Our Little Grapefruit Tree Needs Help

Discussion in 'Citrus' started by LBobirca, Aug 27, 2005.

  1. LBobirca

    LBobirca Member

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    Our little tree is not doing well. I did a search and found a wounderful post by Mr. Shep who helped Sue from Nova Scotia save her tree. We live in Southern California and he was going well until we moved a few months ago. He has been getting little bumps on the leaves and a few days ago the leaves started to droop. In addition there are a lot of ants that are crawling all over the plant and in the soil. My wife and I have taken good care of him since he was just a seed in my breakfast. He is three and a half years old and we have had him since my wife and I started dating. We are very attached to him and feel like he is our child. That being said it has been hot here and I am wondering if he has gotten too much sun and or heat. If you are out there Mr. Shep please help.
     

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  2. Junglekeeper

    Junglekeeper Esteemed Contributor 10 Years

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    Hi, LBobirca. Your poor grapefruit tree is infested with scale (the bumps). The ants are attracted by the 'honeydew' that they exude. Get rid of the scale and the ants will disappear as well. Here's what I would do:
    Get some insecticidal soap, an old toothbrush with soft bristles, a small container that's big enough for you to dip the toothbrush into, and a small plastic shopping bag.

    Slice the bag at one end and wrap it around the main stem so as to cover the soil surface then fasten with a twist tie. (This minimizes splatter and prevents most of the scale from falling into the soil.) Fill the container with i-soap, wet your toothbrush with it and methodically scrub (gently) all plant surfaces removing all the adult scale. Hose off the plant with water and finish up by spraying all plant surfaces with the i-soap. Wait five days then spray the entire plant with the i-soap again. Repeat the spray once or twice more.

    The telltale sign of scale, even when you don't see them, is the presence of spots of sap on the leave surface. It's best to treat before you see the adult scale.

    Good luck.
     
  3. LBobirca

    LBobirca Member

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    Thanks Junglekeeper, I removed all of the scales and transplanted our little guy to a new pot with new soil. My main concern is his droopy leaves. It has been hot here and I'm not sure if it from the heat or from the scales that he looks so bad. Could the scales be causing him to have droopy and curly leaves?

    Thanks again for all your help.
     
  4. mr.shep

    mr.shep Well-Known Member 10 Years

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    The scale alone will not cause the leaves to
    droop. The leaves can show some yellow
    mottling in the veins of the leaves and parts
    of the leaf due to scale. Generally, only
    heavy outbreaks of scale will cause the
    leaves to curl due to the insect.

    Here where I am, insecticidal soaps are for
    the most part considered a waste of time and
    effort but if we remove as many of the scale
    caps as we can before a spray or immersed
    in a dip solution then we can have some
    effectiveness using an insecticidal soap.
    I really like the suggestion of using an
    old toothbrush to clear away the scale
    caps. We have to expose what is under
    the caps in order for us to effectively
    attack this insect without the usage of
    biological control.

    Sometime look at this link below. Should
    the insecticidal soap not be effective, then
    other controls are listed in this link. I would
    still want to clear off as many of the caps
    before use of any chemical spray. I have
    removed them by hand in the past and then
    used Sevin. The current better control for
    usage here in the San Joaquin Valley is bio
    control, a predator insect used to combat
    this scale insect.

    http://www.ipm.ucdavis.edu/PMG/r107301111.html

    I am battling this same scale also this year
    and have used showers of water to keep the
    scale at bay and localized to a small Southern
    part of the infected Lemon tree. Also, ants
    can protect scale by helping ward off the
    natural enemies to the scale. You may want
    to learn where the ants are coming from and
    attack their nests either with a spray or use
    of an ant bait. If you know exactly where the
    ant nests are sprinkle some table sugar on
    the ant mound. Ingested sugar by the ants
    will "tear up their insides" is how it was put
    to me several years ago. I've used honey
    baited jar traps for years for ant suppression.

    Container grown Citrus have a tendency to
    dislike having their root growth restricted
    for long periods of time. An indication
    of the roots not being happy will be seen
    in the curling of leaves. Other factors such
    as the Whitefly can cause the leaves to curl
    also.

    I would want to know how often you watered
    this tree before the transplant. How often
    have you fertilized this tree and what was
    the fertilizer that was used? You cannot
    allow standing water for any length of time
    for a container grown Citrus. If the water
    that was used is collected in a pan or tray
    then empty the water soon after the water
    has drained through the pot. No need to
    concern yourself if the water is allowed to
    drain out of the pot naturally without being
    collected.

    I have a suggestion in that you clear some
    of the potting soil out the pot for now to
    allow for more water to be applied when
    you want to water. I'd take out about 1-2
    inches of soil if you can unless you do not
    mind several small applications of water
    rather than one or two medium applications
    for each watering.

    Citrus can handle warm to hot weather. They
    will not balk much unless we are not watering
    them enough. Citrus do best when grown in
    full sun but can take afternoon shade or even
    morning shade in hot locations and then rest
    of the day sunlight. By the coloring of the
    leaves of your tree I would not worry about
    the location where you have this tree. Too
    sunny a location or too hot a climate is not
    an issue by the looks of your tree for leaf
    color. The droopy leaves does raise an issue
    but this can be the result of transplanting the
    tree and not giving it enough water when the
    transplant had been achieved but could also
    mean that the roots were not happy before the
    transplant took place. We will see the leaves
    droop when the Citrus grown in a container
    have not been watered enough. A constant
    droop in the leaves could mean a root rot
    fungus has attacked due in part to the soil
    medium used along with too much wetness,
    due to too much water being applied too
    often and from too little water and not
    enough sunlight. Too little water can also
    cause the leaves to curl.

    Jim
     
  5. Junglekeeper

    Junglekeeper Esteemed Contributor 10 Years

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    Jim,
    If in fact the plant is suffering from root rot, would it be beneficial to use bottom heat to increase the soil temperature to 29-36C, the optimal range for citrus root growth? (I got the range from one of the more technical books on citrus.)
     
  6. mr.shep

    mr.shep Well-Known Member 10 Years

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    Location:
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    Sometime tell me of your indoor set up for
    Citrus.

    If your question is a dual one in which on one
    side of the equation you want to keep the roots
    warm to allow them to continue to grow, as they
    will if given the right conditions and on the other
    side to allow heat to inhibit a water mold form
    of a fungus, most likely emanating from the soil,
    from attacking the Citrus then I think you have
    the right idea. If you can keep the roots warm
    during the Winter you have a much better chance
    of having fruit ripen for you. I hope you know
    you are in the process of solving someone's
    Avocado dilemma for them. Now, the question
    I have is how do you plan to do it in an indoor
    environment? I am just curious but I do like
    where your thinking is heading.

    We seldom see a water mold form of
    Phytophthora here in the San Joaquin
    Valley as our soil temperatures tend
    to be too warm for them to flourish in.
    Only in container grown plants may
    we sometimes see them but from
    plants that generally did not originate
    from here.

    Below is a IPM link in reference to the
    gummosis form of Phytophthora on
    Citrus.

    http://axp.ipm.ucdavis.edu/PMG/r107100411.html

    Best regards,

    Jim
     
    Last edited: Aug 29, 2005
  7. Junglekeeper

    Junglekeeper Esteemed Contributor 10 Years

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    My apologies, LBobirca. Didn't mean to hijack your thread; I posed the question as my lemon tree shows symptoms of root rot. Feel free to steer the thread in the direction as you see fit.

    Since feeder roots have been destroyed, I wondered if the heat would encourage new root growth without ill effects. Phytophthora parasitica has an optimal growing temperature near 90F/32C - which happens to fall in the range for ideal citrus root growth. [Ref: Two Phytophthora's To Worry About] So which would benefit more from the heat, the roots or the fungus? In addition, would it be better or worse to allow the plant, in its present condition, to enter dormancy in winter?

    I would place a heat mat (made for seeds) underneath the pot. It'll raise the temperature - monitored using a soil thermometer - to several degrees above ambient room temperature. The distance between the mat and the pot will be adjusted as required to achieve the desired heat level.

    Nothing fancy. Just an enclosed balcony, south-facing and unheated. Temperatures in winter will likely allow citrus to go dormant for a short period. However this is not a sure thing because of the fluctuation in daytime and nighttime temperatures.
     
  8. mr.shep

    mr.shep Well-Known Member 10 Years

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    So which would benefit more from the heat, the roots
    or the fungus?


    The plant would benefit more than the fungus from
    the added heat. We can treat the tree for the fungus.

    A lot depends on which form of Phytophthora you
    have. Since you referenced in another thread your
    Lemon showing gummosis symptoms, I think seeing
    some photos of these symptoms may help determine
    which form you have. If you can tell me the sourcing
    of this tree such as did it come from California and
    which nursery it came into Canada from, may also
    help.

    In addition, would it be better or worse to allow the
    plant, in its present condition, to enter dormancy in
    winter?


    Let’s see what the symptoms on the plant are. Citrus
    do not go entirely dormant anyway, even with cooler
    day and nighttime temperatures along with less hours
    of sunlight or grown indoors, less intensity of light.

    The more destructive Phytophthora are the ones that
    prefer cool and moist conditions. I’ll have to check
    this out sometime (can’t do it too well here) but I
    remember a form that seems to affect the fruit with
    brown rot type symptoms with some gummosis
    showing on the exterior of the fruit. The gummosis
    from that form is not necessarily visible on the trunk
    and branches of the tree.

    Jim
     
  9. Junglekeeper

    Junglekeeper Esteemed Contributor 10 Years

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    The Meyer lemon that had gummosis has been disposed of. It didn't look like it was going to survive and I didn't want to risk having it infect the other trees. The Lisbon lemon is the one with the root rot. It's not looking too bad even though its leaves have a slight wilt. It'll probably pull through on its own in time but I'd like to help it if I can. Both are Monrovia trees from Visalia, California.
     
  10. Junglekeeper

    Junglekeeper Esteemed Contributor 10 Years

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    It looks like it's finally safe to declare the experiment with the heat mat a success. When the Lisbon lemon was placed onto the mat it had dull, wilting foliage and was in a slow decline. The leaves perked up and took on a deeper green after two weeks into the treatment. The process of dormant buds waking up and breaking out was and still is extremely slow. The duration of treatment was 19 weeks from the start to seeing the beginnings of leafy growth. This would likely have been reduced with better lighting.
     

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