LED and BUD QUALITY

[Prawn Connery]

I'm not rewriting physics, but look at your special values. You are just inventing some units, miscalculating others, and others are just downright backwards. That's quite a collection.

Which "special values" are you referring to?

What "unit" did I just invent?

Which ones did I miscalculate?

Which values are backwards?

Please, be specific so we can address all these points.

 

[Normannen]

Awe grey you so Cray……fish

Oh Crab! I almost mist out on all the fun!

 

[Prawn Connery]

If warm air puts 2 units into a leaf, by encasing it, that is a unit from each side.

Both may put a joule into the leaf, but one does it by encasing the leaf, and the other does it from one side. Using something like twice the energy, in photons.

If you want IR to put that in from one side, than both units are coming through the light receptive part of the plant. The transpiration side non.

Is that how things work? Hmm. Let's think about this for a minute.

There are chloroplasts throughout the leaf – even on the stomata side (though less densely distributed)

IR reflects and diffuses, so some of it will reach the other side of the leaf.

Indeed, IR penetrates deeper than convection, so has potential to reach parts of the leaf that convection doesn't.

But all this aside, how does that address my question about optimum leaf temperature?

 

[maryjaneismyfre]

Im running my first LED room now, side by side with an identical room except for light, running side by side on same nutes etc...Sealed room, CO2 at 1000-1200ppm, light is 1000ppfd to 1200ppfd. Same wattage of light I think or slightly less in LED room, PPFD is lower in HPS room. I've run the CMH vs HPS vs checkerboard CMH/HPS and CMH is just considerably less efficient so once dialed it you will always get more yield out the HPS, even the checkerboard for flowering wasn't worth it. The LED's we are running are the nanolux bars, with RED bars for earlier in cycle adding about 200ppfd of red. I run many greenhouses so have the sun, and sun plus little HPS and sun plus lots of HPS to compare.

I'd say the LED room is killing it so far. Patently obvious. Sun and all its mixes comes second as you can't replace the sun. Sun once finished with mid summer crop will look better than LED as you can't compete with 2000ppfd of sunlight. Once you have enough decent light, viroid is affecting things FAR more than light is, I can spot the two infected plants in a room among 800 clean ones..its a process getting clean LOL...

Working with (mainly) clean plants now, I like what i am seeing with the LED, like what I smell..I think the scale will also be very happy.

 

[Prawn Connery]

"That's really all I'm asking. Does it matter how a leaf reaches a certain temperature? Or does it matter more that the leaf is maintained at an optimal temperature?"

well, Prawn, may i shrimply say both matter. some large greenhouse operations have discovered that their non-IR heating systems, while adequately heating the entire space, are failing to precisely control the temperature at the canopy within optimum parameters.

some have installed supplementary IR systems targeting the canopy that creates a more stable microclimate in the canopy that increases yield and enhances phenol production.

phenols are secondary metabolites, of course.

with any plant, we have a finite temporal span in which to grow the plant. the more time during that span that conditions are kept within an ideal band of parameters the better the end product will be.

Effects of Infrared Radiation on Eggplant (Solanum melongena L.) Greenhouse Cultivation and Fruits’ Phenolic Profile

The implementation of Infrared (IR) radiation in heated greenhouses possesses the advantage of high directional control and focused compensation of energy losses, appropriate for creating local microclimate conditions in highly energy-consuming systems, such as greenhouses. Moreover, it can...

www.mdpi.com

editing to say that before someone says eggplants are not cannabis that I've already experienced that epiphany.

Thank you for the study. I just read it. There are a few things I couldn't clarify from what was published, so perhaps we need to talk through these first.

* Did the IR lamp produce other wavelengths? IE, PAR or far red? Most heat lamps do, in fact, produce visible light. I would like to have seen a spectrograph for those experiments to see exactly what the light was like in both greenhouses. The experiment makes mention of 4x "blown bulb lamps" (1kW total, so 250W each), so it is not unreasonable to assume they used 1kW of halogen. I could be wrong, but who knows?

Did they use one of these? This is really the elephant in the room and I don't know why it hasn't been addressed.

* Phenolic compounds is an interesting one, as higher temperatures can facilitate oxidation of secondary metabolites. It is worth noting that eggplant fruit hang low, below the canopy, and that the air temperature inside the non-IR greenhouse was significantly lower – especially where the fruit where growing (I would assume). Did this have any effect on secondary metabolites after they had been produced? We know, for example, that higher temperatures (~30C) are near optimal for cannabis dry yields, but lower temperatures (~25C) are a better compromise of dry yield vs terpene yield.

* It appears for the most case the canopy temperature was higher in the IR greenhouse than the non-IR greenhouse. On some days it was quite close, but on others it appears the IR grow had more stable and slightly higher temps.


Nonetheless it's an interesting study. But I'll hold my opinion until I know what type of IR bulb they used. More PAR is more PAR, after all.

 

[Prawn Connery]

And here is another study. It is a long one, but more recent, and they grew tomatoes in the Netherlands.

https://www.sciencedirect.com/science/article/pii/S1537511023000788#sec2

For the TLDR crowd, here is a picture. There is a direct correlation between yield and PAR no matter how the greenhouses were heated (bottom left vs top right).

PAR, it appears, is king. No surprises there.

 

[CannaT]

IR is around 50% of sun spectrum that hit the surface of earth.
Its more importent than led producers think it is...so after all its look like full spectrum lack of far red.

 

[Ca++]

The rate of energy transfer is the perception of heat. The more energy transfer over a given amount of time, the "hotter" it feels.

Energy will always flow from a higher source to a lower source (transfer gradient). When the high energy source contains a lot of energy compared to the low energy source, then the gradient is steeper and the rate of transfer is potentially faster.

The rate of transfer can be impeded by the transfer mechanism itself. Convective transfer is (generally) slower than conductive. Radiative transfer depends on a lot of variables. Radiation can travel from the sun to earth almost unimpeded because it travels through a vacuum, but once it reaches earth's atmosphere, water, air and other molecules start to scatter (Raleigh Scatter explains why the sky is blue) or absorb that radiation.

So UVC radiation is emitted by the sun in large amounts, but does not reach earth because all of it is absorbed by our atmosphere. That is energy that is not transferred to the earth's surface (you and I) and that is lucky, because UVC carries so much energy it would kill us!

When considering radiative energy transfer, some photons carry higher energy than others but may be absorbed at a lower rate, which means the transfer of that energy is slower, and thus feels "cooler".

Visible light carries more energy than infrared. But visible light will pass through water molecules while IR interacts with it, which means IR will "heat" water faster than visible light even though it is less powerful (longer wavelength; Plancks Law) and even if there are fewer photons of IR available.

Remember than once a leaf is heated by IR, the energy that is transferred from the light source via radiation will then transfer within the plant via conduction – mostly via water molecules.

So radiative and convective energy (heat) both end up as conductive energy within the plant cells.

What I want to know is, why would that initial energy source (IR transfer vs ambient temperature/convective transfer) trigger a different photosynthetic or photomorphogenic response in plants if it all ends up as the same type of conductive "heat" inside the plant?

Kinetic energy is kinetic energy, after all.

I didn't see a question about leaf temperatures. You said you want to know how different routes to the end temperature, could be having different effects.


28c is a nice temperature. To get there, an LED room might need to be 31c. A couple of C difference between what indoor plants like, is common.

 

[Ca++]

IR is around 50% of sun spectrum that hit the surface of earth.
Its more importent than led producers think it is...so after all its look like full spectrum lack of far red.

There isn't much support for IR use, from a photo aspect. For a while we looked at 730nm, but it's seen as influential more than a growth colour. The heat angle is certainly real, but not something we are likely to correct with LEDs. If we want heat, an LED isn't a viable source. They like keeping cool. This is why a lot of people use incandescent lamps to produce IR. The straight line graph above, is a good representation of a filament lamp.

 

[greyfader]

There isn't much support for IR use, from a photo aspect. For a while we looked at 730nm, but it's seen as influential more than a growth colour. The heat angle is certainly real, but not something we are likely to correct with LEDs. If we want heat, an LED isn't a viable source. They like keeping cool. This is why a lot of people use incandescent lamps to produce IR. The straight line graph above, is a good representation of a filament lamp.

all electromagnetic radiation has vibrational-rotational qualities. i'm looking at research that shows IR having profound effects on plant cells and tissues aside from heat. such as causing migration and rotation of cell contents. i'll show it soon. i need a little more time to read and think about it.

 

[Prawn Again]

I didn't see a question about leaf temperatures. You said you want to know how different routes to the end temperature, could be having different effects.

With respect, you're being disingenuous. If there was no mention of leaf temps (there was: post #2346 and subsequent posts after that), then why have you – yourself – been referring to it?

IR is photons. Hot air isn't. Hot air won't excite a molecule to the same degree. The hot air fitting your model of conduction. While the light particles are a much lower grit paper. Higher spikes. Greater momentary interactions. Only after dissipation, does the picture get more like you describe. Both may put a joule into the leaf, but one does it by encasing the leaf, and the other does it from one side. Using something like twice the energy, in photons.

This is different for the leaf. As it would be for you, standing with the sun on one side, or in a warm dark room.

This is just logical thinking though. Showing two different routes, getting to the same point. Explaining how there could be differences there, if there actually were any. Reasons like water movements within the leaf, which would tie in with morphology, more than most other explanations.

And this stuff is just plain made-up. I asked you to point out specifically where I had said any of these things, but you couldn't. Because I didn't.

I'm not rewriting physics, but look at your special values. You are just inventing some units, miscalculating others, and others are just downright backwards. That's quite a collection.

I'm all for having an honest discussion – honest sometimes means being wrong in good faith – but if you're going to deliberately embellish the truth, then you can't expect me to take you seriously.

And yes, my other account appears to have some issues, so I'm using this one for now . . .

 

[Ca++]

Look forward to that.
I have looked at harmonic influences, but couldn't make anything stick. I can't shake the idea though.

 

[maryjaneismyfre]

 

[Prawn Again]

all electromagnetic radiation has vibrational-rotational qualities. i'm looking at research that shows IR having profound effects on plant cells and tissues aside from heat. such as causing migration and rotation of cell contents. i'll show it soon. i need a little more time to read and think about it.

I was looking at this the other day, as the only obvious difference I could see between convective heating and IR is that convective heating causes the whole molecule to vibrate whereas electromagnetic radiation imparts different vibrational-rotational qualities on electro-magnetic bonds causing them to "stretch" or "spin" in different ways. This is how a microwave imparts energy on a water molecule faster than other molecules, causing the water inside an object to heat first.

Just how this metabolic warmth that speeds up organic chemical processes causes different reactions inside the plant I have not been able to find.

This is partly what I was looking for. The animated version is here: https://www.quora.com/When-microwav...emperature-If-not-what-else-is-going-on-there

Here's another example: https://www.quora.com/When-heating-...n-they-move-back-and-forth-Is-that-observable

 

[Prawn Again]

IR is around 50% of sun spectrum that hit the surface of earth.
Its more importent than led producers think it is...so after all its look like full spectrum lack of far red.

IR is all around us. Everything above 0 degrees Kelvin emits infrared radiation. Infrared covers a huge range of the electromagnetic spectrum, with different wavelengths having different properties.

LED fixtures do emit IR. In fact, even the most efficient ones are only converting about 60% of their energy to PAR. The other 40% is converted to heat, mostly conductive that ends up as convective heat, as excess energy escapes through the diode solder pad to the trace, then through the PCB and into the heatsink, where air movement ducts it away.

However, a smaller amount of IR is emitted by the diode itself and basically any part of the fixture that is warm to touch is also emitting IR in the form of black body radiation. The "hotter" an object is, the more IR and the shorter the wavelength.

If you heat a piece of metal it will give off IR. The more you heat it, the more IR and the shorter the wavelength (higher energy photons) until it starts to glow red, orange, yellow, blue etc.

The problem with referring to "IR" or infrared is that it extends all the way from around 750nm up to 1mm (1000um) – a huge range – so even if we worked out what effect "IR" was having on plants, we would then need to narrow it down to specific wavelengths and what they were actually doing.

 

[CannaT]

IR is all around us. Everything above 0 degrees Kelvin emits infrared radiation. Infrared covers a huge range of the electromagnetic spectrum, with different wavelengths having different properties.

LED fixtures do emit IR. In fact, even the most efficient ones are only converting about 60% of their energy to PAR. The other 40% is converted to heat, mostly conductive that ends up as convective heat, as excess energy escapes through the diode solder pad to the trace, then through the PCB and into the heatsink, where air movement ducts it away.

However, a smaller amount of IR is emitted by the diode itself and basically any part of the fixture that is warm to touch is also emitting IR in the form of black body radiation. The "hotter" an object is, the more IR and the shorter the wavelength.

If you heat a piece of metal it will give off IR. The more you heat it, the more IR and the shorter the wavelength (higher energy photons) until it starts to glow red, orange, yellow, blue etc.

The problem with referring to "IR" or infrared is that it extends all the way from around 750nm up to 1mm (1000um) – a huge range – so even if we worked out what effect "IR" was having on plants, we would then need to narrow it down to specific wavelengths and what they were actually doing.

Im talking about that plants recive for milion of years sunlight on their leafs that is 50% IR and 50% visible light...and Leds are mising that in high amount.
Thats why plants dont behave naturaly under leds...have brown spots and other symptoms that when grown under Hids dosent have.
So in reality best led board will be 1 by 1 IR /Full spectrum diodes...but it will be much hotter than led board we have atm.

 

[Prawn Again]

Im talking about that plants recive for milion of years sunlight on their leafs that is 50% IR and 50% visible light...and Leds are mising that in high amount.
Thats why plants dont behave naturaly under leds...have brown spots and other symptoms that when grown under Hids dosent have.
So in reality best led board will be 1 by 1 IR /Full spectrum diodes...but it will be much hotter than led board we have atm.

Except that's not true. The "brown spots" you are referring to are likely Ca deficiency or lockout – mostly likely deficiency from lack of transpiration, possibly exacerbated by lockout due to cation exchange if you are growing in coco.

The reality is there are plenty of people growing great weed under LED and have been doing so for many years.

Plants behave perfectly fine under LED.

In any case, plants don't photosynthesise under infrared light. Plus think about it: all those leaves that are not in direct sunlight are actually shaded from IR, so how does that work? Many plant varieties grow under shade canopies that reflect IR and block it from the lower canopy.

I'm open to the idea of infrared having an effect on plants, I'm just waiting for someone to tell me what that effect is.

And I won't hear a word about how badly LED grows because it's simply not true. If you can't grow great weed under LED, then there is a reason for it that is not related to LED.

 

[CannaT]

Except that's not true. The "brown spots" you are referring to are likely Ca deficiency or lockout – mostly likely deficiency from lack of transpiration, possibly exacerbated by lockout due to cation exchange if you are growing in coco.

The reality is there are plenty of people growing great weed under LED and have been doing so for many years.

Plants behave perfectly fine under LED.

In any case, plants don't photosynthesise under infrared light. Plus think about it: all those leaves that are not in direct sunlight are actually shaded from IR, so how does that work? Many plant varieties grow under shade canopies that reflect IR and block it from the lower canopy.

I'm open to the idea of infrared having an effect on plants, I'm just waiting for someone to tell me what that effect is.

And I won't hear a word about how badly LED grows because it's simply not true. If you can't grow great weed under LED, then there is a reason for it that is not related to LED.

Ca+ is that your new acc ?

I grow great weed under leds,hps and led/hps still I prefere weed grown with bit of Hids...dont cry baby.

 

[Normannen]

Look forward to that.
I have looked at harmonic influences, but couldn't make anything stick. I can't shake the idea though.

That's because reality is Square harmonics

 

[Prawn Connery]

View attachment 18942268
Ca+ is that your new acc ?

I grow great weed under leds,hps and led/hps still I prefere weed grown with bit of Hids...dont cry baby.

No. But it looks like I can use my account again.

I'm not sure I follow you. You said this:

Thats why plants dont behave naturaly under leds...have brown spots and other symptoms that when grown under Hids dosent have.

So what makes you think only LED plants have Ca deficiency? And in what way do plants not "behave naturally" under LED?

Now you're saying you grow fine under LED???

You guys say stuff and then contradict yourselves. How is anyone supposed to follow you?

And of course the sun imparts energy in the form of IR – that's how the earth's surface is almost exclusively warmed. But it doesn't all stay as IR energy for long – it is converted to other forms of heat/energy. Air currents and ocean warming are the obvious ones. Which warm things up which in turn emit their own IR.

You could be sitting in a dark room at night with no visible light at all and still be surrounded by IR.

So what – exactly – is the point you're trying to make?