Gary W. Moorman, Plant Pathology Professor
|Alternaria leaf spot||Small dark brown to black leaf spots become oblong and develop lighter-colored centers as they enlarge. Spots on young plants are often along the midrib.||Alternaria||Water in a manner that keeps moisture off the leaves and stems. Apply iprodione + thiophanate methyl or copper to protect healthy plants.|
|Aster yellows||Flowers remain green. Leaf-like structures form in place of some flower parts and tight clusters of such flowers may form. In the spring, foliage may be bright yellow.||Aster yellows phytoplasma spread by leafhoppers||Remove infected plants. Remove weeds in the area and other aster-related plants that have similar symptoms.|
|Bacterial leaf spot||Dark brown to black spots form on leaves and are angular in shape because they are limited by large leaf veins. The spots often have a yellow halo||Pseudomonas cichorii||Water in a manner that keeps moisture off the leaves and stems. Apply copper to protect healthy plants|
|Botrytis leaf spot and stem rot||Brown spotting on leaves is sometimes accompanied by a stem rot.||Botrytis cinerea||Water in a manner that keeps moisture off the leaves and stems. Apply iprodione + thiophanate methyl or copper to protect healthy plants.|
|Cercospora leaf spot||Brown spots from on the leaves. Tiny black dots are seen within the spots.||Cercospora tabacina||Water in a manner that keeps moisture off the leaves and stems. Apply iprodione + thiophanate methyl or copper to protect healthy plants|
|Foliar nematode||Purplish, angular spots form between veins. The spots become tan with age.||Aphelenchoides||Most other perennials are also susceptible to foliar nematode. Examine all surrounding plants for similar symptoms. Remove infected plants. Water in a manner that keeps moisture off the leaves and stems.|
|Leaf mottle||Light and dark green blotches develop on leaves. Sometimes there dark green ring spots present or line patterns and etches formed by dead tissue.||Impatiens necrotic spot virus (INSV), cucumber mosaic virus (CMV), and others||Remove infected plants. Control thrips (that move INSV) and aphids (that move CMV).|
|Sclerotinia and Sclerotium crown rot||Plants with dark spots on lower stems and dark roots wilt and die. White fungus with dark granule-like (Sclerotinia) or tan balls (Sclerotium) structures form on the surface of the dead areas.||Sclerotinia sclerotiorum and Sclerotium rolfsii||Remove infected plants.|
|Septoria leaf spot||Purplish-brown spots develop on the leaves, often completely covering older leaves.||Septoria lepachydis||Water in a manner that keeps moisture off the leaves and stems.|
|White smut||Yellow spots form on the leaves and become brown with age.||Entyloma compositarum||Several plants in the aster family are susceptible and should be examined for symptoms. Apply iprodione + thiophanate methyl to protect healthy plants.|
|FRAC Group No.||Risk Level||Class||Active ingredient||REI Restricted Entry Interval||Trade names (EPA Reg. no.)|
|M||1||Copper complex||copper sulfate||24||Phyton 27 (49538-3)|
|copper ammonium||Liqui-Cop (54705-7)|
|copper salts||Camelot (67690-36)|
|Copper , fixed||copper hydroxide||24||CuPRO 2005 (67690-37)|
|12 + 1||3||iprodione +||12||26/36 Fungicide (432-1414-1001)|
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Warning! Pesticides are poisonous. Read and follow all directions and safety precautions on labels. Handle carefully and store in original labeled containers out of the reach of children, pets, and livestock. Dispose of empty containers right away, in a safe manner and place. Do not contaminate forage, streams or ponds.
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