Light intensities to open Stomata

Discussion in 'Advanced Growing Techniques' started by uscalus storm, Jan 5, 2013.

  1. So I've read that 1/1000th of the suns light is all that is required to open the stomata in plants.
    A quick search gives me 100,000 lux (Lux=lumens per square meter) but only 5-10k with cloud cover. Not really sure what to base it off of, however that leaves roughly 5-10 lumens on this standard. So can we judge that this is the requirement needed in order to disrupt our plants during a night cycle? Of course in the correct spectrum.

    >>I've heard people using green CFL's.

    Anyone have input?
  2. Good question, I have no idea.
    However, I don't think the opening of the stomata is what disrupts the plants night cycle. It has more to do with the plants production of the various hormones that control flowering. I think this requires an accumulation of light to start the biochemical processes.
    Also I believe it is not an issue of light intensity but of duration. I often over the years have had full light from an adjacent room shine into the flower room on the "lights off" period. The need to empty a dehum or fix something, flip a switch etc. might require this. I have never had any ill effects, but only let it happen for a minute or two.
    And, yeah, I have heard of using different color bulbs but haven't read any thing scientific on that.
  3. never heard of stomata, but stoma, according to wikipedia, is "a pore, found in the leaf and stem epidermis that is used for gaseous exchange. The pore is bordered by a pair of specialized [parenchyma] cells known as guard cells that are responsible for regulating the size of the opening. The term stomata is also used collectively to refer to an entire stomatal complex, both the pore itself and its accompanying guard cells.[2] Air containing carbon dioxide and oxygen enters the plant through these openings where it is used in photosynthesis and respiration, respectively. Oxygen produced by photosynthesis in the spongy layer cells (parenchyma cells with pectin) of the leaf interior exits through these same openings. Also, water vapor is released into the atmosphere through these pores in a process called transpiration."

    perhaps they are the same thing?
    as for the stoma, i think they are open/closed depending on temp and humidity levels.

    as quoted... "water vapor is released into the atmosphere through these pores in a process called transpiration."

    if the stoma are inactive/closed due to extreme temps (hi or low) or humidity levels in the air, your ladies will let u know.

    keeping the stoma's open and active is crucial, imo. if nothing is being released, or allowed to sweat out of the leaves, root uptake will also halt, in direct relation.
    as the stoma sweats out 'juice, it allows the water molecules within the plant to pull eachother up the stalk. stuff enters the roots and exits the leaves. if the stoma are closed, and inactive, the roots will also become inactive, unable to pull in new juice.

    i see it as a process. the roots will only pull in nutes/h20 if the plant is able to make room for it, by releasing it, or sweating out, the stoma.

    releasing gases and such through the stoma is something i have found to be very very important.
  4. "Stomata are present in the sporophyte generation of all land plant groups except liverworts. Dicotyledons usually have more stomata on the lower epidermis than the upper epidermis. Monocotyledons, on the other hand, usually have the same number of stomata on the two epidermes. In plants with floating leaves, stomata may be found only on the upper epidermis; submerged leaves may lack stomata entirely"

    And yes, it is an overall process. One reason that in controled rooms (hopefully controlled) we push the limits with higher temps, co2, light and nute levels. We push these up together and control other factors ( rooting medium,humidity, photo period, air movement) to get the fastest growth we can. If we are good or lucky and can find the balance that works best for our particular strain we get grand rewards as those happy little stomachs (stoma, stomata, whatevera) are pumping out and breathing in like god could never have imagined.

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