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Send horticultural questions to ktilt@acesag.auburn.edu.
| PLANT | DISEASE | DESCRIPTION | CONTROL |
| ASH | Anthracnose (Apiognomonia) | Irregular brown blotches of variable sizes occur along leaf edges and along leaf veins mostly. | Sanitation. |
| ASTER | Southern Blight Sclerotium | Decay of stem at soil line; white mycelium (sometimes with brown-black mustard-seed-sized sclerotia may be present) often at soil line. | Soil solarization. |
| AUCUBA | Botryiodiplodia Canker/Dieback | Black cankers on stems. | Pruning; Cleary's 3336. |
| AZALEA | Bacterial Leaf Spot | Black irregular spots; water soaked spot edges. | Strict sanitation. Do not water over-head. |
| AZALEA | Colletotrichum Leaf Spot | Small, circular brown leaf spots. | Sanitation; protective sprays of Cleary's 3336. |
| AZALEA | Phytophthora Root Crown/Rot) | Brown, water-soaked areas on crown and roots; outer root cortex slips easily away from inner tissues. | Sanitation; good drainage; fungicide drenches. |
| AZALEA | Phomopsis Dieback (Stress-related) | Sunken cankers that cause dieback of individual branches. | Pruning; eliminate stress. |
| BEGONIA | Pythium Root Rot | Roots become soft, brown and water-soaked. | Sanitation. See the APMH. |
| BEGONIA | Rhizoctonia Aerial Blight | Leaves become brown spotted, blighted and shredded. | Cleary's 3336, Domain, benomyl products labelled for ornamentals; sanitation. |
| CHRYSANTHEMUM | Bacterial Leaf Spot | Angular, small, black leaf spots. | See the APMH. |
| CRABAPPLE | Cedar-Apple Rust (Gymnosporangium) | Large (3-5 mm), bright yellow spots; on underside of leaf spots, orange pustules may be present. | See APMH. |
| DAYLILY | Southern Blight Sclerotium rolfsii) | Crown rot; white mold at crown. | Sanitation; rotation to turf; solarization.. |
| DELPHINIUM | Fusarium Root Rot | Roots become brown and dried. | Crop rotate away from Delphinium, Zinnia. |
| DOGWOOD | Botrytis Leaf Spot/Blight | Brown-gray leaf spots/blotches. | Cleary's, Domain. |
| DOGWOOD | Cercospora & Seporia Leaf Spots | Round-angular, brown spots (2-4 mm). | Sanitation; See APMH. |
| DOGWOOD | Spot Anthracnose (Elsinoe) | Tiny red spots on bracts and leaves. | See APMH. |
| FERN | Pythium Root Rot | Brown, watersoaked roots. | See APMH. |
| GERANIUM | Botrytis Blight | Blossoms become gray-brown and limp. | Sanitation; see the APMH. |
| GERANIUM | Phytophthora Root Rot | Roots become brown, water-soaked. | See the APMH. |
| GERANIUM | Xanthomonas campestris pv pelargonii | Leaves develop black spots. Stems develop black rot areas. The bacerial infection will become systemic and eventually plants will wilt. | Sanitation. |
| HAWTHORNE | Cedar-Hawthorne Rust | Bright yellow spots on leaves and fruit of apple, crabapple, hawthorne. Aecial orange cups develop in spots. (Cedars develop cankers). | See ANR-468. |
| HIBISCUS | Fusarium Stem/Root Rot | Dark brown, dry stem decay lesion. | Sanitation. Protective treatment spray of Cleary's 3336. |
| HYDRANGEA | Cercospora Leaf Spot | Irregular brown lesions of variable sizes develop on leaves. | Sanitation; Cleary's 3336 or Domain protective sprays. |
| IMPATIENS | Impatiens Necrotic Spot Virus | New growth is dwarfed and stunted; foliage may show yellowing spots/patterns or black spots/patterns. | Sanitation; Thrips control with insecticides. |
| IMPATIENS | Phytophthora Crown & Root Rot | Medium brown, wet, soft rot of lower stem and roots. | Sanitation; see APMH. |
| IMPATIENS | Pythium Root Rot | Medium brown, wet, soft rot of lower stem and roots. | Sanitation; see the APMH. |
| IMPATIENS | Rhizoctonia Crown Rot | Dark brown, dried crown/rot. | Sanitation; See the APMH. |
| IVY, ENGLISH | Alternaria Leaf Spot | Large, brown-black, sometimes zonate, circular-oval spots (3-5 mm diam.). | See the APMH. |
| IVY, ENGLISH | Bacterial Leaf Spot | Angular, black, water-soaked spots (2-3 mm diam.). | Sanitation; see the APMH. |
| IVY, ENGLISH | Phyllosticta Leaf Spot | Brown, circular to oval leaf spots. | See recommendations for Alternaria. |
| IVY, ENGLISH | Phytophthora Root Rot | Brown, water-soaked root decay. | Sanitation; see the APMH. |
| JUNIPER | Phytophthora Root Rot | Roots become brown, soft, and water-soaked. | Sanitation. See the APMH. |
| JUNIPER | Twig Blight (Phomopsis) | Brown twig tips; small cankers at base of small twigs. | Sanitation. Cleary's 3336, Domain, or a benomyl fungicide labelled for ornamentals. |
| LIGUSTRUM | Colletortrichum Leaf Spot | Medium brown circular-irregular leaf spots. | Sanitation. See APMH. |
| LILAC | Phytophthora Root Rot | Roots become brown and water-soaked. | Subdue 2E may be used as a protective treatment. First test a few plants to be sure phytotoxicity is not a problem. |
| LIRIOPE | Colletotrichum Leaf Spot | Brown, circular-irregular leaf spots (2-10 mm diam). When spots coalesce, a large portion of leaf may turn brown and die. Often leaf tips are affected. | Sanitation; Cleary's 3336, Domain, or a benomyl fungicide labelled for ornamentals. |
| MAGNOLIA, JAPANESE | Bacterial Leaf Spot | Brown, irregular leaf spots with water-soaked margins. | Strict sanitation. |
| MAPLE | Anthracnose (Kabatiella) | Large, light-brown irregular spots and blotches may kill whole leaves; spots often follow leaf veins. | Sanitation; fungicide sprays. |
| MAPLE | Phyllosticta Leaf Spot | Spots are circular-irregular, and have brown centers with purple margins (1/8" - 1/2" diam). | Sanitation; fungicide sprays. |
| MAPLE | Ganoderma Wood/Wood Rot | Dieback; brown wood rot. | Sanitation. |
| OAK | Anthracnose(Apiognomonia) | Brown blotches often along leaf veins or leaf edges. | Sanitation; See APMH for small oak trees. |
| OAK | Oak Leaf Blister(Taphrina) | Round, slightly convex-concave light brown leaf spots (4-5 mm diam). | Sanitation; See APMH for small oak trees. |
| OAK | Phyllosticta Leaf Spot | Circular, brown spots (2-4 mm diam). | Sanitation. |
| OAK | Slime Flux | A foul smelling ooze runs down trunk surface. Initial infection of fungi, bacteria, and yeast develops in wound area. | Sanitation of infection area when it is still localized. |
| PAMPAS GRASS | Piricularia Leaf Spot | Gray-brown circular leaf spots. | Cleary's 3336. |
| PERIWINKLE | Anthracnose (Colletotrichum) | Brown, sunken cankers on stem sections. | Cleary's 3336, Domain, or WP benomyl; Sanitation. |
| PERIWINKLE | Phomopsis Blight | Brown, sunken cankers on stem sections. | Cleary's, Domain or WP benomyl; Sanitation. |
| PERIWINKLE | Phytophthora Aerial Blight | Dark brown, black cankers encircle stems and cause wilt and disback. | Sanitation. |
| PERIWINKLE | Rhizoctonia Aerial Blight/ Crown Rot | Lower leaves and lower stem near the soil line become browned and decayed. | See APMH; Sanitation. |
| PETUNIA | Phytophthora Foliage Blight/Root Rot | Foliage develops spots, blight, collapse. | Sanitation. |
| PHOTINIA | Bacterial Leaf Spot | Brown, irregular leaf spots with water-soaked edges. | strict sanitation. |
| PHOTINIA | Entomosporium Leaf Spot | Red-black circular leaf spots. | See APMH. |
| PINE, VIRGINIA | Pitch Canker Fusarium | Sunken lesions on branches/trunk with resin flow. | Sanitation. |
| PINE, LOBLOLLY | Pythium Root Rot | Brown, water-soaked roots. | See APMH. |
| POINSETTIA | Pythium Root Rot | Roots become soft, brown, water-soaked. | See the APMH. |
| PYRACANTHA | Southern Blight (Sclerotium) | See Aster. | Solarization. |
| RHODODENDRON | Botryosphaeria Canker | Sunken, brown, dried, cracked, elliptical lesions develop on branches. | Sanitation. Protective spray of Cleary's 3336 or Domain. |
| ROSE | Cercospora rosicola Leaf Spot | Circular brown spots. | See APMH for black spot. |
| SNAPDRAGON | Phytophthora Root Rot | Roots become brown and watersoaked. | See APMH. |
| SYCAMORE | Powdery Mildew | White powdery substance on leaves. | See APMH. |
| SYCAMORE | Scorch (Xylella) | Leaves become brown and dried at the margins. | Tree pruning; tree removal. |
| VERBENA | Fusarium Crown Rot | Brown, lower stem rot. | Cleary's drenches may help. |
| VINCA MINOR | Anthracnose Colletotrichum) | Brown, irregular spots develop leaves. | Sanitation. Cleary's 3336, Domain or a benomyl product labelled for ornamentals. |
| VINCA MINOR | Pythium Root Rot | Roots become brown and water-soaked. | Aliette protective treatments or Subdue 2E. (Test a few plants for phytotoxicity). |
| VINCA MINOR | Rhizoctonia Stem Blight | Brown lesions near soil line. | Sanitation. Cleary's 3336 or benomyl protective sprays. |
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Send horticultural questions to ktilt@acesag.auburn.edu.