Gary W. Moorman, Professor of Plant Pathology
|Crown gall||Rough galls form on stems at the soil line or on roots. If the galls engulf the stem or root, that tissue will be killed.||Agrobacterium tumefaciens||Remove severely affected trees. Do not replace them with herbaceous or woody plants susceptible to crown gall.|
|Black canker||Black areas form on leaves and spread to engulf and kill larger woody twigs in the summer. If the weather is wet, pink spore masses form on blackened twig cankers. This disease often occurs on trees with blight. See below.||Phyalospora miyabeana||Do not plant highly susceptible cultivars in the landscape.|
|Blight or scab||Newly formed leaves and twigs are quickly browned in the spring during wet weather. Infected leaves fall. Olive-brown spores form on the surface of infected tissue.||Venturia saliciperda||Apply mancozeb, copper hydroxide, myclobutanil, or azoxystrobin to protect the foliage of highly valued trees.|
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)|
|M||1||Copper, fixed||copper hydroxide||48||Kocide (352-656), Champion (55146-1)|
|Dithiocarbamate||mancozeb||24||Dithane (707-180), FORE (707-87), Pentathlon (1818-251)|
|manganese + zinc||24||Protect T/O (1001-65)|
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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