The Ideal spectrum.

nachooo

nachooo

Well-Known Member
ChiefRunningPhist said:
Noted. FR during lights on, not only at end-of-day. Good find!
Click to expand...
Yes, and it seems , at least with tomato plants, that Red/Far red ratio can be higher than sunlight and still obtain benefits of far red. what I mean is that we dont need too much far red..so less problems with elongation. What we have to find is what Red/Far red ratio is the best in veg and flower conditions..and how to translate it to practical growers conditions…. I mean..how much Red is provided by our lamps…(different situations in every grower….diferent Kelvin..CRI etc...) and then add exactly the needed Far red in order to obtain the correct ratio. A light company can do it easily cause they have measuring tools and sometimes.. sharp minds….but for us...poor mortals…. the only way is guess and experiment….
 
TEKNIK

TEKNIK

Well-Known Member
Different strains react differently n different ways when it comes to this. There is no correct answer, it causes some strains to stretch more than you would like but with others they seem to love it. Far red creates a shade response to make the plants want to stretch out, it also helps 660nm work better as per the Emerson effect. The ratio of 660nm and 730nm depends on what you are growing, only way to determine what works best is to have a tunable spectrum. I think 730nm works better when the spectrum is more balanced. 730nm can also be used in Veg stage too to control how much stretch you want.
 
OneHitDone

OneHitDone

Well-Known Member
nachooo said:
Yes, and it seems , at least with tomato plants, that Red/Far red ratio can be higher than sunlight and still obtain benefits of far red. what I mean is that we dont need too much far red..so less problems with elongation. What we have to find is what Red/Far red ratio is the best in veg and flower conditions..and how to translate it to practical growers conditions…. I mean..how much Red is provided by our lamps…(different situations in every grower….diferent Kelvin..CRI etc...) and then add exactly the needed Far red in order to obtain the correct ratio. A light company can do it easily cause they have measuring tools and sometimes.. sharp minds….but for us...poor mortals…. the only way is guess and experiment….
Click to expand...
I believe you are 100% on the correct path. The issue is that the wheels start coming off of the 'Efficiency" Bus when you start trying to widen the spectrum.
Making something like CMH much more appealing and then the Old Faithful that still seems to be king of the hill in flower production - HPS :peace:
 
OneHitDone

OneHitDone

Well-Known Member
TEKNIK said:
Different strains react differently n different ways when it comes to this. There is no correct answer, it causes some strains to stretch more than you would like but with others they seem to love it. Far red creates a shade response to make the plants want to stretch out, it also helps 660nm work better as per the Emerson effect. The ratio of 660nm and 730nm depends on what you are growing, only way to determine what works best is to have a tunable spectrum. I think 730nm works better when the spectrum is more balanced. 730nm can also be used in Veg stage too to control how much stretch you want.
Click to expand...
This would be a good opportunity for you to flex some knowledge muscle.
Let's just break it down - how would one match the Red:Far Red ratio that is in HPS using LED's?
None of this "tunable" vague answer stuff - we KNOW HPS WORKS......
 
TEKNIK

TEKNIK

Well-Known Member
Hps has far red in many different wave lengths, LED's are good in the 450-660nm range, hps cmh hid go beyond what LED's can do unless extra money is spent. 750nm may have extra benefits that we do not know about also, 750nm is generally not present in LED lights. I really think that we are missing important information regarding all spectrums as general blend and the reactions they have working together. I don't have the answers, more experiments need to be done.
 
OneHitDone

OneHitDone

Well-Known Member
Well brother @nachooo , that article clearly highlights why many see more "praying" in led plants. It is clearly the results of a wonky spectrum

"Petiole angle (upper angle between petiole and stem) increased with decreasing PSS in both experiments, resulting in more horizontally oriented leaves at low PSS (Figure 1B). The EOD-FR treatment hardly affected the petiole angle. Decreasing PSS from 0.88 (0.87 in EXP2) to 0.80 increased the total leaf area per plant by approximately 3% (EXP1) and 21% (EXP2) (Figure 1C) but decreasing PSS below 0.80 had no further effect on total leaf area. The EOD-FR treatment did not increase total leaf area, compared with the other treatments without supplemental FR (PSS 0.88; Figure 1C). The area of individual fully grown leaves (Leaf number 2 and 3) showed comparable results to that of total leaf area, and leaf length increased with decreasing PSS in both experiments (Supplementary Table S3). The leaf mass per leaf area (LMA) was lower for the plants treated with additional FR or EOD-FR (Supplementary Table S4)."
 
nachooo

nachooo

Well-Known Member
TEKNIK said:
Different strains react differently n different ways when it comes to this. There is no correct answer, it causes some strains to stretch more than you would like but with others they seem to love it. Far red creates a shade response to make the plants want to stretch out, it also helps 660nm work better as per the Emerson effect. The ratio of 660nm and 730nm depends on what you are growing, only way to determine what works best is to have a tunable spectrum. I think 730nm works better when the spectrum is more balanced. 730nm can also be used in Veg stage too to control how much stretch you want.
Click to expand...
Not exactly...seems that benefits for Far red addition are bigger when you are using a not balanced spectrum like Blue/red.led lamps. A wider and more balanced spectrum like a Warm White 3500 K has some far red in it and the benefit of adding far red is less. @Randomblame posted a very concise study that stated that… Anyway the benefits appear in the two options

I was taking mainly about using Far red not as EOD or stretch control...using it instead as a growth enhancer adding it to main spectrum all day..this is related to Emerson effect but not only that.. also as an stomata control influence and phytochrome can act maybe as humidity sensor...(interesting theory link below)

http://www.international-agrophysics.org/Atmospheric-moisture-controls-far-red-irradiation-a-probable-impact-r-non-the-phytochrome,104140,0,2.html
 
nachooo

nachooo

Well-Known Member
OneHitDone said:
Well brother @nachooo , that article clearly highlights why many see more "praying" in led plants. It is clearly the results of a wonky spectrum

"Petiole angle (upper angle between petiole and stem) increased with decreasing PSS in both experiments, resulting in more horizontally oriented leaves at low PSS (Figure 1B). The EOD-FR treatment hardly affected the petiole angle. Decreasing PSS from 0.88 (0.87 in EXP2) to 0.80 increased the total leaf area per plant by approximately 3% (EXP1) and 21% (EXP2) (Figure 1C) but decreasing PSS below 0.80 had no further effect on total leaf area. The EOD-FR treatment did not increase total leaf area, compared with the other treatments without supplemental FR (PSS 0.88; Figure 1C). The area of individual fully grown leaves (Leaf number 2 and 3) showed comparable results to that of total leaf area, and leaf length increased with decreasing PSS in both experiments (Supplementary Table S3). The leaf mass per leaf area (LMA) was lower for the plants treated with additional FR or EOD-FR (Supplementary Table S4)."
Click to expand...
I was thinking the same while was reading it...
 
nachooo

nachooo

Well-Known Member
TEKNIK said:
Because 730nm or FR is starting to produce heat in a different way it will effect humidity and stomatal. There is definitely a link between stomatal and FR. If you look at a hps is has very high amounts of green that is responsible for stomatal, and high amounts of FR
Click to expand...
Is not only the heat...it seems that affects stomata throught other mechanism...phytochrome changes..etc...
 
TEKNIK

TEKNIK

Well-Known Member
It's clear the purple leds lights are lacking after not so many years of experiments, next we will work out what is lacking in white LED's. I believe we need to mimic nature but I could be wrong also. It's possible that by trying to mimic nature with LED's production will be reversed and noone wants that.
 
jjng5

jjng5

Well-Known Member
trojanvirus said:
here's a read you might enjoy.
Click to expand...
Interesting read @trojanvirus -- and we were all told that green light was totally wasted. Here we find out that it provides penetration to the lower chloroplasts in smaller quantity more so than added red's or blue's once initial chloroplasts are filled / saturated. Am I understanding that right? So some green light is beneficial in very small amounts once you're on the higher watt / sq foot intensity side of the scale. Is that how you understand things?
 
TEKNIK

TEKNIK

Well-Known Member
A hps is low in red and blue light, can't deny that they work great though. My belief is that because they are high in green light this opens up stomatal to absorb any photons they can get. Red and blue light is useless unless the plant can accept the photons produced. I worked this out a long time ago long before people started to use COBs to grow with.
 
jjng5

jjng5

Well-Known Member
TEKNIK said:
Without green light the plants can only absorb so many photons is my understanding, plants need full spectrum to absorb the peak spectrums properly.
Click to expand...
I understand that part, but then the question becomes "how much?". Am I right? It's all about dosing in quantities that matter. Not even quantities so much as ratios once we assume enough quantity. That's what I'm trying to understand. I get that red light is prioritized, then blues/white light, with green light being last once the first two are satisfied first.

For example, I look at what I have, per flower tent = (2) HLG324's @ 3500k - ~330watt total, (4) QB144's @ 3000k ~ 250watt total, and (2) QB96's customized [64 High power White, 16 Red (660nm) and 16 Deep Red (660nm)] ~390watt total. That breaks down like this:

330w - 3500k
250w - 3000k
390w - 67% whites/blue 33% reds/far-reds
= 970 watt total

= 60% mid-spectrum white/greens, 40% red/far red

What I'm trying to decide is if that's spot on or imbalanced based upon the data? Obviously quantity is there at ~39 watt/sq foot of LED QB's. What I'm wondering is if I've properly balanced the ratios in the most efficient way.
 
TEKNIK

TEKNIK

Well-Known Member
Green light is one of the lowest efficiencies in the PAR spectrum, this is also why I think PAR is not a good way to measure the efficiency of a grow light. The math doesn't add up.
 
TEKNIK

TEKNIK

Well-Known Member
I honestly do not believe in an ideal spectrum, I think it needs to change to mimic nature. It probably doesn't need to exactly mimic nature but I think it needs to have high amounts of blue and green light mid way through the day with heavier reds when first turned on and when it is finishing for the day.
 
You must log in or register to reply here.
Top