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 chlorothalonil, iprodione, or vinclozolin to protect healthy tissue.|
|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. Apply iprodione to leaves and stems. Maintain moderate temps. and low humidity.|
|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 potassium salts of phosphorus acid, etridiazole, etridiazole + thiophanate methyl, or mefenoxam to protect healthy 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 potassium salts of phosphorus acid, etridiazole, etridiazole + thiophanate methyl, or mefenoxam.|
|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
Active Ingredients and Trade Names of the Chemicals
|FRAC Group No.||Risk Level||Class||Active ingredient||REI Restricted Entry Interval||Trade names (EPA Reg. no.)|
|2||3||Dicarboximide||iprodione||12||Chipco 26GT (100-1138), Chipco 26019 (264-481), Iprodione (51036-361), Sextant (51036-361-59807)|
|4||3||Acylanine||mefenoxam||0||Subdue MAXX (100-796)|
|14||1||Thiadiazole||etridiazole||12||Truban (58185-7), Terrazole (400-416)|
|M||1||Chloronitrile||chlorothalonil||48||Daconil (50534-9), Exotherm Termil (70-223)|
|U||1||Phosphite||phosphorus acid salts||4||Alude (71962-1-1001)|
|potassium phosphate||4||Vital (42519-24)|
|1 + M||thiophanate methyl + etridiazole||Banrot (58185-10)|
Fungicides and Fungicide Resistance Management - Certain fungicides, usually systemic fungicides, are said to be 'at risk' to the development of resistance if they are used repeatedly. See the Risk Level in the above table (1 = low risk; 3 = high risk). The Fungicide Resistance Action Committee has developed a numbering system in which chemicals with the same FRAC Group number have the same mode of action (See http://www.frac.info/frac/index.htm ). It is recommended that chemicals at high risk be used sparingly and in rotation or mixed with chemicals with different modes of actions (different FRAC number).
Notice: The user of this information assumes all risks for personal injury or property damage.
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.
Issued in furtherance of Cooperative Extension work, Acts of Congress, May 8 and June 30, 1914, in cooperation with the U. S. Department of Penn State College of Agricultural Sciences research and extension programs are funded in part by Pennsylvania counties, the Commonwealth of Pennsylvania, and the U.S. Department of Agriculture.
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