Black Pine Problem

Discussion in 'Gymnosperms (incl. Conifers)' started by meppy, Oct 20, 2005.

  1. meppy

    meppy Member

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    Hi
    I have a small number of Black Pines that are in distress, see attached.
    Looks like some kind of a bug or scale etc.

    Any ideas on what the problem is and what I should do .

    Meppy
     

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  2. Michael F

    Michael F Paragon of Plants Forums Moderator 10 Years

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    It's a fungal disease, common on Pinus nigra in humid areas. Not a lot can be done about it, but it rarey kills the trees. The best action is to rake up all the leaves as they fall and burning them, that should reduce the number of spores available for re-infection of the following years needles.
     
  3. pierrot

    pierrot Active Member 10 Years

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    From the picture you have posted it seems that thepine is suffering from a needle cast disease. Dothistroma needle blight is a common needle disease that can affect over thirty species of pine trees. The first noticable symptoms are dark green, water-soaked spots on the needles. These spots become tan, yellow, or reddish-brown, and may encircle the needles to form bands. The tip of the needle beyond the band eventually dies leaving the base of the needle alive and green.

    Dothistroma needle blight is caused by the fungus Dothistroma pini (Mycoshaerella pini) and survives in diseased needles. Small pycnidia (black reproductive structures) erupt from the surface of infected needles. Spores are produced in these structures throughout the growing season, and infection can occur at any time, but particularly during periods of wet weather. Symptoms appear from five weeks to six months after infection.

    Copper-containing fungicides (e.g., Bordeaux mix) can help prevent new infections, but will not cure diseased needles. Typically a single fungicide application in early June is sufficient to provide protection of new foliage. However, a second application three to four weeks later will provide more complete control. Be sure to read and follow all label instructions of the fungicide that you select to insure that you use the fungicide in the safest and most effective manner possible. Several years of treatments may be needed to completely rid a tree of all infected needles (through natural needle loss). Trees with severe infections (> 40% of the crown affected) may not survive and should be removed.


    here is a picture from www.forestryimages.org (Robert L. James, photographer)

    I hope this helps
     

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    Last edited by a moderator: Oct 25, 2005

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