Can Black Knot jump from Plum to Apple?

Discussion in 'HortForum' started by jimF, May 25, 2010.

  1. jimF

    jimF Member

    Messages:
    2
    Likes Received:
    0
    Location:
    Courtenay, B.C., Canada
    Our Damson plums have all gotten Black Knot. Now the same kind of 'cancer' has shown up on some of the apple trees. Is this a new and improved Black Knot?
     
  2. Maggie76

    Maggie76 Member

    Messages:
    15
    Likes Received:
    0
    Location:
    Canoe Cove, PE, CA
    Hi Jim, I've recently been looking into the same issue, although I was more focussed on whether black knot can spread to other types of non-fruiting trees. My understanding was that black knot affects only Prunus species, however, I recently went to purchase white ash (Fraxinus) trees from a nursery only to be told that their stock had been taken over with black knot. We have a severe case of black knot on the far side of our 3 acre property on what appear to be cherry/plum trees. The disease has progressed to the point that 90% of the cherry/plum trees are dead. On the opposite side of the property we have an apple orchard (approximately a dozen apple trees). The apple trees have zero signs of being infested. Hard to say whether the apples simply aren't susceptible or the distance between the two is keeping the disease from reaching them.
     

Share This Page