Gary W. Moorman, Professor of Plant Pathology
|Botryosphaeria canker||Leaves on affected branches wilt and die. Branches die back and become covered with dark-brown to black pimple-like fungal fruiting structures. Wood under the bark is dark brown.||Botryosphaeria||Plants most susceptible are those under drought stress. Therefore, irrigate to prevent drought stress. Prune infected branches.|
|Downy mildew||Angular spots limited in shape by the leaf veins form blotches that die and shrivel in the spring when the weather is wet. Severely affected leaves fall. Light- colored fungal growth sparsely covers the spots on the underside of the leaf.||Plasmopara viburni||Rake and destroy fallen leaves in the autumn. Avoid overhead irrigation in the spring. Apply azoxystrobin or chlorothalonil + thiophanate methyl.|
|Powdery mildew||White fungal growth forms on the upper surface of leaves.||Erysiphe or Phyllactinia||No control is recommended since little damage occurs. If severe, apply azoxystrobin, triadimefon, chlorothalonil or myclobutanil.|
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.)|
|1||3||Benzimidazole||thiophanate methyl||12||3336 (1001-69), OHP 6672 (51036-329-59807), Fungo Flo (51036-329-59807), Systec 1998 (48234-12)|
|3||2||Triazole||triadimefon||12||Strike (3125-436), Bayleton (432-1360)|
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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