Gary W. Moorman, Professor of Plant Pathology
|ASTER YELLOWS||Plants are stunted with excessive branching and yellow, strap-shaped leaves.||Phytoplasma||Destroy infected plants. Maintain good insect and weed control in the greenhouse.|
|BOTRYTIS BLIGHT||Leaves, especially those near the soil surface, rot and become covered with gray fungal growth as do fading flowers.||Botrytis cinerea||Heat and ventilate to maintain low humidity. Remove dead and dying tissue from the greenhouse. Apply chlorothalonil, iprodione, or azoxystrobin.|
|DAMPING-OFF||Seedlings wilt and die.||Pythium spp.||Plant in pasteurized potting mix. Discard infected plants. Apply mefenoxam to protect healthy plants.|
|PHYTOPHTHORA ROOT ROT||Roots rot and plants wilt and die.||Phytophthora primulae||Plant in pasteurized potting mix. Discard infected plants. Apply potassium salts of phosphorus acid, mefenoxam to protect healthy plants.|
|RHIZOCTONIA CROWN ROT AND BUD BLIGHT||Roots and stems brown. Plants wilt and die. Older plants may fail to flower or produce new leaves.||Rhizoctonia solani||Plant in pasteurized potting mix. Discard infected plants. Apply iprodione or PCNB to protect healthy plants.|
|THIELAVIOPSIS ROOT ROT||Small black spots form on roots. Gradually, the entire root system browns. Old leaves die while younger leaves yellow.||Thielaviopsis basicola||Plant in pasteurized potting mix. Discard infected plants. Apply thiophanate methyl as a soil drench to protect healthy plants.|
|VIRUSES||Leaves may be mottled, yellowed, or have dead spots or be curled. Plants are stunted. Flower color may break. Entire plants may die.||Tobacco necrosis, primrose mosaic, cucumber mosaic, impatiens necrotic spot, tomato bushy stunt, alfalfa mosaic, or tobacco ringspot.||Discard infected plants. Maintain good insect control, especially aphids and thrips.|
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)|
|hydrocarbon||PCNB||12||Revere (400-407-10404), Blocker (5481-211), Terraclor (400-399), Defend (5481-444-1001)|
|M||1||Chloronitrile||chlorothalonil||48||Daconil (50534-9), Exotherm Termil (70-223)|
|12||Echo (60063-7), PathGuard (60063-7-499), Concorde (72167-24-1812), Pegasus (72167-24-1812)|
|U||1||Phosphite||phosphorus acid salts||4||Alude (71962-1-1001)|
|potassium phosphate||4||Vital (42519-24)|
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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