I always thought the plants were praying for more light
I thought it was because the plant is metabolizing faster than The amount of light it’s receiving, so it prays up trying to capture more light
I think that is agreat subject! I always took it as a sign nutrient and watering are on point; and they might need more light
I always thought the plants were praying for more light
I thought it was because the plant is metabolizing faster than The amount of light it’s receiving, so it prays up trying to capture more light
I think that is agreat subject! I always took it as a sign nutrient and watering are on point; and they might need more light
There is another well known member who is a solid grower that feels the way you do.
He feels it is a sign to bring the light slightly closer and the leaves will level out.
Might be true, might be beneficial IDK, I prefer keeping the light in the same place and maintain the praying.
There are plenty of edu type links that explain why many plants raise their leaves outside but I've never found any explaining what is going on when a cannabis plant prays indoors.
just as i was in the kitchen.
the above plants in their evening.
simply a lil circadian cycle leaf drop, not their i am oversaturated, leave me alone drop.
which i can create with strong led light.
theyre still transpiring, but allready less then over day.
Praying intrigues me, but I think its just simple plant happiness
3 examples (I can sort pics if needed). I've got Strawberries praying outside, also had it with cuts in the prop last year and with plants in my 4 x 8. These are all in different environments at different states of growth / flowering yet all showing the same praying
4 x 8
Picture was take after watering..with just water (in soil)
I don't think its nutes (see pic above), its not roots as my cuttings in the prop had none when they prayed and we've a mini heat wave here in the UK so there's enough light / heat for the Strawberries outside.
Only conclusion I can come to is the plant is in the sweet-spot and just happy with every equation (heat, light, humidity etc..)
To me these look happy and thriving! I’d say that if somebody thinks that that is what plants look like when they’re not growing well, I can’t imagine what their plants look like. I’ve been growing for about 30 years, and this is what I shoot for, if it’s wrong I don’t want to be right!
Well ,to be honest,I was not able to spot any of “praying “ leaves at the above photo.Seems like there’s a misunderstanding as to what exactly is
praying leaves.
At light-saturated plants,leaves are quite erected.Usually ,their tips are pointed upwards and opposing leaves look like closed hand palms,thus the
“praying” adjective.
i dont discount it, like, maybe UV adds a lil something, maybe it doesnt. Seen a lot of led weed beat out hps, seen it go the other way a lot too, the better grower wins nearly every time. Its a multi billion dollar industry and i reckon the men in white coats are probably on top already. I think if there were any major advantages to be had by tuning spectrum we'd already know. I want to be wrong but i dunnooooo, im not very scientific either sooooo...no point listening to me lol
You can already control stretch to a degree with blues imo.
I'm pretty well convinced that UV - properly applied - can increase cannabinoids and terpenes, but I'm not yet convinced that most growers adding UV are actually seeing notable real-world improvements (hence, placebo). So many factors involved. I'm also not yet convinced that chasing UV enhancement is even worthwhile right now. I've read that you can see up to a 30% increase in THC with the addition of UV. Okay, maybe, if all the stars align, but I think most would be lucky to see half that, at a 15% boost. I just can't be bothered. If the bud produced under straight 3000k wasn't already potent, frosty goodness, then yeah, I'd be chasing too, but... Naw. I'll wait for a cheaper, more practical, LED-based UV solution. Maybe by the time we have that we'll be better able to accurately predict the outcome. And maybe not. Personally, I think genetics are by FAR the biggest factor, and there's enough variability there to keep us guessing for many years to come.
I'm pretty well convinced that UV - properly applied - can increase cannabinoids and terpenes, but I'm not yet convinced that most growers adding UV are actually seeing notable real-world improvements (hence, placebo). So many factors involved. I'm also not yet convinced that chasing UV enhancement is even worthwhile right now. I've read that you can see up to a 30% increase in THC with the addition of UV. Okay, maybe, if all the stars align, but I think most would be lucky to see half that, at a 15% boost. I just can't be bothered. If the bud produced under straight 3000k wasn't already potent, frosty goodness, then yeah, I'd be chasing too, but... Naw. I'll wait for a cheaper, more practical, LED-based UV solution. Maybe by the time we have that we'll be better able to accurately predict the outcome. And maybe not. Personally, I think genetics are by FAR the biggest factor, and there's enough variability there to keep us guessing for many years to come.
Well ,to be honest,I was not able to spot any of “praying “ leaves at the above photo.Seems like there’s a misunderstanding as to what exactly is
praying leaves.
I have had a # of grows where my leaves would be healthy and flat then go into a praying mode (In Soil). Often near the switch to flower which is why I feel root development played a role. Might be confirmation bias, I have also had mj clones that prayed when sitting in stagnant water with brown roots so IDK, again just speculating. Reading about turgidity in plants might help understand what's going on.
One time it happened after adding gypsum, Epsom salt or dolomite lime near flip. Wish I kept a record of it. Might have been more than one item added IDK.
Who knows why. May have been the additional calcium. I never recall it happening when adding magnesium but I feel it has happened when adding calcium.
I think lukio mentioned it happening when lowering e/c?
Anyone else have experience with an over night change or quick change to praying even if you can't explain why?
I lost count of how many times it has happened to me over the last 25 years.
hope you don't mind if I add a bit to the discussion.
This is one topic I've thought so much in the past and is one of the prime reason why I keep reading books about plant physiology because it's about the outer appearance of a plants happiness.
(the other is flowering induction but that's mostly genetic shit)
"OPEN AND SHUT: To test whether speed of stomata opening and closing can increase productivity and water use efficiency, researchers added the synthetic light-activated BLINK1 ion channel to guard cells in Arabidopsis (1). The BLINK1 channel allowed potassium ions to move into a cell within two minutes of activation by blue light (2). The increase in ions inside the cell caused the guard cells to take on water and swell in size, opening the stomata to allow entry of carbon dioxide (3). Within 8 to 10 minutes of being in darkness, the BLINK1 channel’s activity decreased and the guard cells began to shrink, closing the stomata and preventing water from leaving the cell (4). See full infographic: WEB | PDF"
actually its not only blue light but also UVB (even stronger):
Abstract. The ultraviolet action spectrum for stomatal opening was measured using epidermal peels from leaves of broad bean (Vicia faba). The spectrum was calcu
One of these articles cleared out why our veg gone so shite, plants pussying out on low light levels even though everything was hot and humid enough, shitty and hanging and bleachy looking. Thing was the gas heater, the high amount of co2 got the stomata closed and no drinking, no nutes no posture.
Is stomata closure/ opening really tied to the amount of CO2 in the ambient air? I think not. It's *mostly* related to the ambient rH - which needs to be right, not too low (because then a plant would loose too much water, so they close them self-limiting the CO2 intake) but if it's too high, then the air cannot take more water and transpiration is also hindered (by physics this time). With extreme high rH this can even result in a fake-guttation (I say fake because real guttation needs special cells ("Hydathoden" in german) that mostly water-based plants (halophytes) have.
There are even some breeders out there that claim this is Cannabinoids, but it's just BS - may as well pour a cup of sugarwater over ones buds and label it "BHO bud strain"
sounds like a marketing gag to me... "spray with lights on" "leaf burning" "full NPK formulae" "add <whatever> oil" <-- lots of wrong infos & some is even detrimental to transpiration.
Do you perhaps know the active ingredient in their product (the one responsible for the stomata opening)? Because the listed substances are just the normal leaf application minerals (bar P - heavily doubt a plant can utilize this as it needs special transport molecules and these sit in the roots - but ofc MKP is cheap to buy... )
I was under the impression that “praying “ leaves are a sign of photo saturation ( light stress ) .
Leaves erect in such way ,
in order to decrease their available surface to incident light ,for protecting
the stressed light harvesting systems.
In intercropping systems shading conditions significantly impair the seed yield and quality of soybean, and rarely someone investigated the minimum amount of...
Leaf angle and leaf absorptance are two leaf parameters that link a leaf and its physical environment. These characters affect both the amount of solar radiation incident on a leaf and the fraction of that incident light which is actually absorbed. Differences in...
In intercropping systems shading conditions significantly impair the seed yield and quality of soybean, and rarely someone investigated the minimum amount of...
I think you are confusing heat stress with transpiration - the former results in a bilateral closure (=relative surface reduction) of the leaf area (as seen as V from the side) - which is always going to happen if the plant cannot do away with too much intra-leaf heat - regardless of "praying".
But drooping can have many reasons.
true, but there's a common misconception about it, when people think a plant is "full" in sugar & starches so it doesn't want to do PS anymore... what, in fact, the plant doesn't want to a accumulate anymore is a toxic by-product of PS (when PS has to be done with O2 instead of CO2) and this is mostly cleared during the night-phase.
i would second that, many factors.
one factor is for sure also how much oxygen is in your root zone.
for me its easier to keep the plant praying in a hydro system then in soil.
adding some h2o2 have a effect too due to the oxygen released, i guess many observed this phenomen here allready.
this effect of course goes hand in hand with a healthy root system.
O2 is very useful to prevent some evils in your pot, and if roots are happy, so is the plant. But it doesn't have to be O2 for the roots to be happy - any kind of atmosphere would work - because the roots need to be able to do a "gas exchange", which, in this case means that the roots want to release stuff.
The issue with green light is that it exerts an antagonistic effect on other blue light-induced responses, including stomatal closure (Frechilla et al., 2000) (...)
that paragraph for "green-light" would therefore implicate that both the sun and CMH lamps should decrease both growth & cannabinoid content because of the huge presence of green light.
Starting as an outdoor grower I cannot observe this - outdoor weed is of the highest quality plus plants (esp. big ones) can be much more healthy.
Also CMH is known for its frosty buds.
There is a common problem with citing individual studies, it may "mislead" due to the isolated experiments under which these studies are drawn.
Only academics which have this as their chosen field are actually able to value the results of studies and "place them at the right place into the big picture".
That's why it's actually much better to simply learn from what the Profs have put together as "standard models or teachings" because they can draw conclusions much better than any of us can... esp. since they don't smoke weed
there is some merrit to what you are suggesting although the term "metabolizing faster" is too unprecise in this regard, because "metabolism" encaptures many aspects of plant physiology. Guess most of us have observed drooping top leaves at the EOD and praying in the mourning. Plants can "anticipate" (via the Circadian clock) when the mourning comes and already prepare themselves - if you open your tent half an hour before lights-on happy plants will already pray.
In this case the "praying" even costs them energy - although other factors (like the transpirational pull) does not. The latter is strictly physical whereas the former is induced by the intra-cellular turgor pressure by release/uptake of ionic potassium induced by hormones (simplified)
There is another well known member who is a solid grower that feels the way you do.
He feels it is a sign to bring the light slightly closer and the leaves will level out.
Have observed this too, it looks as if the lights exerts a certain "thrust" to the leaves.
This is something that may cast a shadow of doubt on some of what I've just said e.g. if PS-induced transpirational pull is responsible for this "praying" then it should actually even pray more when lights are closer...? But the whole subject consists of multiple reasons so a plant may
- stretch stalks up in search of exposure to direct light (plants always "think" of "go up" or "higher" as shade avoidance and this is true to some extent also for stalks
- release this stretch when exposed to full light so that the top leaves gain more hard light
- typically bottom leaves aren't streched up like top leaves although they receive much less lights indoors (outdoor plants don't show that extreme...)
- moving lights closer may result in a higher intraleaf- and leafsurface temperature - this may NEGATIVELY impact VPD resulting in a loss of stomatal gas exchange = drooping (your solution to let the lamp where it is spot on - plants love K.I.S.S. and not fiddling around with their environmental variables!
If the electrolyte charge outside the rhizosphere/ plasmalemma is low compared to the plants internal EC then the internal plant "salts" are going to attract strongly water (through osmosis) which add to roots internal osmotic pressure (but this is only a very small increment of the internal cause of fluid movement, normally like ~2-3% - although there are special situations where this could change - e.g. at the topping wound sometimes xylemic fluid bloods out - although there are no superordinated leaves remaining (which would cause a transpirational pull....)
And this is how the osmotic root pressure actually can be quantitatively measured:
and also the reason why seedlings need a less high EC (plain water) as their Cotyledons contain a high amount of salts which is a seedlings method to draw water to it (albeit having almost no root system).
People that feed seedlings actually torpedo that mechanism.
It's exactly like Rocket Soul explained here on overfeeding - as that mechanism works both ways:
however, one should note that these interactions (Transpirational Pull & Osmotic Pressure) act on different parts of the plant (which are separated) so it's not that the transpirational pull substracts from the rootpressure (or vice versa) - otherwise there wouldn't be a rootpressure because the transpirational pull is actually much stronger.
Both plants look rather light-depraved to me - observe the weak side branches & low-finger count?
The long internodes may be from the stretch of a young plant... how is it that it is already in flower that small? Perhaps it couldn't grew because it lacked light.... plus, the bottom leaves are erratic because they were shaded (mostly left side) - that's why the top stretches high - the plant "feels" the stronger light above.
In nature the difference of direct sunlight or just shaded light is 115k lux vs ~~25k lux. Cannabis is one of most light hungry (and effective) C3 plant that there is.
The effects of praying due to osmotic pressure can be best shown on young plants because they don't have that many leaves & less distance between roots & leaves:
This is a seedling unfertilized in a void substrate - fed with RO.
Notice the deficient cotyledons? It hardly grew, but had to drink in order to cool via transpiration.
Under 7200k CFLs (arond 115w @ 15cm distance)
(run through google translate, this version is much more complete than the english one)
What also adds:
- cellular "lengthgrowth":
[the image to the right illustrates when a plant *grows* it will also result in an increased internal pressure (so if something is not right with the nutrient mix, and growth is throttled down ("law of capping minimum") the leaves may also droop); as well as the text explains how wilting from drought stress functions. Plants regulate alot of their fluidic internal cellular pressure with Potassium - if this "axxis" K-Ca-Mg is out of whack a lot of regulatory functions are lost, as well.]
Sadly most of my college-grade literature is in my motherlanguage (plus it seems like that the german wikipedia is more complete & extensive when it comes to plant physiology) so I don't know what else I could cite/show you, but perhaps these are already enough keywords so one could go on a search by yourself if you find this topic interesting.
Also tagging @Dr. Who whom I found to be the most competent interlocutor when it comes to Cannabis & plants (I hope he does well after his surgery...)
BTW nice thread @lukio - keep it up (and the leaves, too)
(run through google translate, this version is much more complete than the english one)
What also adds:
- cellular "lengthgrowth": View attachment 4596202
[the image to the right illustrates when a plant *grows* it will also result in an increased internal pressure (so if something is not right with the nutrient mix, and growth is throttled down ("law of capping minimum") the leaves may also droop); as well as the text explains how wilting from drought stress functions. Plants regulate alot of their fluidic internal cellular pressure with Potassium - if this "axxis" K-Ca-Mg is out of whack a lot of regulatory functions are lost, as well.]
Sadly most of my college-grade literature is in my motherlanguage (plus it seems like that the german wikipedia is more complete & extensive when it comes to plant physiology) so I don't know what else I could cite/show you, but perhaps these are already enough keywords so one could go on a search by yourself if you find this topic interesting.
Also tagging @Dr. Who whom I found to be the most competent interlocutor when it comes to Cannabis & plants (I hope he does well after his surgery...)
I look forward to reading the posts above.
Going to take some time.
What's up with the Doc???
I've been spending most of my time the last few months in the covid 19 thread in TNT and haven't heard anything.
He was last seen and posted on May 25th!
Any updates?
I look forward to reading the posts above.
Going to take some time.
What's up with the Doc???
I've been spending most of my time the last few months in the covid 19 thread in TNT and haven't heard anything.
He was last seen and posted on May 25th!
Any updates?
Just did some surfing and read the thread showing he made the move to try LED last month. Didn't think that was going to happen for a while. Richard made the move, Doc made the move, what is the world coming too!
Hope he is OK. His last post is on his LED thread saying he was planning to update that night.
20 minutes away from having a shot and a beer. The toast tonight will be to his health, hope he is doing well.
Just did some surfing and read the thread showing he made the move to try LED last month. Didn't think that was going to happen for a while. Richard made the move, Doc made the move, what is the world coming too!
Hope he is OK. His last post is on his LED thread saying he was planning to update that night.
20 minutes away from having a shot and a beer. The toast tonight will be to his health, hope he is doing well.
oh yeah the SBS ... he wouldnt forget about it, wouldnt he?
actually Doc combined both LED + HPS in a room... temp wise its optimal... the HPS are also filling the room with FR IR which the LEDs lack... HID + LED is cool, add a UVB Cfl to complete the lamp-zoo XD
hope you don't mind if I add a bit to the discussion.
This is one topic I've thought so much in the past and is one of the prime reason why I keep reading books about plant physiology because it's about the outer appearance of a plants happiness.
(the other is flowering induction but that's mostly genetic shit)
he is actually right, as are you - its multi-causal...
here's a first hint, from your link
"OPEN AND SHUT: To test whether speed of stomata opening and closing can increase productivity and water use efficiency, researchers added the synthetic light-activated BLINK1 ion channel to guard cells in Arabidopsis (1). The BLINK1 channel allowed potassium ions to move into a cell within two minutes of activation by blue light (2). The increase in ions inside the cell caused the guard cells to take on water and swell in size, opening the stomata to allow entry of carbon dioxide (3). Within 8 to 10 minutes of being in darkness, the BLINK1 channel’s activity decreased and the guard cells began to shrink, closing the stomata and preventing water from leaving the cell (4). See full infographic: WEB | PDF"
actually its not only blue light but also UVB (even stronger):
Abstract. The ultraviolet action spectrum for stomatal opening was measured using epidermal peels from leaves of broad bean (Vicia faba). The spectrum was calcu
www.plantphysiol.org
(observe Figure 4. the peak @ 290nm)
BTW thx to copshopgrow for this link!
Is stomata closure/ opening really tied to the amount of CO2 in the ambient air? I think not. It's *mostly* related to the ambient rH - which needs to be right, not too low (because then a plant would loose too much water, so they close them self-limiting the CO2 intake) but if it's too high, then the air cannot take more water and transpiration is also hindered (by physics this time). With extreme high rH this can even result in a fake-guttation (I say fake because real guttation needs special cells ("Hydathoden" in german) that mostly water-based plants (halophytes) have.
There are even some breeders out there that claim this is Cannabinoids, but it's just BS - may as well pour a cup of sugarwater over ones buds and label it "BHO bud strain"
sounds like a marketing gag to me... "spray with lights on" "leaf burning" "full NPK formulae" "add <whatever> oil" <-- lots of wrong infos & some is even detrimental to transpiration.
Do you perhaps know the active ingredient in their product (the one responsible for the stomata opening)? Because the listed substances are just the normal leaf application minerals (bar P - heavily doubt a plant can utilize this as it needs special transport molecules and these sit in the roots - but ofc MKP is cheap to buy... )
I think you are confusing heat stress with transpiration - the former results in a bilateral closure (=relative surface reduction) of the leaf area (as seen as V from the side) - which is always going to happen if the plant cannot do away with too much intra-leaf heat - regardless of "praying".
But drooping can have many reasons.
true, but there's a common misconception about it, when people think a plant is "full" in sugar & starches so it doesn't want to do PS anymore... what, in fact, the plant doesn't want to a accumulate anymore is a toxic by-product of PS (when PS has to be done with O2 instead of CO2) and this is mostly cleared during the night-phase.
O2 is very useful to prevent some evils in your pot, and if roots are happy, so is the plant. But it doesn't have to be O2 for the roots to be happy - any kind of atmosphere would work - because the roots need to be able to do a "gas exchange", which, in this case means that the roots want to release stuff.
that paragraph for "green-light" would therefore implicate that both the sun and CMH lamps should decrease both growth & cannabinoid content because of the huge presence of green light.
Starting as an outdoor grower I cannot observe this - outdoor weed is of the highest quality plus plants (esp. big ones) can be much more healthy.
Also CMH is known for its frosty buds.
There is a common problem with citing individual studies, it may "mislead" due to the isolated experiments under which these studies are drawn.
Only academics which have this as their chosen field are actually able to value the results of studies and "place them at the right place into the big picture".
That's why it's actually much better to simply learn from what the Profs have put together as "standard models or teachings" because they can draw conclusions much better than any of us can... esp. since they don't smoke weed
there is some merrit to what you are suggesting although the term "metabolizing faster" is too unprecise in this regard, because "metabolism" encaptures many aspects of plant physiology. Guess most of us have observed drooping top leaves at the EOD and praying in the mourning. Plants can "anticipate" (via the Circadian clock) when the mourning comes and already prepare themselves - if you open your tent half an hour before lights-on happy plants will already pray. View attachment 4596184
In this case the "praying" even costs them energy - although other factors (like the transpirational pull) does not. The latter is strictly physical whereas the former is induced by the intra-cellular turgor pressure by release/uptake of ionic potassium induced by hormones (simplified)
Have observed this too, it looks as if the lights exerts a certain "thrust" to the leaves.
This is something that may cast a shadow of doubt on some of what I've just said e.g. if PS-induced transpirational pull is responsible for this "praying" then it should actually even pray more when lights are closer...? But the whole subject consists of multiple reasons so a plant may
- stretch stalks up in search of exposure to direct light (plants always "think" of "go up" or "higher" as shade avoidance and this is true to some extent also for stalks
- release this stretch when exposed to full light so that the top leaves gain more hard light
- typically bottom leaves aren't streched up like top leaves although they receive much less lights indoors (outdoor plants don't show that extreme...)
- moving lights closer may result in a higher intraleaf- and leafsurface temperature - this may NEGATIVELY impact VPD resulting in a loss of stomatal gas exchange = drooping (your solution to let the lamp where it is spot on - plants love K.I.S.S. and not fiddling around with their environmental variables!
Some notes: stomata aperture is indeed also stimulated by uvb, along with uva 360 and around 420-430: they seem to call it a 3 finger action spectrum: this is one of the reasons i like the highlight boards, extra boost from 400-430 nm.
Co2: it does indeed affect the stomata closing it, or rather: it increases tthe threshold of blue light induced opening. There is an article somewhere, im not sure if ive quoted it here on riu or in the other place, if you give me some time i might be able to track it down, but it shouldnt be hard by googling stomata aperture spectrum. Thinknof it this way: the stomata "breathes" co2, higher concentration more breathing.
The uv article you quoted was my first wetting of the toes in this subject, iican honestly not remember if i passed it to Cobs or if it was the other way around. I recommend anyone reading it.
)
