Flowering with 14 hours light

Okay, looks very similar. I don't know what would happen if you used far red after initial stretch. Maybe foxtailing. I did get a lot of foxtails when I used an incandescent blacklight for 5 minutes end of day before.

I use a far red lamp in my garden, it turns on about 10 minutes before the HPS turns off and stays on for about 20 minutes, I do a 13 1/2 hour light cycle. Any foxtailing that I have gotten I have blamed on other things. The light cycle seem to only take about threedays off the finish time but I have had problems with some strains that seem to be on the verge of finish and start putting out more buds. In that case I put them in the bathroom with a 10/14 cycle and they usually ripen within a few days and the buds are just as big and hard as the ones that I didnt do the cycle on. (got 6 plants in the bathroom now).

I'm using 13 hours now and it's working great. I know the thread title is about 14 hours but I don't actually want to use that many, or even 13.5. 13 seems just about right. I'm getting noticeably faster growth than with 12. At 6 weeks flower the buds look like 7 weeks with 12.

When I first read about using far red there was someone that claimed to be only giving their plants 8 hours of dark a day and for some reason they used the far red both at the begining and end of the dark cycle. I have not tried to go under 10 1/2 hours of dark but I do have some new lights coming so I may do a side by side grow.

I thought the use of far red( or is it red) stops the stretch? It is to do with when the sun sets and the red wavelengths are the longest and that's what the plant absorbs to know that night is approaching?

Someone did explain it to me but my memory is awful.

Growmau5 done a video on his far red and thought it shortened flowering times.

I think it just makes the plants aware to switch to night sooner. Because doesn't it take them like 1-2 hours to switch to their night routine?

JDMase said:

I thought the use of far red( or is it red) stops the stretch? It is to do with when the sun sets and the red wavelengths are the longest and that's what the plant absorbs to know that night is approaching?

Someone did explain it to me but my memory is awful.

Growmau5 done a video on his far red and thought it shortened flowering times.

I think it just makes the plants aware to switch to night sooner. Because doesn't it take them like 1-2 hours to switch to their night routine?

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The THEORY is that far red at end of day = 2 additional hours of darkness. It has never been scientifically proven. What HAS been proven is that it makes the stems elongate as if the plant was in shade and stretching for light. End of day RED light counteracts the stretching effects of far red. And no, it doesn't shorten flowering times like Growmau5 said. I tried it with 12/12 and it still took 10 weeks like always. It also made my plants stretch like crazy, had to cut the tops off.

Pfr (phytochrome far red receptors) are converted to Pr in darkness, or by far red light. So, although far red light hastens the conversion, it is not alltogether the same as an additional two hours of dark as there are other processes that would occur in that time.


All that there is to be gained by far red light exposure is a quicker onset to flowering on the initial "night" of flower inducing "lights out". Beyond that, it's shear redundancy.

Odin* said:

Pfr (phytochrome far red receptors) are converted to Pr in darkness, or by far red light. So, although far red light hastens the conversion, it is not alltogether the same as an additional two hours of dark as there are other processes that would occur in that time.


All that there is to be gained by far red light exposure is a quicker onset to flowering on the initial "night" of flower inducing "lights out". Beyond that, it's shear redundancy.

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I've also read that it only tales about 30 minutes for darkness to convert the phytochrome, not 2 hours. It has never been scientifically established how long it takes but in certain experiments I read about they found that it appeared to be more like 30 minutes. So you might gain half an hour but so what? Not really worth the stretching and lack of branching.

@BobCajun That information is incorrect. It takes far longer for the Pfr to convert to Pr. If it only took 30 minutes then flowering would only require 30 minutes of darkness each night. Pfr inhibits flowering, it is the point at which Pfr levels are insufficient to inhibit flowering that the onset of flower is triggered.

Odin* said:

@BobCajun That information is incorrect. It takes far longer for the Pfr to convert to Pr. If it only took 30 minutes then flowering would only require 30 minutes of darkness each night. Pfr inhibits flowering, it is the point at which Pfr levels are insufficient to inhibit flowering that the onset of flower is triggered.

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Well I meant whatever people think takes 2 hours. Because 2 hours darkness also doesn't induce flowers.

@BobCajun Yeah, all the far red does is hasten the transition of Pfr to Pr. It doesn't hasten the metabolic pathways initiated by insufficient Pfr (to inhibit flowering). It's only on that first "night" that hours are shaved off, after that, the shorter "day" and longer "nights" maintain flower/low Pfr.

It may trigger a more "aggressive" response to flowering by dropping Pfr rapidly and to lower levels in the given time (again, first night).

Odin* said:

@BobCajun Yeah, all the far red does is hasten the transition of Pfr to Pr. It doesn't hasten the metabolic pathways initiated by insufficient Pfr (to inhibit flowering). It's only on that first "night" that hours are shaved off, after that, the shorter "day" and longer "nights" maintain flower/low Pfr.

It may trigger a more "aggressive" response to flowering by dropping Pfr rapidly and to lower levels in the given time (again, first night).

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Why would it only work on the first night? It works every night you do it. But I just don't believe it equates to 2 more hours of darkness.

@BobCajun It would only be effective that first night because prior to that it was exposed to long days and short nights. Those long days maintain very high ratios of Pfr to Pr. After that initial "night" (to initiate bloom) the plant(s) will no longer be subjected to such long "days" (unless there is a "fuck up", resulting in "reveg"), as well as longer nights, both fascilitating greater Pr to Pfr ratios. Only in onset would it benefit, after that Pr to Pfr is maintained by the light schedule.

Odin* said:

@BobCajun It would only be effective that first night because prior to that it was exposed to long days and short nights. Those long days maintain very high ratios of Pfr to Pr. After that initial "night" (to initiate bloom) the plant(s) will no longer be subjected to such long "days" (unless there is a "fuck up", resulting in "reveg"), as well as longer nights, both fascilitating greater Pr to Pfr ratios. Only in onset would it benefit, after that Pr to Pfr is maintained by the light schedule.

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Okay maybe it's like giving them 24-36 hours darkness the first night then. Some people do that. I hadn't heard anything about the first night only, just every night with the EOD far red. Personally I find it doubtful but I guess it's conceivable. Is that what the vendors say about the initiator? Where did you get that from? It doesn't actually say that here. Says every day. I don't believe it works like they say. You can flower with 13-14 hours without the initiator light anyway. Just my opinion, don't know for sure. But what they don't tell you is that the far red will cause crazy stretching and reduced branching. Not really worth it.

The guys trying to sell you a light aren't going to say that it's "essentially useless". The far red every "night" is a gimmick, nothing more. Plenty of info out there on the subject (I've shared some here already).

Odin* said:

The guys trying to sell you a light aren't going to say that it's "essentially useless". The far red every "night" is a gimmick, nothing more. Plenty of info out there on the subject (I've shared some here already).

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Would it be possible to get an explanation on what happens with plants in nature after the sun goes down? Don't they get a daily dose of the far red light too?

Eagle-ize said:

In my experiences playing with longer photoperiods in the reproductive (flowering) phase, the longer hours produced a bit more weight with slightly larger buds but it didn't double my yield. They did, however, seem to finish a bit sooner than the plants on the 12/12 schedule. At the time, I had already made the transition to LED so...

A1000w HID radiates IR light for a short period after it is turned off so maybe we can speculate that there is some correlation there.
There are many studies on EOD IR exposure for plants, however, I have found nothing substantial related to cannabis.

I believe the key to the yield directly related to the amount of total light the plant gets (daily light integral). If IR is stated to have
photomorphogenic influence to promote flowering responses, it may be exactly what the plant needs to counteract the longer photoperiod.
After all, it is what occurs in nature.

Nice find sir! This topic is interesting to me so please share your thoughts.

Cheers!

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IR nm bands are not used by plants (760 nm - 1400nm) Far red is what puts the plants to "sleep".....like around 710 -750nm with 730nm being the actual most effective nm band...or at least the one used most......If I remember right it's like plant effective from like 722 to 738nm..in a positive and negative, or "complete" bell curve....

@BobCajun

I got some of those 730nm 10w & 20w "flower initiators" a few years back. I found that the return in gain was not able to cover the cost of use when tied to 2 hrs of lighting increase. I've sold most of them to folks that wanted to try it them selves.....they aren't using them anymore either!

Longer bloom times also cause more unstable plants and in turn more plant problems in bloom then with shorter time like 11.5 to 11 hrs of ON lighting times...This has been proven by folks like DJ Short and others. Plants are more likely to herm with longer lighting bloom times.

I use a diminishing lighting time with high and pure sativa's to get a better and more positive finish.

I find your simply not gaining enough to justify a lighting time over 12/12....

Eagle-ize said:

Would it be possible to get an explanation on what happens with plants in nature after the sun goes down? Don't they get a daily dose of the far red light too?

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Exposure of FR in nature, is by very low amounts over an extended period. That period last for about, right before the sun goes over the horizen, to actual complete darkness. About 2 hrs.
That's why 5 - 10 min exposures of the 730nm band will completely shut the plant down and you can have that extra "on light" time.

The plant in darkness undergoes a cellular peptide change that allows the plant to use the intense light of day at it's best ability. Till it begins to slow down that ability by about 30% due to the plant hitting the "light saturation point". It's at this point, that the plant begins to change on the cellular peptide level to "protect" it's self from that intense light of the day.

It actually happens at an earlier time then many people think. The use of "extra" lights on times, is allowing for some recovery of this "lost light effectiveness". Another method of "recovery" of this "lost effectiveness", is the use of Co2! Technically speaking in simple terms. The Co2 allows the plant to operate at that "peak" effectiveness longer! I have found it as more effective in recovering that lost 30+% of the growth, lost to that "light saturation point"....

Yet again, cost effectiveness comes into play and the added things to dial in,,, tend to overweight my need to actually use it...

In the end. NOT using these things and simply dialing in your feed to strain and the spectral use of lighting. Will supply a superior product, with results closer to actual plant potential, with higher quality.......the opposite end of the light spectrum is far more important!

Think UV!

Dr. Who said:

IR nm bands are not used by plants (760 nm - 1400nm) Far red is what puts the plants to "sleep".....like around 710 -750nm with 730nm being the actual most effective nm band...or at least the one used most......If I remember right it's like plant effective from like 722 to 738nm..in a positive and negative, or "complete" bell curve....

@BobCajun

I got some of those 730nm 10w & 20w "flower initiators" a few years back. I found that the return in gain was not able to cover the cost of use when tied to 2 hrs of lighting increase. I've sold most of them to folks that wanted to try it them selves.....they aren't using them anymore either!

Longer bloom times also cause more unstable plants and in turn more plant problems in bloom then with shorter time like 11.5 to 11 hrs of ON lighting times...This has been proven by folks like DJ Short and others. Plants are more likely to herm with longer lighting bloom times.

I use a diminishing lighting time with high and pure sativa's to get a better and more positive finish.

I find your simply not gaining enough to justify a lighting time over 12/12....

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So you didn't notice much increase in yield with 14 hours light? How long did it take to ripen with that cycle anyway, extra week?

BobCajun said:

So you didn't notice much increase in yield with 14 hours light? How long did it take to ripen with that cycle anyway, extra week?

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Not enough to justify spending the extra cash on all the electrical. Say around 15+ %. The thing being is that around here. The more elec. you use. The higher cost bracket you jump into,when in a residential use classification. I'm not and it's still too much..
Around that but, not as much as I thought it would...I got only days in difference...

Shorter times are faster, yet once you go below 10/14. You really start seeing reduced yields....