Fungal diseases
| Armillaria root rot
Shoestring root rot | Armillaria mellea
Rhizomorpha subcorticalis [anamorph] |
| Botryosphaeria dieback | Botryosphaeria dothidea
Fusicoccum aesculi [anamorph] |
| Botrytis leaf and petal blight | Botrytis cinerea
Botryotinia fuckeliana [teleomorph] |
| Bud and twig blight | Pycnostysanus azaleae
{{=}} Briosia azaleae |
| Cercospora leaf spot | Pseudocercospora handelii
{{=}} Cercospora handelii |
| Chrysomyxa leaf rust | Chrysomyxa ledi var. rhododendri
Chrysomyxa piperiana
Chrysomyxa roanensis |
| Clitocybe root rot (mushroom root rot) | Armillaria tabescens
{{=}} Clitocybe tabescens |
| Coryneum leaf spot | Seimatosporium rhododendri
{{=}} Coryneum rhododendri |
| Cryptostictis leaf spot | Seimatosporium mariae
{{=}} Cryptostictis mariae |
| Cylindrocarpon canker and wilt | Cylindrocarpon destructans
{{=}} Cylindrocarpon radicicola |
| Damping-off, Pythium | Pythium spp. |
| Damping-off, Rhizoctonia | Rhizoctonia solani
Thanatephorus cucumeris [teleomorph] |
| Exobasidium leaf spot | Exobasidium burtii |
| Glomerella canker and dieback | Glomerella cingulata
Colletotrichum gloeosporioides [anamorph] |
| Gray blight | Pestalotia sydowiana |
| Leaf and flower gall | Exobasidium vaccinii
{{=}} Exobasidium azaleae |
| Lophodermium leaf spot | Lophodermium schweinitzii |
| Ovulinia petal blight | Ovulinia azaleae
Ovulitis azaleae [anamorph] |
| Pestalosphaeria leaf spot | Pestalosphaeria concentrica
Pestalotiopsis guepini [anamorph] |
| Pestalotia leaf spot | Pestalotiopsis sydowiana
{{=}} Pestalotia rhododendri |
| Phymatotrichum root rot (cotton root rot) | Phymatotrichopsis omnivora
{{=}} Phymatotrichum omnivorum |
| Phytophthora dieback | Phytophthora nicotianae var. parasitica
{{=}} Phytophthora parasitica
Phytophthora cactorum
Phytophthora cinnamomi
Phytophthora citricola
Phytophthora citrophthora
Phytophthora heveae
Phytophthora lateralis |
| Phytophthora root rot | Phytophthora cactorum
Phytophthora cinnamomi
Phytophthora citricola |
| Powdery mildew | Microsphaera vaccinii
{{=}} Microsphaera penicillata var. vaccinii |
| Pucciniastrum leaf rust | Pucciniastrum vaccinii |
| Septoria leaf spot | Septoria rhododendri |
| Spot anthracnose | Sphaceloma sp. |
| Stem canker | Cylindrocladium theae
Calonectria theae [teleomorph] |
| Witches' broom | Exobasidium vaccinii-uliginosi |
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