomopsis spp. Phyllosticta leaf spot Phyllosticta spp. Phytophthora blight and dieback Phytophthora nicotianae var. parasitica = Phytophthora parasiticaPhytophthora root rot and wilt Phytophthora cinnamomi Phytophthora nicotianae var. parasiticaPowdery mildew Erysiphe polygoni Microsphaera penicillataPucciniastrum leaf rust Pucciniastrum vacciniiTwig blight Monilinia azaleaeWeb blight Rhizoctonia ramicola Ceratobasidium ramicola [teleomorph] Rhizoctonia sp. (binucleate)

Nematodes, parasitic

Nematodes, parasiticDagger, American Xiphinema americanumPin Paratylenchus curvitatusRoot-knot Meloidogyne spp. Sheath Hemicycliophora spp. Spiral Rotylenchus buxophilus R. robustusStubby-root Paratrichodorus minorStunt Tylenchorhynchus claytoni

References Common Names of Diseases, The American Phytopathological Society