Discussion in 'Fruit and Nut Trees' started by Unregistered, May 26, 2004.

  1. Last summer our peach tree made the most beautiful looking fruit yet when you broke into the peaches they were rotten inside. What would cause this & what, if anything, can be done about it to prevent it from happening again this year? The tree is already starting to make peaches again...
  2. mr.shep

    mr.shep Well-Known Member 10 Years

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    San Joaquin Valley, California
    There are three schools of thought that cause the deterioration
    of the flesh in Peaches as the fruit is ripening.

    1. The most prevalent thought without seeing the actual damage
    and the color of the rotting is that there is IB, internal breakdown
    of the flesh caused by a physiological disorder. There are certain
    varieties of Peaches and Nectarines that are more susceptible than
    others in yielding fruit that have ongoing flesh decay without showing
    any outward characteristics in or on the fruits skin. No lesions, no
    browning, no nothing to let you know in advance of something wrong
    internally. Also, improper storage of the ripe fruit after picking can
    cause an IB condition to come about.

    2. For a long time it was thought that Brown rot and Hull rot,
    both Monilinia laxa and Monilinia fructicola could cause the
    flesh to breakdown. I feel that most of the symptoms we have
    in the fruit of Peaches from these diseases can easily be identified
    by the rotting of the basal end of the fruit which becomes noticeably
    discolored due to the soft tissue breakdown and then subsequent
    rotting. That to me is Hull rot.

    Brown rot is a little more tricky in that in most cases we will see
    a wet spot on the fruit, generally not in the basal end but somewhere
    else such as on the body of the fruit and even the top portion of the
    fruit. The other difference is we will see a whitish mycelium build
    up much sooner than from Hull rot. It is still possible that Brown
    rot, at one time it was thought that it surely did much more so than
    Hull rot, can also cause internal damage without symptoms showing
    on the outside of the fruit (mainly Peaches as it is rarely seen on

    We can suppress both diseases by fungicide sprays when the tree
    is in early bloom to late bloom as well as cultural practices to
    remove and discard of any mummies left on the trees. It is the
    latter that is quite important but a Copper or Calcium Sulfate
    spray, for example, during bloom prior to petal fall is almost

    3. Here is where I will get into trouble but I know it is true but I am
    not sure to this day there has been much scientific work done on
    it. In some varieties of Peaches and Nectarines there is a gap
    that starts to develop where the stem meets the top portion of
    the fruit. I've often wondered where and how certain fruit beetles
    could enter a Peach and Nectarine without any outward appearance
    of an attack on the fruit. After some close inspection I saw where the
    beetles could enter as with the weight of the fruit there is an abscission
    like layer at the top where it meets the stem that causes a very small
    opening into the fruit. It is there that a bacteria or a fungus can attack
    the internal portion of the fruit without us knowing it until the fruit
    is sliced in half. In Red Delicious Apples it is called Moldy Core
    caused by Alternaria alternata. I believe the possibility that the same
    pathogen can also attack a Peach and in some rare cases Nectarines.
    Instead of an opening at the calyx such as on an Apple, an opening
    between the lower portion of the stem as it is attached to the fruit,
    which can allow the fruit to fall off the tree on its own can cause the
    entryway for the rotting problem you are experiencing.

    Either you have a physiological disorder going on with the particular
    variety of Peach you have or you have an invader coming in while the
    Peach is ripening. For the latter there is no recommended control or
    suppressant for that close to harvest. Should your Peaches continue
    having the same rotting symptoms in the next few years after using a
    fungicide regimen in the early Spring, then you may want to discard
    your tree and grow another variety of Peach instead.

    An excellent question and one that the scientific community would have
    some real problems trying to answer. There has been some real discord
    between Farm Advisors and Pomologists over this issue for years, at least
    35 years that I know of.

    Next time join the UBC forums. I generally do not respond to unregistered

  3. Thank you for making the exception & answering in this case. I'll pass all this info on to my father (he does most of gardening in the family) & will join the forums soon.
  4. mr.shep

    mr.shep Well-Known Member 10 Years

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    San Joaquin Valley, California

    Fruit Trees are one of my areas of long term interest. I am still
    learning them! You asked such a good question that I could not
    leave it alone.

    I initially learned the problem you are having as being due to Brown
    rot. Later on I was told that certain varieties of Peaches could in some
    cases experience an internal breakdown of the flesh which was and
    still is considered quite a rare event for us to see here in the San
    Joaquin Valley. The IB problem with varieties of Peaches is more
    prevalent in cooler and more humid areas than ours. I do not know
    where you are growing your Peach or your variety but you will want
    to initiate a fungicide spray program in the very early Spring as there
    are no real alternatives should you have a Brown rot problem. For an
    IB problem caused due to a variety you can help it somewhat with the
    help of timely fertilizations with a granulated fertilizer having about
    10% Calcium as a nutrient amendment such as in the Winter while the
    tree is dormant and best done in the early Spring. Any granulated
    fertilizer application during the growing season must be accompanied
    by a few deep waterings to better incorporate the fertilizer down to the
    root zone without injuring the roots.

    Please do join the forums, everyone is welcome no matter the novice
    in plants, the backyard grower all the way to the professionals.

  5. Eglantinerosie

    Eglantinerosie Member

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    Zionsville, Indiana
    How to plant dwarf peach trees?

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