Rhododendrons: Messenger on Rhodos

Discussion in 'Ericaceae (rhododendrons, arbutus, etc.)' started by GRSJr, May 11, 2006.

  1. GRSJr

    GRSJr Active Member 10 Years

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    Some time ago I posted about the use of Messenger on Rhododendron.
    I reported some remarkable successes against phytopthora root rot, but also some failures. Here's another failure and a partial success.

    Rhododendron x 'Dexter's Champagne' W. C. Slocock 1946
    There were two plants planted very close together. Both have received drenches of Subdue twice every year.

    The first to contract the disease was treated with Messenger twice. Most of the plant died, but one large branch recovered and is doing well.

    The second plant didn't show symptoms until this winter (it had been treated with Messenger at the same time as the first plant and again last spring). By the time I got out there and noticed, it was pretty bad. I treated it 4 tmes with Messenger to no avail. I removed it yesterday.

    So, Messenger isn't fool proof. Perhaps if I'd treated it sooner????
     
  2. Ron B

    Ron B Paragon of Plants 10 Years

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    2 plants is not enough of a sampling to reach useful conclusions.
     
  3. GRSJr

    GRSJr Active Member 10 Years

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    I think my conclusion is valid. It would only take 1 plant to reach it.

    Actually many more than 2 were tested.
     
  4. Ron B

    Ron B Paragon of Plants 10 Years

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    I still see nothing that I would take over all of the counterindications reported here:

    http://www.puyallup.wsu.edu/~Linda Chalker-Scott/Horticultural Myths_files/Myths/Harpin.pdf

    For starters, what method was used to determine that the plants were infested with water molds in the first place?

    What number of test subjects was used? What number of controls? How was it determined that these were all of equal status before the product was applied (to half of the block?)

    How was it determined afterward that the water molds had abated? What method has been used to monitor and quantify the results?
     
  5. GRSJr

    GRSJr Active Member 10 Years

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    Quote:
    Messenger isn't fool proof.
    I think my conclusion is valid. It would only take 1 plant to reach it.

    I believe this is in agreement with the report you reference.

    On the other hand, there was a remarkable and lasting improvement in some Rhododendron here after being treated with Messenger. Probably an act of God and not atributable to Messenger at all. Still, a wonderful result that didn't happen to the untreated plants.

    A scientific study? Certainly not. Was never intended to be one.

    You have your opinion, I have mine. I'd like to see the "scientific study" that proves Messenger never works before I accept your conclusion.

    So please stop bugging me about it.
     

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