Gary W. Moorman, Professor of Plant Pathology
|BORON DEFICIENCY||Small, dark brown to black irregularly shaped spots form at the leaf base of seedlings. Plants wilt and die as the browning spreads up the leaf blade. On older plants, flower stalks are short and wilted. Plants die.||Lack of boron||Apply boron.|
|BOTRYTIS BLIGHT||Small water-soaked lesions form on damaged petioles and spread to leaf blades. Infected flowers fade prematurely.||Botrytis cinerea||Space plants and provide ventilation to avoid high humidity. Remove fading flowers and yellowing leaves. Apply a fungicide to protect plants.|
|FOLIAR NEMATODE||Small tan, sunken areas form on leaf tips and margins. Spots become dry and dull black.||Aphelenchoides ritzema-bosi||Destroy infected plants. Water plants in a manner that keeps leaf surfaces dry and does not splash from plant to plant.|
|MYROTHECIUM ROT||Petioles of lower leaves develop darkened spots. Spots enlarge down stems and stems are easily broken.||Myrothecium roridum||Plant in pasteurized media. Maintain moderate temps. and low humidity. Apply a fungicide to protect plants.|
|PHYTOPHTHORA CROWN ROT||Crowns and roots have a dark, water-soaked appearance. This spreads to petioles and leaf blades. Young plants are quickly killed. Rhizomes of mature plants resprout but eventually succumb.||Phytophthora nicotianae, P. cryptogea||Do not propagate from infected plants. Pot in pasteurized media. Destroy infected plants. Apply a fungicide to protect plants.|
|PYTHIUM ROOT ROT||Roots are dark brown. Plants wilt, yellow and die.||Pythium||Do not overwater plants. Pot in pasteurized media. Keep hose ends off the ground. Apply a fungicide to protect plants.|
|VIRUSES||Leaves may be downwardly cupped, mottled, or strap shaped. Leaves may have line or ringspot patterns. Shoots may be elongated.||Tobacco mosaic, tomato ringspot, and impatiens necrotic spot virus||Maintain good thrips control. Do not take cuttings from infected plants. Destroy infected plants. Eliminate weeds within the production area. Use very fine mesh screen to keep thrips out. Do not use tobacco products when handling plants.|
Impatiens necrotic spot virus symptoms
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