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Send horticultural questions to ktilt@acesag.auburn.edu.
| PLANT | DISEASE | DESCRIPTION | CONTROL | |
| AGLAONEMA | Rhizoctonia Crown Rot | Brown dry decay of lower stem. | Sanitation; Cleary's 3336 protective treatments. | |
| BOXWOOD | Phytophthora Crown and Root Rot | Lower trunk is brown and rotted. Initially the decayed tissues are water-soaked but later the dead tissues are dried. | Sanitation. Improve soil drainage and/or decrease irrigation. See APMH for fungicides recommended for nursery situations and some large scale landscape plantings. | |
| CAMELLIA | Anthracnose (Colletotrichum) | Light to medium brown, circular-irregular (0.2-1 cm diam.) spots develop on leaves. | Sanitation; protective fungicides labelled on camellia such as Cleary's 3336. | |
| CAMELLIA | Botrytis (Sclerotinia) Flower Blight | Brown, small-large, irregularly-shaped lesions. | Sanitation of fallen blossoms; see APMH. | |
| CAMELLIA | Ring Spot Virus | Yellow rings appear on foliage; plants may become slightly stunted. | Sanitation. | |
| DUSTY MILLER | Alternaria Leaf Spot | Dark brown angular spots (0.2-0.6 cm) on foliage. | Sanitation; protective sprays of Cleary's will help. | |
| EUONYMUS | Anthracnose (Colletotrichum) | Large (1/4-1/2 inch diam.; 0.6-1.2 cm) brown, circular spots. | See APMH. | |
| EUONYMUS | Scab(Elsinoe) | Brown, raised, slightly corky spots (0.1-0.3 cm) develop on foliage. | Sanitation; Cleary's 3336 may help. | |
| GERANIUM | Oedema | Small (0.1-0.3 cm diam.), raised corky spots scattered on lower leaf surfaces. Upper leaf surfaces corresponding to corky spots often show yellowed spots. | Reduce watering schedules when weather is cloudy and cool. | |
| GERBERA DAISY | Powdery Mildew | Leaves show some necrosis and white powdery dusting on leaf surfaces. | Sanitation; Cleary's 3336. | |
| GERBERA DAISY | Phythium Root Rot | Plants become stunted and yellowed. Usually lower leaves become yellowed first. Roots become brown and water-soaked. | Sanitation of damaged plants. In some situations, removal of contaminated soil or media is recommended. Protective fungicide drenches in greenhouse situations. | |
| GREENHOUSE/ NURSERY CROPS | Peat Mold (Chromelosporium) | Tan-orange-yellow spore masses often develop on the surface of potting mix or at the edge of potting mix next to the pot rim. Extensive fungal growth may cause the potting media to become water repellent; that is, the media will not absorb water. | Sanitation. | |
| HOLLY, FOSTER | Bacterial Leaf Spot | Small, black, angular leaf spots. | Sanitation. | |
| HOLLY, JAPANESE | Phomopsis Dieback | Cankers on twigs and small branches with dieback resulting. | Sanitation. | |
| HYDRANGEA | Powdery Mildew | White dusty coating on upper leaf surfaces. Leaf yellowing and blight; some new growth distortions. | Sanitation. Fungicide spray treatments. See the APMH. | |
| HYDRANGEA | Phytophthora and Pythium Root Rot | Roots brown and water-soaked initially, then dried. | Sanitation; improve soil drainage and/or reduce irrigation; Banrot or Banol are recommended in some nursery situations. | |
| IMPATIENS | Impatiens Necrotic Spot Virus | Black, circular leaf spots; stunted growth. | Sanitation; thrips control. | |
| IMPATIENS | Phytophthora Crown Rot | Plants become stunted. Older leaves turn yellow. Roots become brown and water-soaked. | Sanitation of plants and sometimes removal of contaminated soil or media. Adjust watering practices and/or improve water drainage through soil or media. Fungicide drenches are often recommended in greenhouse situations. | |
| IMPATIENS | Pythium Crown Rot | See Phytophthora comments. | See Phytophthora comments. | |
| INDIAN HAWTHORNE | Entomosporium Leaf Spot | Red-black spots. | Sanitation. See the APMH. | |
| IVY, ENGLISH | Anthracnose (Colletorichum) | Black, irregularly shaped leaf spots. | Sanitation; see APMH. | |
| IVY, ENGLISH | Bacterial Leaf Spot (Xanthomonas) | Brown-black, angular, wet-looking spots (1/8 - 1/4 inch diam.; 0.3-0.6 cm). | Sanitation. See the APMH. | |
| IVY LEAF GERANIUM | Oedema | Upper leaf surface shows diffuse yellow spots; lower leaf surface shows brown, corky, slightly raised spots (less than 1/8 inch diam.; 0.1-0.3 cm). | Decrease watering schedule. | |
| KALANCHOE | Botrytis Blight | Brown, gray spots, blotches on the foliage. Infected areas may become limp. Spots look grayer when spore production occurs. | Sanitation. Apply protective fungicide drenhes. See APMH. Decrease humidity. Increase temperature. | |
| LANTANA | Foliar Leaf Spot Nematode | Angular, brown-black leaf spots. | Sanitation. | |
| LILY, EASTER | Lily Symptomless Virus & Cucumber Mosaic Virus | Yellow and brown flecks on foliage; plants stunted; leaves curl under. | Sanitation. Control aphids. | |
| MAGNOLIA | Algal Leaf Spot (Cephaleuros) | Greenish or reddish slightly raised spots (0.1-1 cm) on upper leaf surfaces. Spot edges are often irregular or wavy in appearance. Old spots are usually cream colored in the center. | Control measures are usually not necessary. Bordeaux mixture may be used. See the APMH. | |
| PANSY | Botrytis After Cold Damage | Brown leaf spots/blight; gray mold. | Sanitation; protective fungicide sprays. See the APMH. | |
| PANSY | Cercospora Leaf Spot | Brown-black circular spots. | Sanitation; Cleary's 3336. | |
| PANSY | Phytophthora Crown/Root Rot | See comments for Impatiens. | See comments for Impatiens. | |
| PANSY | Pythium Crown/Root Rot | See comments for Impatiens. | See comments for Impatiens. | |
| PHOTINIA | Entomosporium Leaf Spot | Small reddish spots (1/4-1/2 inch diam.; 0.6-1.2 cm) often coalesce into larger red spots with dark red centers and bright red, diffuse borders. | Sanitation; see APMH. | |
| PINE, LOBLOLLY | Needle Rust (Coleosporium) | Cream-white pustules (1/8 inch diam.; 0.2-0.3 cm) on needles. | No control recommended. | |
| PINE SEEDLINGS, LOBLOLLY | Phytophthora Root Rot | Plants become stunted. Older growth becomes yellowed. Roots become brown and water-soaked. | Sanitation of infected plants and sometimes media/soil replacement is recommended. Correct water problems. Fungicide drenches are recommended in nursery situations. | |
| PINE, VIRGINIA | LophodermiumPloioderma Needle Cast | Small (1.32-1/16 inch diam.; 0.15 cm or less; just barely visible), black, football-shaped slightly raised fruiting bodies scattered on needles; needles brown and drop. | See the APMH. | |
| poa trivialis | Pythium Blight | Foliage blight. | Decrease water content of soil. Apply fungicide treatments as listed in the APMH for turf grasses. | |
| POTHOS | Rhizoctonia Stem Rot | Stems near or touching the soil (potting mix) developed a dark brown canker or lesion (0.3-1 cm). | Sanitation. Protective sprays of Cleary's 3336 | |
| SNAPDRAGON | Root-Knot Nematode (Meloidogyne) | Stunted, wilted plants; roots develop irregular galls. | Sanitation; see APMH. | |
| SPIREA | Powdery Mildew | Leaves show a white powdery dusting on upper leaf surfaces and young shoots. | See APMH; sanitation. | |
| VERBENA | Bacterial Leaf Spot | Angular, water-soaked black or dark green leaf spots. | Sanitation. | |
| VERBENA | Myrothecium Crown Rot | Plants collapse after decay at crown. | Sanitation. | |
| VERBENA | Foliar Nematode | Angular brown leaf spots; sometimes these symptoms can be confused with bacterial disease. | Sanitation. | |
| VERBENA | Pythium Root Rot | Roots brown and water-soaked when infections are new. | Sanitation; improve water/soil situation so soil does not remain wet. |
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Send horticultural questions to ktilt@acesag.auburn.edu.