OK, so you are saying... if you had two identical plants (clones) both at 9 hours night length (say in different tents), and both under the same wattage LED lights, the plant closer to the LEDs would reveg sooner?
Yes, these are the photo receptors that control what hormones, like auxins and gibberellins are produced.
Both hormones are produced 24/7. Auxin production is highest at first light and through the day. Gibberellin production increases during the dark hours. How light interruption floods auxin and slows gibberellin effecting daily net balance. Light effects Pr, Pr effects hormones, hormones effect growth. Just how much you want to zoom in on the reactions.
Kelvin is a spectrum average of all colors emitted where nano meters is a wave length within that spectrum. Light spectrum effects growth. 6500 kelvin, being summer blue heavy spectrum, will promote horizontal growth. 2500 kelvin, being a fall red heavy spectrum, will promote vertical growth. Adding blue will slow early flower transition and stretch. Adding red increases stretch and speeds the transition from veg to flower. Natural response in nature. Equatorial plants do not have a significant shift in day length. Different genetics and different micro climates all flower at the same time. Spectrum is there primary trigger.
Light is potential glucose and glucose is growth. You can only work with what you got. The plant can only use what the other 8 parameters support. Push the DLI to the next limiting factor will optimize growth into reveg. Pushing beyond will stress the plant slowing growth. She will tell you if you are pushing too hard. Just have to pay attention.
Yes. Increase the distance from the light and the amount decreases in much greater amounts than many think. As one on-line explanation put it: "...every time you double your distance from the light to your subject, you lose 75 percent of the light."
Which is pushing it to the maximum possible. Go past the max that the plant is able to handle then a decrease starts.
Apparently gibberellin precursors are produced during the day, and gibberellin mainly at night.
I was just pointing out that Pr/Pfr are controlled by the red spectrum, so one would prefer a strong rather than weak red spectrum at night to prevent flowering or reveg, as would be available with a daylight spectrum LED bulb.
Do you agree that if all other parameters are being met, light pretty much drives all plant physiology?
I do.
Completely agree on almost all points. The only difference is the use of 6500 vs 2700 effect on red spectrum. LEDs are more of a bell curve of spectrums where florescence are three distinct spikes of color. Comparing 2700K to 6500K does not changing the green or red spikes. Using 6500K simply increases the blue spike. So daylight spectrum is not reducing red but simply increasing blue.
If I am interpreting these charts correctly, it looks to me like the brightness at 666nm for the fluorescent is very low as compared to LED daylight spectrum (5000K). The Pr building up at night (for flower) is immediately converted to Pfr with a flash at 666nm.Completely agree on almost all points. The only difference is the use of 6500 vs 2700 effect on red spectrum. LEDs are more of a bell curve of spectrums where florescence are three distinct spikes of color. Comparing 2700K to 6500K does not changing the green or red spikes. Using 6500K simply increases the blue spike. So daylight spectrum is not reducing red but simply increasing blue.
2700K
5000K
You are comparing 5000k LED to 2500k florecent. Apples and oranges. Neither light option is an LED. We are comparing a 2700k florecent to a 5000k florecent. Any LED, no matter the kelvin, is going to be a fuller bell shaped spectrum than any florecent.If I am interpreting these charts correctly, it looks to me like the brightness at 666nm for the fluorescent is very low as compared to LED daylight spectrum (5000K). The Pr building up at night (for flower) is immediately converted to Pfr with a flash at 666nm.
5000K - daylight spectrum LED
Yes, I know. Sorry... I was slipping into my own personal bias here. I use LED... never used a fluorescent. So, I understand OP was able to get a high-wattage CFL grow light. All good. For night interruption, all you need is a low-wattage, daylight spectrum LED which are very cheap. But this isn't a "grow light".
Yes, my chart is relative spectrum, but yours show absolute irradiance. Anyway, what counts is the wattage and therefore brightness. The color is the wavelength (frequency), and the brightness is the amplitude.
Overall they are looking good and good progress....lotsa goodness
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