Lighting What's the best lighting cycle for autos - 24/0, 20/4 or 18/6

[Tony21]

That's what I and many others are trying to figure out. What I'm hoping to see is conformation of Big Sm0's less is more theory lol! His grows fly in the face of the old concept of more light is good, and too mush is just enough! I think maybe a good way to sum up DLI simply is, there is a maximum amount of photons a plant can process, which also indicated there is a maximum constant level and we all may be using more light than we need.
I've also recently read that plants under artificial light still respond as though sun just rose, taking up to 15 minutes to become fully active. Maybe those controllers that create a "sunrise-sunset" may not be so silly after all!

Yes, maybe, so how to fit auto's into that, does ruderalis actually have diurnal detectors?

 

[Tony21]

I was talking to one of the Amare guys (Anthony, not Vic) and he was saying that genetics also play in the role of how much a plant can uptake for light, citing that certain strains have a much larger threshold than others for DLI. Maybe just like nutrients, some plants uptake different than others, some phenos feed different than others, etc.

Sadly , I think you may be right so the breeders should be asked,not only the light makers.
why they don't give this information as surely they know and use DLI in their breeding...... Coughing discretely..... :smoking:

 

[Son of Hobbes]

Yes, maybe, so how to fit auto's into that, does ruderalis actually have diurnal detectors?

Also begs the question, how much we can use "ruderalis" as go-to for explanation of plant growth when the majority of available strains are hybrids of indica/sativa and ruderalis? I see people quote ruderalis facts on Facebook all the time, which is great, but.... how many people here are actually growing pure ruderalis? Not many, arguably.

 

[Tony21]

Also begs the question, how much we can use "ruderalis" as go-to for explanation of plant growth when the majority of available strains are hybrids of indica/sativa and ruderalis? I see people quote ruderalis facts on Facebook all the time, which is great, but.... how many people here are actually growing pure ruderalis? Not many, arguably.

Yes, doesn't make it any easier grrr

Here is some DLI figures

https://www.google.com/url?sa=t&sou...FjAFegQIBxAB&usg=AOvVaw1FnaZ6voo1p5n6qJTxKxx1

Needs download, don't know how to link or post a pdf link is that possible, I'm pretty computer stupid, is it possible?

 

[Tony21]

Another question is variations in DLI during grow cyclus and how quickly a plant can be refuelled, sale of argument, double the wattage/PAR and the lights ontime can be reduced by half or something like that??
Is there perhaps DLI curves and graphs out there somewhere!

A Breeder should state a DLI range in the strain description as a matter of course like genetic makeup and the other usual strain info. There's plenty breeders here, why not ask all of them for their strains DLI optimal requirements

I look forward to see the lightmakers explaining although I don't understand why they are needed to explain an established concept rather than a requirement, but heck, let's hear

 

[AMARE-TECH-Vic]

DLI

I was talking to one of the Amare guys (Anthony, not Vic) and he was saying that genetics also play in the role of how much a plant can uptake for light, citing that certain strains have a much larger threshold than others for DLI. Maybe just like nutrients, some plants uptake different than others, some phenos feed different than others, etc.

http://www.specmeters.com/assets/1/7/A051.pdf

Cannabis is a light intensive plant with a light saturation point of ~1500umol/m2/s with sativa up to ~1750umol/m2/s. Strains and even phenos can influence DLI requirement as stated. Sunlight under clear sky at peak hours is ~2000umol/m2/s with a DLI of ~55 - 60moles/day. Two fixtures of the same wattage can have different DLI numbers. The output/net ppfd is determined by the efficiency of the design, including reflectors, lenses, chip layout, etc.. For example our SE450uvb delivers 48.7 moles/pay, about the same as a summer day for optimum results. It has a profound impact on the growth characteristics, quality and yield of crops. DLI is important, but a complete 400-700 par spectrum is also needed for optimum results. Autos tend to require less intensity, possibly due to the longer photo-period.

 

[Son of Hobbes]

DLI



http://www.specmeters.com/assets/1/7/A051.pdf

Cannabis is a light intensive plant with a light saturation point of ~1500umol/m2/s with sativa up to ~1750umol/m2/s. Strains and even phenos can influence DLI requirement as stated. Sunlight under clear sky at peak hours is ~2000umol/m2/s with a DLI of ~55 - 60moles/day. Two fixtures of the same wattage can have different DLI numbers. The output/net ppfd is determined by the efficiency of the design, including reflectors, lenses, chip layout, etc.. For example our SE450uvb delivers 48.7 moles/pay, about the same as a summer day for optimum results. The DLI level has a profound impact on the growth characteristics, quality and yield of crops. DLI is important, but a complete 400-700 par spectrum is also needed for optimum results. Autos tend to require less intensity, possibly due to the longer photo-period.

Your ears must have been burning! Evening!

 

[pop22]

I'd like to see some links to data supporting your statements. Most charts I've sen say 1200-1500ppms, with CO2 supplementation. what I'm most curious about is the statement about autoflowers. It would seem to me that stabilized hybrid autoflowers have little Ruderalis left in them. I would think and have found no data one way or the other so its conjecture, that the DLI requirement for an autoflower strain would tend to follow that of the dominant strain. If you have information that would clear this up, it would be appreciated.

DLI



http://www.specmeters.com/assets/1/7/A051.pdf

Cannabis is a light intensive plant with a light saturation point of ~1500umol/m2/s with sativa up to ~1750umol/m2/s. Strains and even phenos can influence DLI requirement as stated. Sunlight under clear sky at peak hours is ~2000umol/m2/s with a DLI of ~55 - 60moles/day. Two fixtures of the same wattage can have different DLI numbers. The output/net ppfd is determined by the efficiency of the design, including reflectors, lenses, chip layout, etc.. For example our SE450uvb delivers 48.7 moles/pay, about the same as a summer day for optimum results. It has a profound impact on the growth characteristics, quality and yield of crops. DLI is important, but a complete 400-700 par spectrum is also needed for optimum results. Autos tend to require less intensity, possibly due to the longer photo-period.

 

[AMARE-TECH-Vic]

I'd like to see some links to data supporting your statements. Most charts I've sen say 1200-1500ppms, with CO2 supplementation. what I'm most curious about is the statement about autoflowers. It would seem to me that stabilized hybrid autoflowers have little Ruderalis left in them. I would think and have found no data one way or the other so its conjecture, that the DLI requirement for an autoflower strain would tend to follow that of the dominant strain. If you have information that would clear this up, it would be appreciated.

Plants are subjected to and withstand up to 2000umol/m2/s under natural sunlight (clear skies)outdoors with no negative effects. 2000umol is not needed for full growth nor feasible to produce with artificial lighting due to the power requirement. 1100-1400umol achieve the best results in our testing, depending on the strain and pheno.

We have not done any testing exclusively on autos. According to our growers feedbacks, it seems that autos tend to prefer less light intensity. More research and testing needs to be done on this subject.

https://loudbank.com/maximize-cannabis-growth-700-1500-or-2000-µmolm2s/

http://magazine.cannabisbusinesstimes.com/article/january-2017/the-key-to-maximum-yield.aspx

 

[Tony21]

Plants are subjected to and withstand up to 2000umol/m2/s under natural sunlight (clear skies)outdoors with no negative effects. 2000umol is not needed for full growth nor feasible to produce with artificial lighting due to the power requirement. 1100-1400umol achieve the best results in our testing, depending on the strain and pheno.

We have not done any testing exclusively on autos. According to our growers feedbacks, it seems that autos tend to prefer less light intensity. More research and testing needs to be done on this subject.

https://loudbank.com/maximize-cannabis-growth-700-1500-or-2000-µmolm2s/

http://magazine.cannabisbusinesstimes.com/article/january-2017/the-key-to-maximum-yield.aspx

Hey man, cool info, but who is this Richard Jones from Zenith LED Grow Lights you are linking to. Is he a led scientist?

To bring DLI back, doesn't the time it take to accumulate optimal DLI have a bearing on the light cycle depending on intensity and spectrum delivered?

I think the time it takes to accumulate DLI gives the light cycle, and so the specific light fixture and wattage used actually decides the light cycle...... Like an electric car, you don't wanna over- or undercharge, you want it to be charged just right....to my mind, flipping on the lights for 30 minutes daily at high intensity, DLI meter goes bing, bing, bing ....And everyone can be blissfully at rest until tomorrow

DLI requirements is what we need, not speculation about a catch all light cycle