HalfArsedFarmer
Well-known member
Why the inverse triangle may be wrong.
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LED and BUD QUALITY
- Thread starter Tropical Sun
- Start date
Why the inverse triangle may be wrong.
IMO you want both.
Look at some PPFD maps; the closer the fixture is, the higher the average PPFD, but the less uniform the spread is - too high in the middle, too low at the edges etc.
If you’re using a tent & one light you can probably afford to spend the extra $ on the running costs of a higher output light and hang it higher. Same PPFD at canopy, but more evenly distributed.
It will really come down to what your personal priorities and preferences are.
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Nobody is hanging lights that high. People still running DE Hps at scale are typically around 5-6 ft above the canopy depending on several variables. With new ballasts, new hoods and bulbs an average ppfd of 9-1000+ is achievable with favorable spacing, which their footprint is not square, more rectangular. Also, perimeter lights should be closer to walls than you might expect, its about light reflection and cross lighting. If you get too close you actually lose light because you arent getting as much angular crossover lighting. Theres a sweet spot and its very different than one hood in a tent.
goingrey
Well-known member
Wow the mylar tent really improves the efficiency. From -50% to -12%.
HalfArsedFarmer
Well-known member
This type of thread is why some times ic mag is the shit.
With that thought or theory
I’ve seen stress from either heat or light intensity burn tops/ tips of colas / Nutrient deficiency
This seems like a overall reaction
While some don’t seem to suffer as much and each strain and room has different specifications
From example my humidity & Heat was higher than I’d like at certain times during the grow . This plus I believe light intensity and height restriction
Have made some phenos show elongated tips / extreme foxtail
While I’m sure OHaze genetics carry this trait it is amplified in certain conditions
Also in regards to light intensity n flowers directly under the light
OHaze seems to like not such intense lighting. The bottom half of the colas are fattening quicker as well as maturing quicker another thing commonly seen with Original Haze
1luvbigherb
HalfArsedFarmer
Well-known member
Hi BH
How many times have you seen a nutrient deficiency due to lamp distance?
Thats not something I've ever thought about. 20 plus years!!
Normally as you say burnt tips and the likes but never deficiency as a case of stress without visible signs.
I'm actually seeing this in some autos ATM. All the inputs are the norm. I couldn't find the issue.
I may turn the power down and see if they pick up.
Thanks!
How many times have you seen a nutrient deficiency due to lamp distance?
Thats not something I've ever thought about. 20 plus years!!
Normally as you say burnt tips and the likes but never deficiency as a case of stress without visible signs.
I'm actually seeing this in some autos ATM. All the inputs are the norm. I couldn't find the issue.
I may turn the power down and see if they pick up.
Thanks!
Hiddenjems
Well-known member
Some of the thought that goes into these setups is that the gain in vertical space (taller plants) gives more cubic feet of canopy than with closer lighting.
I think now there are higher producing methods, but prefer the bud quality from bigger plants.
greyfader
Well-known member
one thing to consider is that taller plants that are top-lit have the cannabinoids stratified in potency from the top down. They are stratified by distance from the lights
this is the same paper i've linked to before;
"Cannabinoid content in organs found at various heights along the cannabis plant were analyzed (Fig. 1a and b). Significant variation was observed among differing heights for almost every cannabinoid studied. For most cannabinoids, the content increased with plant height and was greatest at the top of the plant. This was observed for THC, CBD, cannabigerol (CBG), cannabichromene (CBC), and tetrahydrocannabivarin (THCV). In this study we report location-specific and organ-specific effects on chemical profiles of cannabinoids and the ionome in the medical cannabis (Cannabis sativa) plant. A number of important morphological-related chemical trends are presented. The cannabinoid profile changes with location along the plant demonstrating significant variation among differing heights for almost every cannabinoid studied. The spatial gradient of cannabinoids in the cannabis plant demonstrates organ and location-specific regulation of secondary metabolite accumulation."
so, growing upright plants without side or intracanopy lighting degrades the overall cannabinoid content with dilution by mass. you may get a larger plant but it will have less total cannabinoids per volume.
for the greatest uniformity and overall potency, a sea of green or screen of green will get the best results with top lighting alone because you are presenting a flatter plane of canopy to the lights.
the pics show the work plane at about 30" using sunlight supply acde fixtures focused tightly on the plants. this produced about 1200 umols ppfd.
Attachments
But did they measure viroid level? As studies into viroid looking at distribution found some plants with almost none at the tips, and THC of high 20's and on lower buds closer to the roots, a lower THC of in the teens %, and lowered terpene levels too..I see the two studies correlating, but the one measuring light not also measuring viroid level, so getting skewed data. If they measured in a greenhouse with bright summer sun and diffusing plastic, where the light drop off due to inverse square law is almost nothing, as the light source is the sun, so far away, that a meter or two difference in distance from the source, and the diffusion means for all purposes the light at top and bottom of canopy is just influenced by shade and nothing else, if one picks samples from exposed to light, sites at top and bottom, one would see the same results, in an infected crop, and then not in a clean uninfected crop. So if one is missing that critical factor in your study, it is easy to jump to conclusions, until one has looked at more data in more situations, and seen that there is another anomaly one is not taking into account. Once you work that out and take it into account, it explains a lot of the wierd shit us older growers have been encountering for decades.
You telling me the THC is lower on that lower bud, than the cola? Its not..but this plant although infected, has a load on the bottom end of the scale and only in the next, or the next, generation of clones from the mother would you see the slow downhill slide begin.. it indoor situation with light from one plane close by, with similar plant one gets similar results though. But with infected plants, even in greenhouse light with high light top to bottom on outside of tables, the lowers are way less grade than tops, if measuring THC a whole drop. In indoors with quite a more severe light gradient to the bottom of canopies, it is almost like that lower growth that is close to the roots, looses the fight with viroid worse and duds more..so yes its related to light..but through the filter of viroid, with clean plants, how much it affects is FAR less and in greenhouse environments with different light behavior it doesn't affect quality of bud..but if infected does dramatically due to proximity of lowers to roots and high load in roots moving up with sugars in flower. In high light enviroments, with fresh CO2 available the plant will just grow more, fatter faster, but with viroid all sorts of weird shit happens...throw viroid into the equation and high light can act like an abiotic stress factor..with LEDS often one doesnt have the nice warm temps that HPS provided, and metabolic rate drops and the plants growth outpaces viroid less and one can see all sorts of weird shit attributed to all sorts of things..but often its viroid..sometimes not..but for most, this is an extra filter we gotta realize we seeing stuff through. It affects more of us than we realize.
You telling me the THC is lower on that lower bud, than the cola? Its not..but this plant although infected, has a load on the bottom end of the scale and only in the next, or the next, generation of clones from the mother would you see the slow downhill slide begin.. it indoor situation with light from one plane close by, with similar plant one gets similar results though. But with infected plants, even in greenhouse light with high light top to bottom on outside of tables, the lowers are way less grade than tops, if measuring THC a whole drop. In indoors with quite a more severe light gradient to the bottom of canopies, it is almost like that lower growth that is close to the roots, looses the fight with viroid worse and duds more..so yes its related to light..but through the filter of viroid, with clean plants, how much it affects is FAR less and in greenhouse environments with different light behavior it doesn't affect quality of bud..but if infected does dramatically due to proximity of lowers to roots and high load in roots moving up with sugars in flower. In high light enviroments, with fresh CO2 available the plant will just grow more, fatter faster, but with viroid all sorts of weird shit happens...throw viroid into the equation and high light can act like an abiotic stress factor..with LEDS often one doesnt have the nice warm temps that HPS provided, and metabolic rate drops and the plants growth outpaces viroid less and one can see all sorts of weird shit attributed to all sorts of things..but often its viroid..sometimes not..but for most, this is an extra filter we gotta realize we seeing stuff through. It affects more of us than we realize.
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Frankenbeanie
Member
Every photo you see online. People blaming heat/light for their taco/burn have not grown in desert.
Exactly, you can see weed growing in Afghanistan, in crappy sandy dirt, PH9 calcium carbonate based dirt...watered once or thrice a season, in the baking sun, in hot temperatures, and the weed looks very happy. Out here my best weed comes from mid summer greenhouse crops where I cannot get the temps under 35 degrees in midday, and the PPFD is 1600plus diffused no drop off lighting from the sun inside and even in the garden in the 3000ppfd midday summer sun, the plants look like a pig in shit. People blame a lot, on a lot. But weed is quite adaptable if you get its basics right. Plant above on a taco mission, but its super happy, that is just genetic. Sometimes viroid makes em do that, for this plant it looses its taco when the viroid level climbs...Who knows...hahaha
greyfader
Well-known member
what you are saying about the viroid makes a lot of sense. but this particular paper was done in Israel in 2018 before the hop latent viroid became prevalent in cannabis crops. so they may have had the viroid and maybe not.
but, please explain this statement from you,
"You telling me the THC is lower on that lower bud, than the cola? Its not..".
talking exclusively about indoor plants being grown upright with top lighting only do you mean that the lower flowers further from the light will have the same % thc as the apical flowers?
please clarify!
From my experience now, if not infected the THC between top and bottom buds will be very close, if infected on low load, you will see differences as the viroid collects at different rates at diifferent parts of the plants as it moves up from the roots where it has collected. It is getting produced everywhere, and moving down, and building in root zone, then moving up when flowering triggered, or its appears so on the studies...watch the youtube vids by medical genomics, recent ones..they explain a lot with their studies on infected stuff.
Even in plants that I've got flowering now, in greenhouse, in almost no load but still infected plants, the difference between lower buds frost and tops is not noticeable but in same clones coming from older moms, the difference is quite noticeable. Though light less of a factor there...than indoor.
greyfader
Well-known member
" medical genomics", yes, i've seen quite a bit of information about the viroid and other subjects from Medicinal Genomics. i've done business with them before when i was the director of a 10k Sq ft cbd facility in Nashville Tn.
"From my experience now, if not infected the THC between top and bottom buds will be very close"
but focusing on your statement above, how did you quantify the difference between top and bottom buds?
did you use lab tests to arrive at this conclusion?
as a long time smoker, if u ask me where i want my bud from , its the tops.... not scientific but just my observation after smokin for 50 yrs
greyfader
Well-known member
yeah, i've always thought so. it's just another one of those things that old growers understand almost intuitively. but it's nice to see research that backs that up.
this is the paper we are talking about;
GF-Z
Active member
Recent studies revealed shocking coleration between crystal meth induced brain damage and LED light efficiency used in horticultural applications.
It seems person mental state can have major effect on LED lights they are using. Here is published graph. This is one step futher understanding quantum connections between our reallity.
It seems person mental state can have major effect on LED lights they are using. Here is published graph. This is one step futher understanding quantum connections between our reallity.
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exoticrobotic
Well-known member
