|Alternaria Leaf Spot||Brown spots and rings form on infected leaves.||Alternaria||Reduce humidity and maintain good air circulation. Space plants for good air circulation. Apply a fungicide registered for use on impatiens.
|Botrytis Blight||Flowers are spotted and stems rot.||Botrytis cinerea||Reduce humidity and maintain good air circulation. Do not space plants too closely. Remove fading flowers and yellowing leaves. Apply a fungicide registered for use on impatiens.|
|Bacterial Fasciation||Plants stunted and have many short shoots at the crown.||Corynebacterium fascians||Discard infected plants. Do not propagate from infected plants. Propagate and plant in pasteurized potting media.|
|Damping-off||Stems at the soil line die and plants collapse.||Pythium or Rhizoctonia||Plant in pasteurized potting media. Keep hose ends off the ground.|
|Powdery Mildew (New Guinea impatiens)||White, mealy fungal growth develops on the top of leaves. Sometimes, heavy gray growth develops.||Oidium||Apply a fungicide registered for use on impatiens.|
|Pythium Root Rot||Lower leave wilt, leaves fall, and the plant dies.||Pythium spp.||Pot in pasteurized, pathogen-free media. Keep hose ends off the ground. Apply a fungicide registered for use on impatiens.|
|Thielaviopsis Root Rot||Roots become dark brown and rot. Lower stems have sunken lesions when infected.||Thielaviopsis basicola||Pot in pasteurized, pathogen-free media. Keep hose ends off the ground. Apply a fungicide registered for use on impatiens.|
|Verticillium Wilt||Lower leaves yellow and fall. Infected plants may recover.||Verticillium dahliae||Pot in pasteurized, pathogen-free media. Do not take cuttings infected plants.|
|Virus||Ring spots on leaves. Death of growing tips. Severe stunting.||Impatiens necrotic spot virus||Discard infected plants. Control thrips that carry the virus. Do not propagate from infected plants.|
Alternaria leaf spot.
Impatiens necrotic spot virus symptoms.
Prepared by Gary W. Moorman, Professor of Plant Pathology
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