rene112388
Well-Known Member
I could show you a plant biology book rather than an experiment as far as pfr I just started getting into this and may just review that chapter before Ispeak
Effects of vegging under flower/red light.
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Devildenis69
Well-Known Member
Hey man, are you sure about that ?
I haven't ever used blue leds personnaly, but I've seen few grows using them during veg and plants were always very short, it's promoting secondary growth ... and I believe as you that it has the same effect during flowering
churchaze: a very important point red colour vs warm temperature color ... I added some 660nm during my stretch, it stopped 2 days later ... I haven't ever grown these strains, so I don't know their normal stretch period, but doesn't seem to be a coincidence ...
I have a little doubt about the blue color and Pr/Pfr ... never heard about blue promoting roots growth ... I've heard something dealing with cytokines ... really not sure about this one ...
also at 450nm, Pr ratio seems to be higher, which shouldn't inhibit stretch ...
churchhaze
Well-Known Member
The distinction is important because if some 450nm photons are converted to 600nm, the color temperature will be lower, but 600nm causes Pfr/Ptot to be significantly lower than 660nm, so it misleads many people into thinking red causes stretch... because 600nm is "warmer" than 450nm, but no amount of 600nm will make it red.
Ghost of Davy Jones
Well-Known Member
LIGHT HAS ZIP TO DO WITH SEX BUDDY.
![[]D[][]\/[][]D](/data/avatars/m/985/985221.jpg?1521126417){kind=avatar}
[]D[][]\/[][]D
Member
From what I have determined, unless you want stretchier plants, you want to use red light throughout the process. An excess of red light will also transition your plant into flowering faster. You only want a small amount of blue light, less than 10%, if you want very short bushy plants.
Here's a study explaining the effect of red light and plants:
http://flor.hrt.msu.edu/assets/Uploads/Red-light3.pdf
From the publication: Many plants grown under only red light, such as plants grown indoors under only red LEDs, have a stretched, elongated appearance; the leaves are thin and large and plants become tall. In most cases, plants grown under only red light do not have desirable growth characteristics. However, when a relatively small amount of blue light is added to red light, extension growth of plants is inhibited. Therefore, plants grown indoors with 80 to 90 percent red light and 10 to 20 percent blue light are quite compact, with smaller leaves and shorter stems.
Here's a more extensive study into why that is: https://digitalcommons.usu.edu/cgi/viewcontent.cgi?article=5650&context=etd
Interesting conclusions:
At a PPF of 500, increasing blue light from 11 to 28 % decreased dry mass in tomato, cucumber, radish, and pepper, but there was no significant effect on soybean, lettuce and wheat. At a PPF of 200, dry mass significantly decreased only in tomato across the blue light range. Effects on leaf area paralleled effects on dry mass in all species at both PPFs, indicating that the effects of blue light on dry mass were mediated by changes in leaf area
Also note: The 3500k spectrum / HPS seems to be the best producer according to the study data. Probably due to it's excess in the red spectrum and it's super high intensity.
Here's a study explaining the effect of red light and plants:
http://flor.hrt.msu.edu/assets/Uploads/Red-light3.pdf
From the publication: Many plants grown under only red light, such as plants grown indoors under only red LEDs, have a stretched, elongated appearance; the leaves are thin and large and plants become tall. In most cases, plants grown under only red light do not have desirable growth characteristics. However, when a relatively small amount of blue light is added to red light, extension growth of plants is inhibited. Therefore, plants grown indoors with 80 to 90 percent red light and 10 to 20 percent blue light are quite compact, with smaller leaves and shorter stems.
Here's a more extensive study into why that is: https://digitalcommons.usu.edu/cgi/viewcontent.cgi?article=5650&context=etd
Interesting conclusions:
At a PPF of 500, increasing blue light from 11 to 28 % decreased dry mass in tomato, cucumber, radish, and pepper, but there was no significant effect on soybean, lettuce and wheat. At a PPF of 200, dry mass significantly decreased only in tomato across the blue light range. Effects on leaf area paralleled effects on dry mass in all species at both PPFs, indicating that the effects of blue light on dry mass were mediated by changes in leaf area
Also note: The 3500k spectrum / HPS seems to be the best producer according to the study data. Probably due to it's excess in the red spectrum and it's super high intensity.
Bad Karma
Well-Known Member
Do some research, actually try it out, and you'll see differently.
Ghost of Davy Jones
Well-Known Member
i'll poke around.
CobKits
Well-Known Member
Dustin Jenson
Member
No plant is ever 100% any sex until it's done growing. I've had females masturbate so hard you would think they were a male, or at least a full-fledged hermie. It's rare, but never say never.