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Infra-Red Vs. No Infra-Red Who's Done Side by Side Testing w/Same Clones?

Corpselover Fat

Active member
Your chart shows dry mass gains. These parameters cannot be used interchangeably.

The actual study the charts were from had more measurements. They studied leaf expansion and petiole length too. It's not really surprising blue light reduces leaf area especially in high light species. What the study actually says is:

Among the broad spectrum treatments at the higher PPF, increasing BL [blue light] in four increments from 11 to 28% reduced dry mass in tomato, cucumber, and pepper by 22, 26, and 14% respectively, but there was no statistically significant effect on radish, soybean, lettuce and wheat.

[...]

Effects on leaf area paralleled effects on dry mass in all species at both PPFs, indicating that the effects of BL on dry mass were mediated by changes in leaf area. Since LAI is typically highly correlated with radiation capture and since radiation capture is typically highly correlated with dry mass gain, increases in radiation capture are likely
responsible for nearly all of the increases in dry mass. Increased radiation capture can be the result of thinner, or less dense, leaves as indicated by a higher SLA. However, the relativelysmall changes in SLA that occurredwere not adequate to explain the large differences in growth. This suggests that differencesin growth were caused by altered carbon partitioning between leaves and stems, and more rapid coverage of the surface caused by longer petioles
.


And about green light it said

In contrast to the significant effect of BL on dry mass and leaf area, increasing GL from zero to 30% resulted in few significant differences on DM, LAI or net assimilation, and there was no consistent direction among species or PPF levels. Increasing GL increased stem and petiole length in severalspecies,which is consistent with a shade avoidance response. Although GL had little effect on dry mass in these studies, its importance may increase over time as a dense canopy forms.


How these findings on vegging plants would translate to flowering or fruitings plants? Well for cannabis higher blue fraction reduces yield. Kusuma & Bugbee saw pretty much linear reduction in yield with increasing blue fraction. This makes sense. Blue reduces cell expansion so it makes sense that the bud weight will be reduced too.
 

Cerathule

Active member
How these findings on vegging plants would translate to flowering or fruitings plants? Well for cannabis higher blue fraction reduces yield. Kusuma & Bugbee saw pretty much linear reduction in yield with increasing blue fraction. This makes sense. Blue reduces cell expansion so it makes sense that the bud weight will be reduced too.
Yes, it is also filtered out more readily and should grow less massy than red.
White light, with the green percentage being changed. 500ppdf like you spoke of, but a few plants. Tomato is our nearest analogue. Didn't really like it. Lettuce shows a real bias towards blue. Cucumber and wheat liked the green.

But yeah, all plants are the same.
The graph you uploaded and refering to has this description:
screenshot_20221003-192605-2-png.18764818

So, from 7 species, only radish showed a significant reaction towards green light, on this graph.
 

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Ca++

Well-known member
Morphology is certainly effected. Without it, it's ratio throughout the canopy can't be seen. Inhibiting the stretch response.


I wonder if the headstart into flowering that LED plants get, is due to the reduced stretching. A vegetative trait.
Finally found a pot study, and it's not going to be met with much love.

Yes, the far red does cause a stretch response. That is a veg trait. Veg isn't where buds grow.

Increasing far red lowered yields at a linear rate, that make the study look likely. The numbers though.. pretty shocking.

60umol of far red (the higher dose in the trail) was added to 500umol of white. Yield dropped

33%

Extra vegative growth is for lettuce. Not cannabis.


Edit: This is difficult to fit the picture we have of HPS performance. All I have right now, as my brain scrambles for grip, is that the HPS doesn't contain much of the other hindering colours (blue and UV) though I'm running out of listeners now. Despite the volume of evidence available.
 
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Ca++

Well-known member
Thanks bud
I only use far red if I need some stretch. I have not used it until the end. It's just a tool in my collection. These results are shocking though, and some feedback from other users will hopefully follow.

I thought I had found some bars for interlighting, but they were a 50/50 mix of 660 and 730. It made me look at the topic again, and see the bars could actually do more harm than good.

I think a big part of the HPS results, are simply higher evaporation. Which means the top of the plant, gets more food than the rest. A logical situation, that cold lights don't replicate. Though that is another topic
 

Ca++

Well-known member
TBH, The use of 730nm light never quite made sense to me. Nor the ways people incorporate it into their grows. Leaving me shrugging off the whole debate, as I couldn't see the path through it that others seem to.
Now I feel I have seen the light. Reading the same papers again, it all makes sense. Now I have turned the map over, and realised 730nm is for veg. I have looked at the studies that promoted it's use to us, and they have been veg not flowers. Seedlings and lettuce, not cannabis.

Our plant want's to veg, and the processes are held off by something the 730 stops. This single truth, makes the papers read properly.

The side debate here, is moving from the 4% blue of hps, to 20% blue, is a 12% loss of weight. While 30% blue is getting drastic, and beyond that they are physically ill looking.

In line with this debate, is how some more blue dependent grows have seen no change, moving power away from red, into green. If their blue requirement (which can be over 30%) was met, then the rest could be green or red, in just about any reasonable ratio. This is why Samsung made the leafy greens LM301, with low red, that poorly read light manufacturers are giving us for cannabis lighting. Along with the UV&FR LEDs mixed in. Plus any other colour in a paper about anything that grows anywhere.

I'm strongly leaning towards 3000K 301H inter-canopy lighting, with no real desire for 660, and certainly nothing else.


Have I gone insane, Sat here with such revolutionary views?
 

Ca++

Well-known member
It's proving difficult to get a foothold here, or find anyone that has.
iu

This shows our 660nm lighting, is quite good at creating this pfr. This pfr, that reduces the effectiveness of the pr. The pr that holds off vegetative traits. Nowhere on the graph shows how to make pr directly, without making pfr. There are areas where pfr can be made, without pr though. The most efficient wavelength (730nm) for pfr, actually makes no pr. In fact, over ~685nm, we make more pfr than pr.

This is weighing heavily on me. I'm ready to fire off on some 3000K LM301H auxiliary lighting. With no 660 added, as a special request. This will be for intercanopy lighting, where the lack of 660, will lead to more green in my spectrum. Which has better penetration.

Green is another can of worms. It's fairly recent that we decided it works at all. I can't grow on green alone, but white beats the expected blue&red mix the mcree curve suggests. It does seem to be proving itself. Though imagery shows plants don't catch it so easily.
It certainly won't be a great mistake to omit the 660. Mainly because I'm cheap, and will use epistar, making my lights less reliable.

I actually have 120w of QB per meter, going under them on the next run. Just while I settle my thoughts on some bars. The QB is just too energy dense, needing a greater distance from the plants to get even coverage. I will have to mount them downstairs...
 

JKD

Well-known member
Veteran
This is not a grow light or IR, but looks ok for supplementing.

100W COB,
25% of each 610nm, 630nm, 660nm, 680nm

 

Ca++

Well-known member
$300 for 100w?
I'm too tight for that. It would be like shitting a brick. There is no way I'm getting that out, while I'm still conscious. Though it's closer to the topic than my thoughts.

Here we have an odd test, where the FR/NIR is left on 24/7, in order to look at how security cameras might effect a grow
image

The Soy Beans show some elongation the cannabis oddly lacks.
It's hard to see, but some light leaked from the cannabis NIR (lets be clear, it's 840nm in cameras, but extends down to 730) into the no NIR cabinet. You can see how low levels had quite an effect on the plant getting that light leak.

Not a 730nm test, but interesting how little they liked it.
 
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JKD

Well-known member
Veteran
$300 for 100w?
I'm too tight for that. It would be like shitting a brick. There is no way I'm getting that out, while I'm still conscious.
Yes, the pricing is ridiculous.

Interesting test.

Am interested in the ratios used also - I’ve seen Bugbee and some studies from Valoya recommend <5% IR IIRC. I forget the advised ratios R/FR etc. Perhaps those recommendations have evolved since then.
 

Ca++

Well-known member
Yes, the pricing is ridiculous.

Interesting test.

Am interested in the ratios used also - I’ve seen Bugbee and some studies from Valoya recommend <5% IR IIRC. I forget the advised ratios R/FR etc. Perhaps those recommendations have evolved since then.
I can't find anything more to share, that's actually about cannabis. There is no doubt 730nm is useful in some other crops, but other crops, are all I see studied. Except that one paper I started this page with, with the 33% loss in yield. Which was fairly linear except the initial application of very low levels. Where is was as it's worst in terms of light:damage ratio.

I have dug through quite a lot. The only use I see in flower for us, is just after lights out. You can get them to sleep quicker. Which alone is useless, as 12 hours is enough sleep. The gain is getting that sleep done in 10 hours, means a 14 hour day is possible. Normally a 14 hour day gives more weight, but it's expanded low quality flowers. It seems a 14 hour day, with improved sleep, increases flower yield, without that unwanted change in appearance. Pics were offered. What I don't know, is if it was truly as potent as 12 hours light beds. As 14 hour light buds, gain flower weight, but the overall cannabinoid yield is unaffected. Typically, at least.
However, as interesting and unexplored as this remains, it's still not quite the topic here.

Or was it.. I may need to recap.
 

Ca++

Well-known member
So hard to keep on topic though @exploziv :)
So having long since forgotten UV, and now FR, I turned my attention to 660
High THC content showed a strong negative correlation to the photochemical efficiency of PSII
1698000272076.jpeg

Now I'm just scratching at the surface here, but from my deck chair, it looks like 670 gets the PS2 working well, so the plant makes less THC.
Edit: Or they could be saying, high THC makes the ps2 system less effective. It's difficult to really know, as it's just an extract from a paper they want me to buy. The ps2 system is involved with protecting the chlorophyll production, by unloading it. So THC could be taking off the brakes..
Hmm... shouldn't of posted.

I can point to a number of studies, where [engage shock and horror mode] LED lights drop THC yield ~40% but aid cbd production. In fact, plants with more cbd than thc, don't much care about the ps2 problem I'm airing.

I think I just derailed the 660 talk.
 
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Normannen

Anne enn Normal
Veteran
So hard to keep on topic though @exploziv :)
So having long since forgotten UV, and now FR, I turned my attention to 660

View attachment 18908895
Now I'm just scratching at the surface here, but from my deck chair, it looks like 670 gets the PS2 working well, so the plant makes less THC.
Edit: Or they could be saying, high THC makes the ps2 system less effective. It's difficult to really know, as it's just an extract from a paper they want me to buy. The ps2 system is involved with protecting the chlorophyll production, by unloading it. So THC could be taking off the brakes..
Hmm... shouldn't of posted.

I can point to a number of studies, where [engage shock and horror mode] LED lights drop THC yield ~40% but aid cbd production. In fact, plants with more cbd than thc, don't much care about the ps2 problem I'm airing.

I think I just derailed the 660 talk.
sorry for rehashing this past post, but I was rereading it and remembered that THC has peak absorbance at "Chromatographic separation of a hemp extract with individual cannabinoid PDA UV spectra. Top - CBD with UV absorption maxima 207 nm and 275 nm. Middle - THC UV with absorption maxima 209 nm and 279 nm. Bottom – CBCT UV with absorption maxima 212 nm and 280 nm."

so this means that our entourage effect is working against our "high" hopes and there might be cannabioids that are interphering with PS2...
 

Cerathule

Active member
sorry for rehashing this past post, but I was rereading it and remembered that THC has peak absorbance at "Chromatographic separation of a hemp extract with individual cannabinoid PDA UV spectra. Top - CBD with UV absorption maxima 207 nm and 275 nm. Middle - THC UV with absorption maxima 209 nm and 279 nm. Bottom – CBCT UV with absorption maxima 212 nm and 280 nm."

so this means that our entourage effect is working against our "high" hopes and there might be cannabioids that are interphering with PS2...
I don't think so. I remember they all absorb in the UV/blue region. Plants generally don't build photoprotective stuff in the red region of the spectrum. That's why Bugbee could observe bleaching of monochromatic red beyond 700 PPFD-red.
The red correlates most strong with +photosynthesis and +biomass. Cannabinoids occur predominantly on the surface of the plant. Thus, there may be a "dillution-effect" present with buds becoming real heavy on the inside once photosynthates become overabundant. The same mechanism can be shown with high-N fertilizing & lower % THC.
 

Normannen

Anne enn Normal
Veteran
I don't think so. I remember they all absorb in the UV/blue region. Plants generally don't build photoprotective stuff in the red region of the spectrum. That's why Bugbee could observe bleaching of monochromatic red beyond 700 PPFD-red.
The red correlates most strong with +photosynthesis and +biomass. Cannabinoids occur predominantly on the surface of the plant. Thus, there may be a "dillution-effect" present with buds becoming real heavy on the inside once photosynthates become overabundant. The same mechanism can be shown with high-N fertilizing & lower % THC.
You are misunderstanding, what I'm saying is that if there is blue filtering from cannabinoids it will probably affect the PS2 because of excess red, not the other way around. but thanks for confirming my suspicions.
 

Cerathule

Active member
what I'm saying is that if there is blue filtering from cannabinoids it will probably affect the PS2 because of excess red, not the other way around
All PAR preferably excitates PSII over PSI with a few very narrow wavelengths where the dark adapted stoichiometry is equal. Only from >680nm a greater PSI excitation begins to manifest. But in a growtent scenario that doesn't matter at all because plants have developed other means to bring this into balance, after a few minutes of time.
 

Prs2xs

Active member
So hard to keep on topic though @exploziv :)
So having long since forgotten UV, and now FR, I turned my attention to 660

View attachment 18908895
Now I'm just scratching at the surface here, but from my deck chair, it looks like 670 gets the PS2 working well, so the plant makes less THC.
Edit: Or they could be saying, high THC makes the ps2 system less effective. It's difficult to really know, as it's just an extract from a paper they want me to buy. The ps2 system is involved with protecting the chlorophyll production, by unloading it. So THC could be taking off the brakes..
Hmm... shouldn't of posted.

I can point to a number of studies, where [engage shock and horror mode] LED lights drop THC yield ~40% but aid cbd production. In fact, plants with more cbd than thc, don't much care about the ps2 problem I'm airing.

I think I just derailed the 660 talk.
Where might one access the info pertaining to LED's lowering the THC content please?
 

Cerathule

Active member
Where might one access the info pertaining to LED's lowering the THC content please?
Nowhere, the guy is in state of psychotic disorder. Nothing he wrote there makes any sense. I don't know why he uses words that he doesn't understand.
 
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