Advanced light cycle

[Beta Test Team]

You still are assuming things you aren't proving, namely that your plants experience it, and therefore your lighting schedule prevents it.

I can make any claim I want, but it doesn't make it true. That same goes for you. The difference is I rely on data and studies to prove claims made, and you yourself said you don't trust studies funded by the government (which most are, through Uni. funds, grants, etc.).

If you don't first know if your plants experience it, you should not just assume they are, given the fact what causes it (abiotic issues) are not happening to your plants.

Also, you did not yet carry out any real studies on the effect of the your light schedule in your environment (by your own admission), so you can't say your plants are doing better, and even if they are, you can't say why...

Overall you're just making a few really big assumptions, and they are likely not correct.

 

[Riddleme]

You still are assuming things you aren't proving, namely that your plants experience it, and therefore your lighting schedule prevents it.

I can make any claim I want, but it doesn't make it true. That same goes for you. The difference is I rely on data and studies to prove claims made, and you yourself said you don't trust studies funded by the government (which most are, through Uni. funds, grants, etc.).

If you don't first know if your plants experience it, you should not just assume they are, given the fact what causes it (abiotic issues) are not happening to your plants.

Also, you did not yet carry out any real studies on the effect of the your light schedule in your environment (by your own admission), so you can't say your plants are doing better, and even if they are, you can't say why...

Overall you're just making a few really big assumptions, and they are likely not correct.

yeah growing the same clones in the same garden for over 2 years and then only changing one thing and then seeing an increase in bud size and bud density from that same clone in that same garden after that only one change and observing it is totally bogus

but what do I know?

 

[Beta Test Team]

It has been well known for a long time that visual observations that are not quantifiable are not reliable means to judge effects. And even if there is a difference that you can measure, and it's not insignificant, you can't say what is making the difference in terms of your claims, because you don't even know if your plants experience midday depression of photosynthesis.

What do you know, you asked? Just enough to make yourself unwilling to consider you're wrong and being smug while doing it, that's all. (I won't respond to you again.)

 

[Bubbleblower]

Midday depression of photosynthesis (either single or double) is not a forgone conclusion for indoor plants, nor outdoor plants.

You have a short memory:

In search of the ideal amount of PPFD and in relation to the Rubisco break it would be interesting to know if cannabis suffers from midday depression.

Yes, Cannabis does, just like other higher C3 plants. Which is often onset by high VPD and high PPFD (around noonish outside in the summer).

For once I actually agree it is not a forgone fact, because I have still never found any evidence of that. What I do know for sure though is rubisco breaks work, which I can only imagine must be related to midday depression.

(I won't respond to you again.)

Promises, promises.

 

[Beta Test Team]

Just because a plant can experience it doesn't mean the plant will experience it - why that is so hard for some people to understand I have no clue.

 

[Bubbleblower]

why that is so hard for some people to understand I have no clue.

Don't know, many people tried to make that clear.

 

[Only Ornamental]

I am currently playing with an odd schedule to see if I can see a change in midday depression. My current grow is a breeding seed run so I have no worries about yield and I am running my flower lights at 6.5 on, .5 off, 4 on, 13 off to see what I see?
...

First day of the new light cycle and already an observation has taken place. I have 2 in 1 gallon pots that have had to be watered every day for the past few weeks and when I went to water em today after their first 1/2 hour break they were fine, seems I can wait till tomorrow

for the last week if I missed it by more than 20 min they would be droopin

yeah growing the same clones in the same garden for over 2 years and then only changing one thing and then seeing an increase in bud size and bud density from that same clone in that same garden after that only one change and observing it is totally bogus
...

It's one thing to experience changes, another to try and explain them .
I do believe in the usefulness of observations even if there is no direct comparison possible other than experience. Nonetheless, such observations should be handled with care before drawing conclusions.

As an example: Midday depression doesn't necessarily mean that the plants start drooping. On the other hand, if you have to water them in midday, then maybe your temperature is too high and the 30 min off time is sufficient to cool the room down?

It could also be that your plants become too 'reduced' (redox state) due photosynthesis, ascorbic acid and other antioxidants accumulate constantly instead of decreasing during afternoon. Hence, stomata remain open, the plants have an increased transpiration, and start drooping.
Maybe this has something to do with hormones you use or 'Power-Bombastic-Megaharvest' you spray, or an undeclared ingredient in your fertiliser... who knows?
Another explanation could be that your plants simply run out of CO2. This again leads to open stomata and so on... but also makes that your plants experience something called photorespiration (which BTW reduces yield).

Now, that's just an example that simple observations may be explained differently.
Obviously, avoiding drooling (seems as if this occurs several times during your grow) increases yield no matter why it occurs whereas avoiding midday depression may not...

Don't put all your bets on midday depression (which occurs rarely indoors and especially not under fluos, Beta is right about that) and keep your minds open!

 

[IntelliGeneS]

Interesting. I understand the desire to replicate the conditions under which the plant evolved. But bear in mind that even though an environment exists and has been exerting selection pressure on an organism, and that organism is adapted to it, it does not necessarily mean that the organism has found the most efficient ways of utilizing the environment (see C3 vs. C4 vs. CAM carbon cycles) nor that that environment is optimum for the organism.

 

[Bubbleblower]

Interesting. I understand the desire to replicate the conditions under which the plant evolved. But bear in mind that even though an environment exists and has been exerting selection pressure on an organism, and that organism is adapted to it, it does not necessarily mean that the organism has found the most efficient ways of utilizing the environment (see C3 vs. C4 vs. CAM carbon cycles) nor that that environment is optimum for the organism.

+1
The truth is we will never know what is optimum and in reality it is always different than in theory.

It's one thing to experience changes, another to try and explain them .

I just keep trying anyway, knowing 99% of the times I will be wrong, I am searching for that 1%.

Lately I use biology to try to explain what happens and physics to try to explain why.
Two sciences I never studied so that looks promising; I am not handicapped by any knowledge
The reason the rubisco break works so well might be because the plants get a chance to recharge their battery improving their logistics.

The key question may be; what happens "if the lights go out"?

 

[Only Ornamental]

...
The key question may be; what happens "if the lights go out"?

True. I don't like the idea of a 'short night' in the middle of the day. Should the 'second night' be too long, then it will mess with the circadian clock and that certainly (based on scientific literature dealing with other plants than 'ours') isn't a good thing.
The question here is: how long does such a night need to be to actually be perceived as one? Depending on the biological process we are looking at, this may be anything between minutes and 2-4 hours.
IF someone really wants to 'give his plants a break', then I propose to reduce the wattage instead of complete darkness. A small fluo or LED suffices to avoid a 'night response'. I wonder if Riddlem's plants would still perform the way they do. If not, then it's most certainly not linked to midday depression but a different (by coincidence) beneficial effect .

 

[Beta Test Team]

I'm not sure we can just assume Riddleme is correct about the growth response; it's possible there isn't one, our minds like to deceive us (which is why using visual observations is not ideal). I wouldn't make such a claim like Riddleme did without more data and at least doing a whole grow - not drawing a conclusions after 24 hours though simple visual observation.

To me, it doesn't make much sense to try to experiment in sub-optimal growth conditions, unless the goal is to research what happens in such sub-optimal conditions.

To test something like the light schedules proposed in this thread, doing so under optimal irradaince and other environmental factors is critical (in my opinion, anyway) for useful data collection. Unless the goal is to grow with sub-optimal conditions, and how to improve them given their limitations. There has been a good amount of research into Cannabis use of radiation over the last few decades, enough to come up with optimal plant growth irradiance goals (over a range, of course).

 

[Reaspberry Rip]

Kind of got off the path here a bit,, but, I can see "Gas Lighting".
In a off beat sort of way,, it is kinda natural if you think about it.

Plant gets more OVER-ALL lighting when sun rises and sets (side lighting). When the sun is about "overhead" the upper part of the plant shades much of the lower to some extent and certainly the main beams (plumbing system). What Riddle may be duplicating is compressing all that reduced lighting (shading)into a 20 minute concentrated time? Dunno,, just stoned & thinking.

Wonder how that works with things like auto flowers though....

 

[Smplfrmr]

Great thread

Great thread

Obviously allot of disciplined research and experience has culminated into a very interesting and educational discussion. I love the scientific approach to our trade and tend to agree that results should be founded in quantitative facts, and observation alone can unfortunately be unreliable because people tend to see what thier looking for, no offense intended by this statement, although I do understand that most of us just grow the way we learned to adjusting technique based on mostly observation of yields and quality of smoke without the resources of a proper lab and as I have to with my limited resources rely on the experiences of others to decide what techniques to incorporate into my grow. After reading all of this thread it's set me on the path of exploring R/FR spectrum as an addition to my light scheme. Fascinating stuff. I think having a practically disciplined and an open mind is key to a great grow. Thanks for the shared knowledge all that contributed here. Somewhere between cutting edge and the K. I. S. S. method is the answer I'm sure.

 

[shaggyballs]

So is anyone doing the red light at night thing?
I think if I get some LED's going it will have this ability.

 

[Lost in a SOG]

Yessir im using far red at sunset.. i have done before but this time im running them on for 14 hours a day all the way through.

Btw, imvho, the intensity has nothing really to do with it health wise assuming your co2 and vpd are adjusted correctly for the ppfd its all about making sure you are supplying the right spectrum to be signalling the right hormones and pigments.. like making sure for one thing the ps1 photosynthetic pathway is getting enough far red all the time or photosynthetic rates drop co2 goes up stomata close more and you can cause some stress there.

Green light boosts co2 absorption as well.

 

[shaggyballs]

More on red light here.