What do you think of 24/0 for the light?

[AutoWonders]

I have the 240w kingbrite led in the tent and was planning to do 24/0 but I have read a few people recommending not doing 24/0. What do you think? Would 22/2 or 20/4 or 18/6 be better or do you think if I can keep the temperature in the tent right that 24/0 would be the best to do on there?

I vote for 20/4, which is what I run for a light schedule.

 

[AutoWonders]

Some people say that the Ruderalis is used to 24/0 light. I think that is ridiculous. I have nor researched it;

Auto's are classified as a 3-C plant. That means NO light preclusions. Ruderalis is found in harsh climates.

 

[Builder0101]

Yep

Auto's are classified as a 3-C plant. That means NO light preclusions. Ruderalis is found in harsh climates.

 

[Olderfart]

I don't have as much experience as others here do, but I will chime in anyway. In my grow, I tried both 24/0 and 20/4, and elected to stay with 24/0 because doing that kept temperature and humidity under better control. My grow was in winter in central BC, so I found temps went too low and wet if the lights were off for four hours. I could have dealt with this by adding a heater, but elected not to. The plants didn't seem to care much one way or another as far as I could tell, but I was dealing with excess light during much of the grow.

Any of the 24/0, 20/4, or 18/6 regimes can work fine. Just choose one and dial it in. Electricity costs are not a big deal in a small home grow with LED's. In my grow, the difference between 24/0 and 20/4 would have been less than $10 for the whole grow, maybe less than half that. Any saving in LED consumption would have been cancelled if I used an electric heater to keep temps and humidity in range during 20/4.

 

[Son of Hobbes]

Auto's are classified as a 3-C plant. That means NO light preclusions. Ruderalis is found in harsh climates.

C3 plants technically The problem with the C3 argument is that the observed gains, however anecdotal, have not really shown any actual gains (or negligible gains) in potency/weight versus light cycles that introduce a dark period. About 85% of plants on the earth use the C3 pathway for photosynthesis, yet the majority of the earth does not see plant life growing in 20+ hours of sunlight per day either. "More" is not necessarily better, even if there is capacity for it to do so.

Introduce Daily Light Integral (DLI,) and now we're talking thresholds of plants ability to even use certain amounts of light energy in a 24 hour period. This is actually where I think an argument could be made for 24/0 versus 18/6, if you're using low PAR/PPFD lighting, or the wrong spectrum, then the additional hours of lighting is making up for the lack of efficiency, intensity, improper spectrum, etc. Using budget lights from amazon versus a high PPFD full spectrum light, etc.

 

[Death The Cultivator]

C3 plants technically The problem with the C3 argument is that the observed gains, however anecdotal, have not really shown any actual gains (or negligible gains) in potency/weight versus light cycles that introduce a dark period. About 85% of plants on the earth use the C3 pathway for photosynthesis, yet the majority of the earth does not see plant life growing in 20+ hours of sunlight per day either. "More" is not necessarily better, even if there is capacity for it to do so.

Introduce Daily Light Integral (DLI,) and now we're talking thresholds of plants ability to even use certain amounts of light energy in a 24 hour period. This is actually where I think an argument could be made for 24/0 versus 18/6, if you're using low PAR/PPFD lighting, or the wrong spectrum, then the additional hours of lighting is making up for the lack of efficiency, intensity, improper spectrum, etc. Using budget lights from amazon versus a high PPFD full spectrum light, etc.

Well said. I've been thinking ever since the previous conversation in the watts per sqft thread that time vs. intensity is the determining factor in which light schedule should be used.

Unfortunately a PAR meter cost as much as high end LED fixtures so it's cost prohibitive but it could answer any Grower's question of how much light vs how long. DLI and PAR invalidate watts as hopefully lights will evolve enough to use less watts but still provide the necessary PAR.

 

[Son of Hobbes]

Well said. I've been thinking ever since the previous conversation in the watts per sqft thread that time vs. intensity is the determining factor in which light schedule should be used.

Unfortunately a PAR meter cost as much as high end LED fixtures so it's cost prohibitive but it could answer any Grower's question of how much light vs how long. DLI and PAR invalidate watts as hopefully lights will evolve enough to use less watts but still provide the necessary PAR.

I've been super baked in quarantine and been reading more about the circadian rhythm of plants. I've added a few blurbs in parenthesis of my own.

Plant circadian rhythms are observable biological oscillations (in laymen, cell signaling based on time changes) that occur in a 24 hour period.

They are based on an endogenous (originating from) transcriptional CLOCK (in this case, stands for Circadian Locomotor Output Cycles Kaput,) a gene encoding a basic helix-loop-helix-PAS transcription factor believed to affect both the persistence and period of circadian rhythms,) which itself is reinforced by environmental cues such as variations in light and temperature.

Now give this some food for thought:

Plants use sugars to tell the time of day, according to research published in Nature today.


Our research shows that sugar levels within a plant play a vital role in synchronizing circadian rhythms with its surrounding environment

Alex Webb

Plants, like animals, have a 24 hour 'body-clock' known as the circadian rhythm. This biological timer gives plants an innate ability to measure time, even when there is no light - they don’t simply respond to sunrise, for example, they know it is coming and adjust their biology accordingly. This ability to keep time provides an important competitive advantage and is vital in biological processes such as flowering, fragrance emission and leaf movement.

BBSRC-funded scientists from the University of Cambridge Department of Plant Sciences, are studying how plants are able to set and maintain this internal clock. They have found that the sugars produced by plants are key to timekeeping.

Plants produce sugar via photosynthesis; it is their way of converting the sun’s energy into a usable chemical form needed for growth and function.

This new research has shown that these sugars also play a role in circadian rhythms. Researchers studied the effects of these sugars by monitoring seedlings in CO2-free air, to inhibit photosynthesis, and by growing genetically altered plants and monitoring their biology. The production of sugars was found to regulate key genes responsible for the 24 hour rhythm.

Dr Alex Webb, lead researcher at the University of Cambridge, explains: “Our research shows that sugar levels within a plant play a vital role in synchronizing circadian rhythms with its surrounding environment. Inhibiting photosynthesis, for example, slowed the plants internal clock by between 2 and 3 hours.”

The research shows that photosynthesis has a profound effect on setting and maintaining robust circadian rhythms in Arabidopsis plants, demonstrating a critical role for metabolism in regulation of the circadian clock.

Dr Mike Haydon, who performed much of the research and is now at the University of York added: “The accumulation of sugar within the plant provides a kind of feedback for the circadian cycle in plants – a bit like resetting a stopwatch. We think this might be a way of telling the plant that energy in the form of sugars is available to perform important metabolic tasks. This mirrors research that has previously shown that feeding times can influence the phase of peripheral clocks in animals.”

Article credited to Biotechnology and Biological Sciences Research Council (BBSRC)

https://www.cam.ac.uk/research/news/researchers-show-how-plants-tell-the-time

So if this is the case, the circadian rhythm (basic internal clock that it says "okay, this is what my normal routine should be, let's see how it goes") of plants (including ruderalis and ruderalis hybrids) may be (suggested by the article above) regulated by sugar levels (brix) in plants in the time keeping schedule of the rhythm.

So another factor may be (to complicate things further) the brix level of the plants themselves, not just in proper nutrition/feeding of the plant, but having high/proper sugar levels to properly regulate plant function.



Where is @JM ? That guy can talk high brix all day.

 

[jdm61]

Brix, eh? Is it time to bring the beer guys into the discussion?

 

[MesaBoogie]

Brix, eh? Is it time to bring the beer guys into the discussion?

It's always time for beer !

 

[Mañ'O'Green]

It's always time for beer !

If you are talking Brix you are talking Ales!