Scale on Key Lime, Please help.

Discussion in 'Citrus' started by burly, Jun 7, 2008.

  1. burly

    burly Member

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    Hello,

    I have potted Key lime trees and a Meyer Lemon about 5 years old that have scale. They were fine until this past winter indoors when I noticed it.
    I did try the 1 % horticultural oil solution spray on a single plant in May once the plants were moved outside. The plant was sprayed at night, but after a few days, the leaves and green stems appeared lighter and somewhat mottled in colour and not healthy looking. The other citrus in the exact same location look fine, except for the scale.
    I marked a branch on a different tree just recently and sprayed only that branch and the same thing occurred within a couple of days.
    I will try and get a picture, but obviously the oil has caused this.

    Should I try a different type of oil or treatment? Maybe reduce the strength further.
    I want to avoid damaging the plants further, but would like to eliminate the scale.
    The label says Concentrated Horticultural Oil Insect Spray.
    Contents :Mineral Oil 97%


    thanks,

    Mike
     
  2. squirrelmaniac

    squirrelmaniac Active Member

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    You say you sprayed them once you moved them outside- it sounds to me like the damage that was caused (especially a mottled leaf appearance) was from spraying the plant in the sun, or right before it got very sunny. Small water droplets act like magnifying glasses on leaves, and burn them in the sun, or even under a hot light.
     
  3. photopro

    photopro Well-Known Member

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  4. drichard12

    drichard12 Active Member 10 Years

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    I use Safer Insecticidal Concentrate Soap. For all my pest problems. I may need to spray a few times. "No big deal". I get a few leaf eaters in the early summer, but they back off after eating the untreated leaves, Brown Scale is the biggest problem in the fall this works great.
     
  5. burly

    burly Member

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    I did spray the plants at night and out of the sunlight. The sun may have been out the next day, but I did not spray them in the sunlight.
    I'm not sure what to try next.

    thanks,

    Mike
     
  6. Millet

    Millet Well-Known Member 10 Years

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    Horticultural oils, that are sprayed in the late evening (or at night) it does not matter if the following day is hot and sunny. Horticultural oil correctly applied, I have personally never seen or heard of a tree suffering any type of damage. In fact many people use oils as leaf shine on house plants. What was the trade name of the product you used? Without pictures to see, I doubt that any real damage was done. - Millet
     
  7. photopro

    photopro Well-Known Member

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    Just a note. I sprayed with oils for over three years trying to kill scale and their eggs. It never worked. They always came back.
     
  8. mr.shep

    mr.shep Well-Known Member 10 Years

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    Below is an link to an overview that will
    help give more incite into scale.

    Scale Management Guidelines--UC IPM

    First order of business is identify the
    scale insect that is a problem and
    then determine a means to get rid
    of it. Our approach to attacking a
    scale indoors in the home, in a
    greenhouse or even in an enclosed
    atrium can and may differ somewhat
    as the use of certain beneficial insects
    indoors may require containment,
    which some home growers may
    not be able to achieve. With oil
    sprays indoors to be effective we
    want coverage on both the faces
    and the undersides of the leaves.

    Some of the armored scale may not
    be adequately eradicated even with
    one or a few timely horticultural oil
    sprays. A ground based approach
    may also be needed in that some
    of the armored scale can live and
    overwinter in the soil (University of
    Florida/IFAS EDIS). We can knock
    scale down one year and they can
    be right back the next, if we are not
    fully aware of which scale we are
    dealing with.

    Jim
     
  9. squirrelmaniac

    squirrelmaniac Active Member

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    Scale is always a huge battle to get rid of- if the oil didnt work, i'd try using it in a heavy concentration than recommended in the bottle. If that doesnt work, try mixing 2 table spoons of mild dish detergent with every gallon of oil mixture. This breaks the surface tension of the water, and helps drown the buggers. If THAT doesnt work...I'd say those parasites are your best bet, short of scrubbing the whole tree by hand (which i've done plenty of times)
     
  10. photopro

    photopro Well-Known Member

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    That certainly may work.

    In my case, I had scale in a controlled environment inside a private botanical garden. The garden is filled with natural rain forest animals and very rare exotic plants. Oils kill many of the desirable entities inside that atrium. Many public gardens refuse to use such treatments preferring to use natural controls. I found these natural control insects on the advice of a highly qualified botanist!

    Although everyone prefers to ignore my posts on several threads regarding these natural insects control methods. THEY WORK! They are not inexpensive but again, They work! My garden is now virtually scale free.

    The insect is a beetle known scientifically as Lindorus lopanthae. Read about it here:
    http://www.rinconvitova.com/Scale control.htm
     
    Last edited: Jun 8, 2008
  11. skeeterbug

    skeeterbug Active Member

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    I agree that natural predators are the best way to go when possible, but there are times when no predators are available or the time it would take to get them is too long.

    I have bought lady bugs and mantis, and I try to protect my assasin bugs and lacewings when I can. My main use of oil is to control leaf miners and I only spray it on new growth.
     
  12. photopro

    photopro Well-Known Member

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    I've purchased up to 5000 lady bugs with zero success on scale at any one time. Lindorus lopanthae works! Delivery has always been at least the second day by Fed Ex and/or UPS. This company is the largest and only producer of this beetle. All others buy from them.
     
  13. Millet

    Millet Well-Known Member 10 Years

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    Photopro says........'They (scale) always came back'. The fact that scale comes back has nothing what so ever to do with horticultural oils, nor would it have anything to do with ANY TYPE of eradication program or eradication chemical. An oil spray cannot control future generations of scale not yet present, that will attack at a later date. One major benefit of properly used Horticultural Oils, is that they DO NOT kill beneficial insects, therefore many public botanical gardens actually do use horticultural sprays as one part of a pest control program. Presently, horticultural oils are the number one control of scale in every citrus growing nation world wide, so they must work for someone. If you think that oil sprays do not work for you, than please use whatever you feel comfortable with. Take care, and the best to your trees. - Millet
     
  14. Millet

    Millet Well-Known Member 10 Years

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    Photopro, why would you purchase Lady Bugs, for the control of scale. Scale is not on the Lady bugs diet, therefore Lady Bugs, are not interested in scale in the least. - Millet
     
  15. Junglekeeper

    Junglekeeper Esteemed Contributor 10 Years

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    I was told horticultural oil, when used in a more concentrated form as a dormant oil, would defoliate a plant.
     
  16. Millet

    Millet Well-Known Member 10 Years

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    Junglekeeper is correct. Only use any chemical at label rates. - Millet
     
  17. photopro

    photopro Well-Known Member

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    Sorry, if this is going to become combative, I have to bow out.

    I stand by every single word I wrote. I correspond on a near daily basis with 5 botanists and the curators of two botanical gardens. These professionals check the information on my website for accuracy. Some 200,000 people annually read my site. That number is verified by a website tracking service. But if you or anyone prefers to use oil, feel free.
     
  18. mr.shep

    mr.shep Well-Known Member 10 Years

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    No one is going to disregard your posts, photopro,
    in regards to using biological agents that you have
    found to be successful for you to suppress invading
    insects. The problem we have in Citrus is that some
    scale are not easily warded off or even hampered
    much with the use of biological insects at this time.

    Granted, in normal growing conditions we may
    have a percentage kill from natural predators
    and it is our predator populations that we
    certainly do not want to kill off. Most of the
    time I use water jet sprays to liberate the
    hard to get rid of Yellow scale on my old
    Meyer Lemon into the air in 100 degree
    weather. When the scale come back I
    attack the ant nests in the ground using
    granulated sugar or better yet crystalline
    honey that pretty much wipes them out
    and pretty soon I no longer see the affects
    of the Yellow scale but they will be back
    the next year if I keep this method of non
    pesticide use going indefinitely. What I
    should spray sometime is the host
    Grapefruit tree that harbors the Yellow
    scale and the Citricola scale but since
    the tree is not mine and adjoins our two
    properties, I do not feel right about spraying
    that seedling Marsh Grapefruit that I grew
    from seed years ago when I know the
    fruit will be fresh eaten by our neighbors.

    Millet is correct about horticultural oils which
    is still the primary method of choice for the
    soft scales in many Fruit & Nut trees used
    as a stand alone dormant, pre popcorn, pre
    full bloom and pre petal fall spray. No one
    has yet mentioned an insecticide to be
    mixed in with the horticultural oil. For
    indoor plants I would advise against using
    an insecticide unless it was absolutely
    necessary. For outdoor trees then we
    have more leg room to maneuver in if we
    feel the need to use an insecticide such
    as a low grade, all things considered,
    organo-phosphate Diazinon along with
    our Spring oil spray application, which
    is still used today in many production
    Fruit & Nut tree orchards out here.

    Scale are not all created equal such
    as comparing Oyster scale which can
    be harbored on several ornamental
    plants and may not be a problem
    other than being unsightly. Red
    scale on Citrus is a whole other
    matter as a serious outbreak with
    this insect can kill trees. Effective
    biological control that will kill a wide
    array of armored scale as well as
    soft scale will always be welcomed
    and preferred by a host of people
    but one insect will not be specific
    enough yet to deal with the wide
    range of scale that can affect the
    livelihood of the Citrus trees in a
    production grove setting or even
    in a greenhouse either. I realize
    a lot depends on the voracity of
    the scale but dealing with one
    scale in a greenhouse with no
    helper insects generally is easier
    to contend with than the same
    scale might be outdoors with
    ants that can help protect the
    scale from the predator insects.

    Jim
     
  19. Junglekeeper

    Junglekeeper Esteemed Contributor 10 Years

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    Is horticultural oil appropriate for use for plants that stay indoors all the time? Wouldn't the oil remain on the foliage forever because of the lack of rain to wash it off? And wouldn't the oil then eventually capture dust and hold on to it? Does the oil pose a problem for home furnishings? (So many questions!)
     
  20. Millet

    Millet Well-Known Member 10 Years

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    Photopro, it is no ones wish to be combative. We appreciate all postings, including yours, and all points of view are appreciated. Do whatever works for you. The difficulty that I see, due to this being a citrus forum, is that we are stating what is a standard method for the control of scale in the CITRUS industry, and also in the fruit industry in general. You are stating various control methods that you have tried in the botanic garden industry. Anyway, we are all grateful for your input. Lastly, I am going to have to spend some time on your web site, as I am sure I will find it quite interesting. Take care. - Millet
     
    Last edited: Jun 9, 2008
  21. skeeterbug

    skeeterbug Active Member

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    Junglekeeper, I have not used oil indoors, but as a chemist, I do not see a problem. It will not last forever, as it will evaporate slowly. It is about the same as mineral oil which is often in lotions. It may increase the dust collecting on leaves a little, but unless it is a very dusty house, it should not be a problem. I would take the tree outside to spray it to avoid getting the overspray on other things.
     
  22. Junglekeeper

    Junglekeeper Esteemed Contributor 10 Years

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    Thanks for sharing your thoughts, skeet. I get a feeling not many people have used horticultural oil on their houseplants because of similar concerns so feedback based on experience on use in other settings is helpful. I probably should have started a new thread in the pest management forum to cast a wider net.
     
  23. squirrelmaniac

    squirrelmaniac Active Member

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    "I was told horticultural oil, when used in a more concentrated form as a dormant oil, would defoliate a plant."

    To be honest, i've never even used horticultural oil before, i've always used olive oil and dish soap mixed in water, which works great for me!
    I offered the suggestion of bumping up the dose a little, based on my experiences with olive oil. I didnt realize this product was an actual chemical, i assumed it was a natural oil.


    "Is horticultural oil appropriate for use for plants that stay indoors all the time? Wouldn't the oil remain on the foliage forever because of the lack of rain to wash it off?"
    Junglekeeper, one practice i do and recommend to anyone, is to spray your indoor plants twice a day with a garden-type sprayer, to simulate rain. the plants love the humidity, and it keeps the leaves clean! just a suggestion anyway.
     
  24. Junglekeeper

    Junglekeeper Esteemed Contributor 10 Years

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    I've been using insecticidal soap and have had success so far. However it does require multiple applications. Since the battle against pests is never over I'm open to other means that could possibly supplement the soap for more stubborn outbreaks. It never hurts to have more tools to work with.
     
  25. burly

    burly Member

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    Thanks for all of the ideas everyone.

    The name of the oil is Green Earth Horticultural Oil by Nu Gro Corporation.
    If I want a different brand, I will have to look around some more or go to the USA.
    If the branch I sprayed a few days ago looks ok, I will try a few more with the oil.

    Mike
     

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