I use 20/4 for veg and 12/12 flower, I think 4 hours rest is enough but might try 18/6 next time around.
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I use 20/4 for veg and 12/12 flower, I think 4 hours rest is enough but might try 18/6 next time around.
Sorry johnou85, this was not a pole of what photoperiod to use, or even a discussion of "normal" photoperiods. And btw, people need to "rest" plants don't.
Jung3Jim,
Besides a plant having an overall circadian rythym, the ability of a plant to go to flower or to stay in veg is determined by the photoperiod. Marijuanna is a "short day" plant but it is more accurate to say a "long night" plant since the plant measures the dark period. It does this by produceing chemicals (auxims) and hormones (floragen) during the dark period and sending them to the plants apex. These chemicals build up during the dark and are lost again during light. (This sounds famiilar, chk your thread "when does flowering start" of Oct 15th, '09).
The plant can build up these chemicals and go from induction to initiation of flowering in 24-36 hours of darkness. But will fall out of initiation or even the developemental stage of flowering if given light for 14-16 hours. So technically you can extend the overall day length, if you extend the dark period, but cannot extend the photoperiod. So you could theoretically create a "36 hour" day, but it would be 24hrs dark and 12 hrs of light. The results of that extended day would be less growth, due to certian processes taking longer to switch over on the light change and an increased risk of hermephodites due to the unnatural rythym.
This begs the question; why would you want to extend the "grow day"? Especially if it does not improve the final product or slows rather then speeds up flowering time. Time is money (re cost of electrical power) so trying to speed flowering up is what most people concentrate on trying to do, when screwing with the length of the grow day.:D
Hope that makes sence or cents to ya.:thumbsup: -oldmac
An excellent point!Quote:
Originally Posted by oldmac
I concur, plants need to que timing both in light and darkness, and to respirate, not rest. In fact the norm is for plants to increase respiration and burn more carbs in the dark, not rest.
Looking forward to reading this thread!
Take Care, Sal.
There are days when there is 14 or 15 hours of light. There are days when there is 10-11 hours of light. Adjusting the amount of light a plant gets within a one day period may not upset your plant too much.
Or it might f--- it up big time. oldmac is right. Plants have evolved for millenia to grow in certain time periods-- the organelles in plants have DNA that tells them what to do--and all of this is based on the 24 hour day. You can't "train" or "teach" plants to absorb light for 24 or 36 consecutive hours...the chloroplasts aren't like a light switch that just stays on once it's on. The plant's DNA tells a plant how and when to absorb light and convert it to energy...and when not to. And all of this is based on a 24 hour day.
Could you change the plant's DNA so it would tell the chloroplasts to keep converting light energy as long as a light source is available...as in, longer than the 10-15 hours in a "normal" day? Well, yeah. But you'd need to be able to makes changes at the DNA level of the chloroplast...and we're nowhere near that. Or you could try to find a genetic mutation that does what you want, and try to cross breed it back to gain that characteristic. But I've yet to see this sort of plant mutation, so that's not really reasonable. Or you could just keep plants under artificially adjusted "days" of 48 hours with more light, and wait for nature to take its course and evolution to take place. In a few hundred thousand years or so, you will probably get what you want. Evolution of this type is a very slow process. The bottom line is that "changing" the length of the day is not going to work.
Now, changing the amounts or types of light within a 24 hour day, or working within light parameters that a plant is used to...that could do something. If you flipped a plant from 24/0 veg to 15/9 or 14/10 flower, you might get more rapid growth...the plant would, theoretically, be converting about 15-25% more light to energy. But I suspect that the DNA in most plants wouldn't buy that either, and you'd get sudden halts in growth, hermies, or both. Might be worth a try, though.
"Hours of uninterrupted Darkness" is the accepted standard for proper photoperiodic triggering, But I do think that there are "DAY" light DNA sequences. I tend to think of them as sequences that are used at night, but they are shortened versions of them with light driven start/stop receptor sequence sites.
Take care, Sal.