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Send horticultural questions to ktilt@acesag.auburn.edu.
| PLANT | DISEASE | DESCRIPTION | CONTROL | |
| ARBOR-VITAE | Phytophthora Root Rot | Roots become brown, decayed. When disease is active, roots are water-soaked. | Sanitation; protective fungicide drenches. See APMH. | |
| AZALEA | Powdery Mildew (Microsphaeria) | Whitish powdery dusting on leaves; some leaf deformity if infection occurs on new growth; infected leaves eventually become yellowed. | See the APMH. | |
| AZALEA (Cuttings, Liners) | Aerial Web Blight (Rhizoctonia) | Lower leaves become brown spotted or blighted; when conditions are humid, a delicate mycelial webbing may occur on infected leaves, eventually, infected, blighted leaves drop. | See the APMH. | |
| AZALEA | Phytophthora Root Rot | See Arbor-vitae. | See Arbor-vitae comments. | |
| AZALEA (Cutting) | Rhizoctonia Cutting End Rot. | Cutting ends develop brown lesions which may completely encircle the stem. Plant death results. | Sanitation. | |
| BOXWOOD | Nectria cinnabarina Canker | Sunken lesions on branches, sometimes with orange pin-point bodies of he fungus; dieback. | Pruning at least 3 inches beyond the canker edge. | |
| CAMELLIA | Phyllosticta Leaf Spot | Dark purple-brown circular-oval leaf spots. | Sanitation in the fall. Protective fungicide sprays (Cleary's 3336) if disease appears early in the season. | |
| CHRYSANTHEMUM | Pythium Root Rot | Roots brown and water-soaked. Foliage yellows and shows poor growth, dies. | Sanitation; protective fungicide drench treatments; see APMH. | |
| DIANTHUS | Bacterial Leaf Spot (Xanthomonas) | Small, black, angular, wet-looking spot. | Sanitation; Kocide may help. | |
| DIANTHUS | Colletotrichum Leaf Spot | Irregular brown, sometimes circular spots. | Sanitation; protective sprays of Cleary's will help. | |
| GARDENIA | Phytophthora Root Rot | Brown, discolored, decayed, water-soaked roots. | Sanitation; reduce soil moisture; Banrot or Banol may be used - usually in a nursery situation. | |
| GERANIUM | Oedema | Corky brown spots (2-3 mm) on lower leaf surfaces. Corresponding upper leaf surfaces become yellow spotted. | Reduce watering schedule when weather is cool and cloudy. | |
| HELLERI HOLLY liners and containers | Black Root Rot (Thielaviopsis) | Roots develop black tips and black lesions and sections. | Sanitation; see APMH. | |
| HELLERI HOLLY liners and containers | Rhizoctonia Aerial Blight | Lower leaves become spotted and blighted. Leaf fall occurs. | See APMH. | |
| HOLLY, COMPACTA AND HELLERI | Phytopthora Root Rot | Feeder and major roots show a brown, wet decay. The outer cortex can be easily slipped off of the inner central root cylinder. | Sanitation; see the APMH. | |
| HOLLY, COMPACTA AND HELLERI | Colletotrichum Leaf Spot | Brown-black circular spots. | Sanitation. Cleary's 3336 may be used as a protective treatment. | |
| INDIAN HAWTHORNE | Entomosporium Leaf Spot | Black spots with red borders develop on the foliage. | Sanitation; protective fungicide sprays. See the APMH. | |
| IVY, ENGLISH | Nectria Canker | Sunken lesions on branches/stems; sometimes diagnostic red pin-point fruiting bodies are present. | Pruning lesions making cuts at least 3 inhes beyond lesions edges. Cleary's may help. | |
| JUNIPER | Phomopsis Tip blight | Dieback. | Sanitation. See the APMH. | |
| JUNIPER | Phytophthora Root Rot | See Arbor-vitae. | See Arbor-vitae comments. | |
| KALANCHOE | Powdery Mildew (Sphaerotheca) | Leaves and stems are covered with a white powdery dusting. Some distortion of new growth may be present. Some foliage yellowing and browning may be present. | Sanitation. Maintain even day-night temperatures if possible. Apply protective sprays of a recommended fungicide. See APMH. | |
| LUPIN | Rhizoctonia Root Rot | Roots become brown and dried. | -- | |
| LUPIN | Pythium Root Rot/Seedling Disease | Roots become brown and watersoaked. | -- | |
| MAGNOLIA, SOUTHERN | Algal Leaf Spot (Cephaleuros) | Green or reddish-colored, slightly raised, usually circular or oval spots with wavy margins develop on upper leaf surfaces. | Sanitation. | |
| MARIGOLD Plugs | Alternaria Leaf Spot | Small, dark brown, irregular spots (1-3 mm) on leaves and stems. | See APMH. | |
| OAK | Ganoderma Wood/Root Rot | Tree dieback. Conks developing on the trunks of infected trees are non-gilled, poroid, with or without a lateral stalk, with a distinctive reddish-brown or gray-brown varnish-like crust on the upper surface. | Sanitation. Remove wet conditions. | |
| PANSY | Anthracnose (Colletotrichum) | Small, cream-colored, circular spots with dark borders. | Sanitation. See the APMH. | |
| PANSY | Black Root Rot (Thielaviopsis) | Black root tips and black root lesions and areas. | Cleary's 3336; see APMH. | |
| PANSY | Cercospora Leaf Spot | Gray-black round leaf spots about 1/4-1/2 cm. | Sanitation. Daconil or Cleary's 3336 may be used for protective disease control. | |
| PANSY | Myrothecium Crown Rot | Collapse of petioles or lower stems. Tiny black and white pinhead sized bodies on collapsed tissues. | Sanitation. Daconil protective sprays. | |
| PANSY | Phytophthora Crown Rot | Crowns, roots become brown and watersoaked. | Sanitation. See the APMH. | |
| PANSY | Pythium Crown/Root Rot | Crowns, roots become brown and watersoaked. | See the APMH. | |
| PERIWINKLE | Rhizoctonia Crown Rot | Crowns, roots become dried, brown, rotted. | Sanitation; see APMH. | |
| PHLOX | Black Root Rot (Thielaviopsis) | See Pansy. | See Pansy. | |
| PHOTINIA | Entomosporium Leaf Spot | Black spots with dark red borders; spot coalescence; leaf drop. | Sanitation; Cleary's 3336 protective drenches. | |
| PINE, VIRGINIA | Ploioderma (Lophodermium)Needle Cast | Older needles become yellow and then brown in spots; eventually whole needles turn brown and drop. Small, black football shaped lesions (1-2 mm long) develop on brown needles. | Protective fungicide sprays. See the APMH. | |
| PINE, VIRGINIA | Fusarium Pitch Canker | Elongated cankers. Some resin flow. | Sanitation. See comments in the APMH. | |
| PINE, VIRGINIA | Rhizosphaeria Needle Cast | Needles turn brown. Tiny black dots (fruiting bodies) occur in a linear arrangement on browning needles. | -- | |
| POINSETTIA | Phytophthora Root Rot | See Pythium Root Rot. | See Pythium Root Rot. | |
| POINSETTIA | Pythium Stem and Root Rot | Lower stem and roots become brown, soft, water-soaked, and rotted. | See APMH; sanitation. | |
| POINSETTIA | Botrytis Blight | Bracts and leaves develop gray lesions and areas. Elongated lesions may occur on stems. A gray web may develop on suface of lesions when conditions are humid. | See APMH. | |
| POINSETTIA | Rhizoctonia Crown Rot and Root Rot | Lower stems develop dry, medium-dark brown surface lesions; roots may become brown and dried. | See See APMH; sanitation. | |
| ROSE, Miniature | Phytophthora Root Rot | Brown, water-soaked dying roots. | Sanitation. |
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Send horticultural questions to ktilt@acesag.auburn.edu.