• Trunk diseases?

  • Piet

    25 Luglio 2021 at 17:48

    I have a question about some trunk disease I first noticed this year in my Johanniter, a German hybrid piwi.

    This winter I transformed quit a lot of these plants to the S&S method, cutting spurs on the trunk below the head with 2 buds. On some plants a saw some canes die in July, all of a sudden. It looks like some trunk disease to me, maybe Esca if you look at the symptoms. Although there were no “tiger stripes” leaves, only a very quick browning from the leaves first and soon after the shoots start to die.

    We had quite a lot of rain in June en the beginning of July, maybe this was a trigger?

    Can someone with more experience with trunk disease comment on this? In the pdf there are several pictures with some comment.

    Thanks in advance


  • Simone

    12 Agosto 2021 at 07:31

    Hello Piet.

    Interesting pictures. As I can see from that you were pruning using crown head. So maybe it is possible you lost some live wood.

    That could be the reason to have some access points of trunk diseases.

    Anyway the sympthoms are not so clear.

    How was the climate after the rain? Dry and hot?

    For the black spot in the base of the shoot (pic2) I think it would be possible Phomopsis viticola symptoms.

    Do you have some recent pics in other plants?

    • Piet

      13 Agosto 2021 at 11:20

      HI Simone,

      Thanks for your reply. Indead, you have to download the pdf to see all the pictures.
      I also asked a German expert in Esca to comment on this. He said that this year they observerd also leaves an canes to die very suddenly. There is a acute an chronic form of esca. The actute form shows no symptoms in the wood and it can be triggered with a lot of rain followed by heavy sunlight and increased tranpiration so the toxins get transported easily in the leaves. The talk about apoplectic symtoms, a stroke. They observed this also on very young plants, even in the nursery.
      I noticed this on a few plants, all the others are normal, except the peronospora this year.
      You’r right, I’ve started branching, so the in the future it becomes better I hope. I will try to rebuild the affected plants far below the crown.

      • Simone

        17 Agosto 2021 at 12:19

        Hi Piet,

        in fact the strokes are tyical for a quick stress (temperature\water stress). After a raining season high temperature and low rain can increase the risk for strokes.

        I saw other pictures and the spongy tissue you have inside the old crown head is Esca’s clear symptom.

        Advice: According with your pictures, if you want to start the branching, try to select some shoots in spring under the crown head and cut the spur there. It is much better if you start the branching in that point, so you can take the direct sap flow before this point (full of died wood).

  • Simone

    12 Agosto 2021 at 08:59

    Excuse me i couldn’t see all the file you sent. In picture number 5 you found white spongy tissue in the wood. So for sure it is a clear symptom of trunk disease.

    You should for sure mark the plants with symptoms. You could try to open more the plant trunk and check if this tissue is only in the crown heads or it is extended in the trunk.

    If it is only located in the crown head you can try to renew the trunk from it base (over the greff point).

    Or you can try to remove all the died tissue with a chainsaw.

    Or simply estirpate….

  • Luca

    18 Agosto 2021 at 10:10

    Hi Piet,

    I agree with Simone regarding the advice and points he has mentioned.

    One thing also to keep in mind is the following. Try to reconstruct/recreate the plants away from the Crown Head. This entails locating the Crown Head where all your previous pruning wounds are. Here there will also be a large amount of desiccation and dieback internally which negatively affects the plant.

    I hope this gives you a little more insight?

    • Piet

      18 Agosto 2021 at 10:55

      Thanks Luca,
      The reconstruction of the plant is clear to me I already did this on al lot of other plants. For this one, I have to wait for the next spring for new watershoots on the trunk. There are a few spurs but they are to close to the crown head.
      I just wanted to know more about the esca symptoms and the rappid breakout this year. Thanks for your help.

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