DISEASE DESCRIPTIONS AND BRIEF CONTROL COMMMENTS ON
SOME COMMON DISEASES OFTEN SEEN IN SEPTEMBER


(APMH = The Alabama Pest Management Handbook).

.
PLANT DISEASE DESCRIPTION CONTROL
AUCUBA Lasiodiplodia Canker Black sunken spots or sunken areas on aucuba stems. Dieback of foliage results. Cleary's 3336, or Domain protective sprays labelled for ornamentals; sanitation.
AZALEA Cercospora Leaf Spot Small dark brown-black, usually circular spots (1-2 mm) scattered over leaf surface. Sanitation and Cleary's 3336 protective sprays.
AZALEA Phytophthora Crown and Root Rot Lower stem near soil and roots become brown and water-soaked. Sanitation and proper soil or potting mix drainage are important. See APMH and/or ANR-571.
AZALEA Rhizoctonia Aerial Blight Brown, irregular spots and lesions begin on lower leaves. Whole leaves may become blighted; leaf drop occurs. Sanitation; See APMH.
BEGONIA Phytophthora Crown Rot Crown tissues are dark and wet-rotted. Sanitation. Reduce watering.
BEGONIA Phytophthora & Pythium RootRot Roots become brown and water-soaked, decayed. Sanitation. Reduce watering. See the APMH.
BEGONIA Rhizoctonia Root Rot Brown, dry, decayed roots. Sanitation. Banrot protective drenches.
BEGONIARoot-Knot Nematode (Meloidogyne) Galls on roots; plants stunted and wilted. Solarization.
BEGONIA Tomato Spotted Wilt Virus Yellow mosaic and ring spots present. Sometimes brown spots also present. Thrips control. Sanitation.
BOXWOOD Phytophthora Root Rot Brown, water-soaked roots. See APMH.
CELOSIA Phytophthora, Pythium, Fusarium Lower Stem Rot & Root Rot Roots brown and decayed. Sanitation. Reduce watering. Improve soil drainage.
CHERRY Septoria Leaf Spot Small (0.5 cm or less in diam.), angular brown spots. Sanitation in the fall.
CLEYERA Phytophthora Root Rot See Boxwood. Sanitation. Improve soil drainage.
CYPRESS, LEYLAND Cercospora (Cercosporella) Blight Needle and twig blight that usually begins on lower foliage. Sanitation. Cleary's 3336 protective sprays.
DOGWOOD Botryosphaeria Canker Slightly sunken lesion, sometimes with cracks along the margin. Sanitation.
DOGWOOD Cercospora Leaf Spot Angular-irregular tan-brown lesions (2-6 mm diam.) sometimes with a thin yellow halo. Usually sanitation is the only control measure needed.
DOGWOOD Septoria Leaf Spot Angular, brown spots, about 1 cm or less in diam; may be confused with Cercospora leaf spot. Collect and remove fallen leaves this fall.
DUSTY MILLER Alternaria Leaf Spot Dark, angular spots. Sanitation; Cleary's 3336.
ELEAGNUS Phytophthora Root Rot Brown, wet root decay. Sanitation. Improve soil drainage.
EUONYMUS Anthracnose (Colletotrichum) Small brown spots (about 5 mm or smaller) on foliage. Sanitation; See the APMH for protective fungicide recommendations.
FERN Anthracnose (Colletotrichum) Gray-brown irregular blotches on fronds. Orange spore masses may be present in humid weather. Sanitation; See the APMH under leaf spot.
FERN Rhizoctonia Aerial Blight Gray or brown irregular blotches on fronds; some 'shot-hole'. Sanitation; See the APMH.
GARDENIA Phytophthora Crown Rot Lower stem/trunk at the soil line develops wet decay. Sanitation. (See the APMH under Root Rot for protective treatment.)
HICKORY Scab (Cladosporium) Small, dark brown, slightly raised leaf spots. Sanitation in the fall.
HOLLY, BLUE MAID Botryosphaeria Canker Brown or black sunken, cracked lesions (cankers) on branches. Sanitation. Protective sprays of Cleary's 3336, Domain or a WP benomyl labelled for ornamentals.
HOLLY, BLUE MAID Phytophthora Root Rot Feeder roots become water-soaked, decayed. See the APMH.
HYDRANGEA Cercospora Leaf Spot Relatively large (0.5-1.0 cm) dark brown circular spots with reddish borders. Sanitation. See the APMH.
HYDRANGEA Phytophthora & Pythium Root Rot Roots become brown and water-soaked. Sanitation. See the APMH.
IMPATIENS Alternaria Leaf Spot Small circular or angular dark brown spots. Sanitation; a mancozeb product such as Duosan or Zyban.
IRIS Bacterial Soft Rot Soft, wet, watery rot of rhizome. Sanitation. Control insect problems.
IRIS Fusarium Rhizome Rot Areas of the rhizome exhibit a dry, brown rot. Sanitation. See the APMH.
IVY, ENGLISH Phytophthora Crown & Root Rot Tissues dark and water-soaked. Sanitation; reduce irrigation or improve drainage.
JUNIPER Phomopsis Dieback Juniper branch tips become brown. Cankers develop on twigs and dieback continues down the twig. See the APMH.
JUNIPER Phytophthora Root Rot See Holly..
LIGUSTRUM Cercospora Leaf Spot Brown irregular spots (about 1 cm diam.) on foliage; when leaf spot is severe, defoliation may result. Sanitation; See the APMH.
LIRIOPE Anthracnose (Colletotrichum) Brown irregular blotches on leaf blades; often, leaf tip areas are involved. Sanitation; See the APMH.
LORIPETALUM Pythium Root Rot Light brown, water-soaked, rotted roots. Sanitation. Reduce irrigation or improve soil drainage.
MAPLE Anthracnose (Kabatiella) Brown spots and blotches on foliage; enlarged spots may involve more than half of individual leaves. Sanitation. See the APMH.
MAPLE Phyllosticta Leaf Spot Gray circular spots ( inch diam., approx.) with dark brown or reddish brown borders. Sanitation.
MARIGOLD Alternaria Leaf Spot Small (0.2-0.3 cm diam.) dark brown-black spots. Numerous spots cause death of plants. Sanitation. See the APMH.
OAK Powdery Mildew (Microsphaera) White dusty coating on upper leaf surfaces. Some distortion of new leaves. Collect and remove fallen leaves this fall.
OAK, PIN Xylella Scorch Lower and oldest leaves show leaf edge scorch; problem progresses upward through the tree canopy. Dieback develops; eventual tree death. Remove dying trees.
PANSY Anthracnose (Colletotrichum) Small, round, light brown, cream-colored spots. Sanitation. Cleary's 3336.
PANSY Myrothecium Crown Rot Dieback; decayed crowns. Sanitation; See A. Hagan.
PANSY Phytophthora & Pythium Root Rot Brown, wet-rotted roots. Sanitation. See APMH.
PANSY Phyllosticta Leaf Spot Relatively small (2-3 mm diam.) medium brown, roughly circular spots. Spot centers may become gray. Sanitation. Protective sprays of Cleary's 3336, Domain, or a benomyl WP labelled for ornamentals.
PANSY Phytophthora Root Rot Roots become brown and water-soaked. Sanitation. See the APMH.
PANSY Pythium Root Rot Roots become brown and water-soaked. Sanitation; See the APMH.
PANSY Thielaviopsis Root Rot Roots become covered with black spots/ lesions. Sanitation; Cleary's, or Domain protective drenches.
PEAR, BRADFORD Fabraea Leaf Spot Black circular spots (about 0.2-0.4 cm diam.) Sanitation of fallen leaves in the fall. Regular spray schedule may help.
PETUNIA Phytophthora Root Rot Roots water-soaked, decayed. Sanitation
PHOTINIA Armillaria Root Rot Plant may decline slowly or suddenly; lower trunk under the bark and roots may be covered with closely appressed white fungal mat with black, threadlike structures. Sanitation. See PP-145.
PHOTINIA Phytophthora Root Rot See Azalea..
PINE, VIRGINIA Lophodermium (Ploioderma) Needle Cast Older needles turn brown and drop; very small (1-2 mm or 1/32 inch) football shaped, black fruiting bodies develop on brown needles. Protective fungicides spray. See APMH.
PINE, VIRGINIA Rhizosphaeria Needle Cast Needles become gray-brown. Twig blight may develop. Sanitation. See the APMH.
PITTOSPORUM Southern Blight (Sclerotium rolfsii) Lower trunk becomes rotted and softened. White mycelial mats and tiny black spherical bodies (sclerotia) may be present on trunk at soil surface. Sanitation.
POINSETTIA Rhizoctonia Stem Rot & Root Rot Lower stems develops dry medium-dark brown surface lesions; roots may become brown and dried. See APMH.
POINSETTIA Pythium Root Rot Roots become medium brown, soft, water-soaked and rotted. See APMH.
POINSETTIA Rhizopus Stem Rot Stem sections become glassy and water-soaked; a delicate black mass of fungal threads and small black spherical structures may develop over the lesions. Sanitation.
POINSETTIA Bacterial (Erwinia) Stem Rot Black, water-soaked spots or lesions on stems. Lesions may girdle stems. Sanitation; pot-level irrigation; See APMH.
RED CEDAR Phomopsis Tip Blight Tips of twigs become yellowed and browned. Dieback may spread down the twig-branch. Lower foliage is affected first. Sanitation. See the APMH.
ROSE Phytophthora Root Rot Dieback; active infections are wet-rotted; old infections are dried. Sanitation; reduce watering.
SCHIP LAUREL Bacterial Leaf Spot (Xanthomonas) Angular brown spots with water-soaked margins; shot-holes develop. Sanitation.
SNAPDRAGON Cercospora Leaf Spot Pale brown angular leaf spots of variable size. Cleary's 3336, Domain, or a benomyl labelled for ornamentals
THRIFT Rhizoctonia Blight Stem and leaf browning. Sanitation; Cleary's 3336.
VERBENA Anthracnose (Colletotrichum) Circular black spots on foliage. Sanitation; Cleary's 3336.
VERBENA Pythium Lower Stem Rot Brown water-soaked lesions. Sanitation; reduce irrigation.
VINCA (Periwinkle) Anthracnose (Colletotrichum) Brown irregular areas, blotches develop on leaves and stems. Sanitation. Protective sprays of Cleary's or Domain or a WP benomyl labelled on ornamentals may help.
VINCA (Periwinkle) Phytophthora Stem Rot and/or Crown/Root Rot Stems and/or lower stems near soil line and roots become browned and water-soaked. Sanitation; improve soil drainage.
VINCA (Periwinkle) Pythium Root Rot Roots become brown decayed and water-soaked. Sanitation. Reduce watering schedule. Rotate to different crop.
VINCA (Periwinkle) Rhizoctonia Aerial Blight Lower leaves become blighted; a thin mycelial webbing may develop. Sanitation; Cleary's, Domain or a WP benomyl labelled on ornamentals may help.
WAX MYRTLE Anthracnose (Colletotrichum) Brown, irregular spots, blotches develop on leaves. Sanitation; if disease is severe, protective sprays of Cleary's 3336 or Domain or a WP benomyl may help.
WAX MYRTLE Gummy Stem Blight (Mycosphaerella) Black lesions/spots at leaf edges; elongate cracking on stem with amber-colored ooze. See APMH.

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