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Dendrobium vexillarius and supplemental light

Discussion in 'Orchid Culture' started by Chuck-NH, Jan 17, 2021.

  1. Chuck-NH

    Chuck-NH Well-Known Member

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    Location:
    New Hampshire, USA
    One of the problems with a greenhouse that is far north of the equator is less daylight in the Winter months. Most years I have made it to longer days quite fine, but this year it has been very cloudy since late October and I noticed that the high light loving, cool growers were not blooming well and new growths were not as compact as in the past.

    In December I hung a couple cheap LED grow lights to experiment with supplemental lighting. I got one with folding light panels so I could angle it to get the best coverage. I do believe I am seeing some improvement, at least in the flower color of one of my Dendrobium vexillarius.

    First photo is of one the lights and plants around it...did move a few plant further away as they were staring to burn a little.

    DB92A971-9A6A-4EDB-8033-91E90CCB1878.jpeg

    The next photo is of a typical Dendrobium vexillarius var. microblepharum which is a bright, clear orange. The color on this plant has been constant even after exposure to supplemental lighting.

    9016BAB5-E0FD-49C8-93E9-53FC2745647B.jpeg

    I don’t have a before photo, but the red form of microblepharum opened at the same time as the orange and I couldn’t tell them apart. After a few weeks of exposure, I can certainly tell the difference now. For those who might think it is simply aging of the blooms, the new buds opening are starting out red. Please note as well that the photos on my computer look a lot darker red than they do for the uploaded photos...strange?

    FE6E789B-AEF4-4D63-AFBD-307978020DC7.jpeg
     
  2. Ray

    Ray Orchid Iconoclast Supporting Member

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    While I cannot speak to any individual plant, in general, the anthocyanins that lead to red flower color develop better in cooler and brighter conditions.
     
  3. Chuck-NH

    Chuck-NH Well-Known Member

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    Agreed...also notice that with pigment in the foliage as well.