Agriculture: Cherry Pest Management Guidelines

Eutypa Dieback

  • Eutypa lata
  • Symptoms and Signs

    Eutypa dieback, also known as Cytosporina, gummosis, and limb dieback, causes limbs or twigs to wilt and die suddenly in late spring or summer with the leaves still attached. The bark has a dark discoloration with amber-colored gumming; infected areas in the interior of the wood are discolored brown.

    Comments on the Disease

    This fungus infects fresh pruning wounds when rainfall occurs within 6 weeks after pruning. While infections can occur at any time of the year during rainy periods, the greatest incidence is in fall and winter.

    Management

    Remove infected limbs at least 1 foot below any sign of the disease. The preferred control method is to prune during July and August after harvest. There is less regrowth from pruning cuts if pruning is done in August. Ideally, pruning should be completed at least 6 weeks before the first fall rains. Wound treatments with paints or sealants have not been satisfactory because of lack of efficacy or difficulty in treating all of the pruning wounds immediately after being made. If pruning wounds are made outside of the preferred pruning period of July to August, use a fungicide to treat the wounds.

    Common name Amount per acre REI‡ PHI‡
    (Example trade name) (hours) (days)
    Not all registered pesticides are listed. The following are ranked with the pesticides having the greatest IPM value listed first—the most effective and least likely to cause resistance are at the top of the table. When choosing a pesticide, consider information relating to the pesticide's properties and application timing, honey bees, and environmental impact. Always read the label of the product being used.
     
    A. THIOPHANATE-METHYL
      (Topsin M WSB) 1 lb/5 gal water 48 (2 days) 1
      MODE-OF-ACTION GROUP NAME (NUMBER): Methyl benzimidazole (1)
      COMMENTS: Requires a Special Local Needs (Section 24C) registration.
    Restricted entry interval (REI) is the number of hours (unless otherwise noted) from treatment until the treated area can be safely entered without protective clothing. Preharvest interval (PHI) is the number of days from treatment to harvest. In some cases the REI exceeds the PHI. The longer of two intervals is the minimum time that must elapse before harvest.
    1 Group numbers are assigned by the Fungicide Resistance Action Committee (FRAC) according to different modes of actions. Fungicides with a different group number are suitable to alternate in a resistance management program. In California, make no more than one application of fungicides with mode-of-action group numbers 1, 4, 9, 11, or 17 before rotating to a fungicide with a different mode-of-action group number; for fungicides with other Group numbers, make no more than two consecutive applications before rotating to fungicide with a different mode-of-action group number.
    Text Updated: 09/15
    Treatment Table Updated: 09/15
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