I can see why sts wouldn't be interested in posting much here anymore. What a waste of good info... I got some objections though. Especially with the main conclusion, realizing it's from 2015.
First, it's a bit funny to see the cherry picked (old) research about wheat (a monocot that happens to have a linear response when increasing ppfd... always nice to see where some parrots got their "wisdom"...) and cucumber (which happens to deviate, according to much more recent and high tech research, more from mccree curves than many other species, especially in the blue region.)
Wheat may sound like weed and grass is a monocot too but no, not great examples by any means.
Sounds based on LDPs, would be less relevant for cannabis. That may is a very big may. It is above all all relative.
Indeed, the
relative effectiveness. People have a real hard time with putting things in perspective.... in dutch called "relativeren". In no way should this lead to recommending 4000k.
Which you can not turn around into "more green and more blue cobs will always increase productivity". It also does no equate to efficiency. And is based on 25 year old research...
Tell that to the growers with the high blue white cobs and there photoinhibited high anthocyanin "colorful" plants...
According to led logic that means running cobs soft make the spectrum even worse...
Exactly. One does not dictate the other especially since you can control them separately.
And why you only need enough blue, or better put, why you only need enough non-red. You don't run red at max, the first to push. You don't have unlimited ppfd. And the lower the ppf, the more sense it makes to spend that low ppf on the best wavelengths.The morphological characteristics of afghanicas/kush and sativas/haze, narrow vs broad leaf drug variety of cannabis are very different. The whole stretch thing is highly overrated. The goal is to grow bud, not an ornamental plant... Much of the stretch I see in the often crappy grows here has a lot more to do with the grower than the type of light used. Just look at the grow of one of the trashtalking fanboys who followed your advice... Ludicrous.
I find it disturbing you posted so much before realizing indoor growing is not about replicating outdoor circumstances but improving them. But hey, better late than never.
Yes because the blue light helps a lot for synthesizing chlorophyl. Many growers who use mh and hps could have told you that. It does not justify using 4000k with red xpe. It at most justifies using high red white cobs with blue xpe when needed. No need to build a veg light and patch its flaws in a crude and ineffective manner. Flower period > veg period.
Especially noticeable with diffuse lighting...
Maybe buried in the incoherent ramblings and quotes, but I missed a few essentials about blue light. Part of the reason its absorbed more are accessory pigments that try to protect the plant against the blue, they pass on energy to be used for photosynthesis but with a big loss.
Blue light is in a way very efficient... in causing photoinhibition and making the blue light even less efficient for photosynthesis, and the red
relatively more efficient. As has been tested and proven with many varieties.
"
In both plants and cyanobacteria, blue light causes photoinhibition more efficiently than other wavelengths of visible light, and all wavelengths of ultraviolet light are more efficient [at causing photoinhibition] than wavelengths of visible light."
https://en.m.wikipedia.org/wiki/Photoinhibition
(
@Greengenes707, I think I posted this one before, perhaps more valuable now...)
View attachment 3698131
Compare that the absorption range of Malvidin (anthocyanin in cannabis) and caretenoids and you will understand why in certain circumstances FR penetrates much better:
Yeah, apart from the high yellow hps isn't that bad when it comes to R and FR.
Now look at the biomass. As wellknown for many years by hid growers, hps puts more meat on the bones. The majority of self proclaimed experts here wouldn't know what good bud and colas look like. The mh may make it seem frostier, but that's at least partly because of the lower biomass where it matters and more frosty leafy bud. If you grow for resin/oil/hash, extreem blue may be the way to go. Efficiency-wise, gpw, total yield, there is a lot to gain from using a more optimal spectrum. I get it's not obvious for every it's (much) better in some cobs, but it rather idiotic to think I can transfer every piece of knowledge people wouldn't believe anyway. Hence, reputable sources, logic, and reason.
As I mentioned in another thread, the whole blue for veg and red for fruits isn't something made up by a few cult members in a forum.
As I pointed out in another thread as well, the plants grows bud despite the horrible spectrums used, not thanks too. It in fact adjusts to fix the mistake in the spectrum, trying to protect it against that blue.
Any of the fanboy clowns reading this, you could potentionally unfuck the photoinhibition and high anthocyanin build up and caretenoid that reduces the effectiveness of blue by increasing FR. Or just pick the right cobs from the start... Took me one look at the philips gen 3 specs.
4000k + 660 sure seems better than the 3500k alone, and may have made sense for 2015... The higher red white cobs like the high cri (90+) and low color temps (3000/2700) contain enough of everything and don't require using cobs and xpe combined to achieve something very similar (read: better).
that is one long report.interesting read tho. think I need to get a life
hell I've seen worse from under the sun and hid, make whatever you want to do- work for you. If you fuck up bad enough, you'll know. (Ie. Me buying spectras)
