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lighting

No Dan you didn't miss it, I mentioned in the comments on your post below that like your source theirs didn't specifically mention cannabis either which is why I'm trying to find a source that specifically mentions the DLI saturation point of cannabis, the closest thing I can find is HT's claim of 25 mol per sq m
 
I think there must be some sort of confusion.

Yes, I know DLI can be calculated from PPFD, it's actually pretty simple to do.

That still doesn't help me with the answers I'm looking for which is: What is the DLI saturation point of cannabis?

How does one know the plant has absorbed as much light as it possibly can within its photoperiod?
The light intensity might be low enough that the plant doesn't get light burn, but over the course of the lights on period it may receive more light than it can process, therefore wasting light and power.

I wasn't interested in this topic until I saw Tyler claim 100-200 moles per day is good which I thought to be outrageous since intense sunlight doesn't really go above a 60 DLI but there seems to be no evidence (that I can find anyway) to either confirm or disprove his claim.
Just got me to thinking, I run my autos on 24/0 which lots of people seem to agree with autos more light is better but then there's those that think that after about 20 hours of light per day you get little to no return for that extra 4 hours of light which to me says plants are approaching, possibly even passing their DLI saturation point.

Anyway, this is going well above and beyond the original topic of this thread so I'll leave it at that for now and continue to search for the answers I am looking for. I appreciate your time and the intellectual conversation, none of my mates would have even the slightest clue about these sort of things. If I come across some conclusive evidence I will be sure to let you know. Knowledge is power.
 
No theres no confusion, i know exactly what you mean. But it runs under the assumption that cannabis has a daily limit and then just suddenly stop or slow down, as if they have a counter.
Most green plants are classified as either C3 or C4 which represents how carbon(C) is used during photosynthesis. Cannabis is a C3 type, meaning that it doesnt store carbon at night and use it during the day. Carbon is sourced exclusively from the air and so it does not depreciate at the end of the day like C4 type trees do. This is why carbon supplementing works with cannabis, which would not if it were a C4 type.
In order for photosynthesis to slow down, there needs to be a limiting factor in the photocenter to prevent the ongoing process.
I will be going over my books on this heavily tonight, if you wish to discuss or talk further about this let me know. You have peaked my interest.
Regarding longer photoperiods, yes i believe it is beneficial. I think this contradicts a statement i made on a forum a while back with someone asking the same question. But my understanding has changed.
 
OzBud I know this is old but i had obviously missed this reply. The HT reference is completely inaccurate with what they are claiming. They completely misunderstand the article they reference to. The article describes the Daily Light requirements for plants, not the saturation. You will find no article referencing about a maximum level of DLI a plant can tolerate. DLI was and is intended for the measurement of light over time to determine a plants daily photosynthetic quota in outdoors or greenhouse environments. Using this information they can determine whether or not it is required to provide supplemental lighting. ;)
 
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