Flowering PHOTO PERIOD 12-13 Hours Experiment

[B. Friendly]

This time I am going to go 12.5 hours of light during flower and next run I'll try 13 hours.

QUESTION: if photosynthesis and light are responsible for girth, then is letting your plants have an extra 30-60 minutes at night beneficial. From 12 hours to 12.5 or 13 hours,
girls will still maintain flower production with some more minutes??????

Anybody ever try this? if so how did it work out?

Will yeild go up?

 

[B. Friendly]

anybody ever tried a 13 hour day and 11 hour night during flower?

 

[supermanlives]

nope but i have always wondered.

 

[organicsquirrel]

I have a feeling that this will be very strain dependent... You may want to run it with a few indicas and a few sativas. I'd be very interested in seeing the results of an experiment such as that.

I bet some strains will flower out, I bet some won't. Some may partially flower, but if you found a strain that didn't care as much it's possible that you could add some weight. An extra hour is 1/12 ~ 8.3% more light. Would that equal maybe 5% more yield? Probably not, but possibly.

I have a feeling you wouldn't be the first person to try this out, there may be experts that hopefully chime in, eh?

 

[B. Friendly]

I have a feeling that this will be very strain dependent... You may want to run it with a few indicas and a few sativas. I'd be very interested in seeing the results of an experiment such as that.
may be experts that hopefully chime in, eh?

got a Purple Kush indica and an Original Haze x Skunk1 for sativa. Not ideal but some variation in strains

12.5 hours of light, this round and 13 hours next round

 

[B. Friendly]

Oh I have done 14 hours with alot of diff indicas and they all turned to flower
That's why I am confident that at 12.5 and 13 hours of light they should stay in FLOWER the concern is what will happen to yeild?????????

 

[basspirate]

I am absolutely no expert, but I was recently looking into a 12/6 light cycle and found some posts about this subject.

As for what will happen, I am unsure but I believe that part of the importance of the dark cycle is to allow the plant ample amounts of time to metabolize all the energy it was building during the light period. I would assume that each strain, or maybe even each plant has a specific pocket that you could hit to really at least maximize the cycle.

If it works for you though, I might have to try it...anything to put some more bounce in the ounce!! good luck capn!

 

[foomar]

Ran the whole very mixed flower room on 13 light hours by a timer mistake for over a year , no problems seen , would not have noticed any extra yield.

 

[B. Friendly]

Ran the whole very mixed flower room on 13 light hours by a timer mistake for over a year , no problems seen , would not have noticed any extra yield.

if the photo period changed a change to growing style in compansation might add yeild,
If I remember correctly Tomatoes are yeilding their highest in Greenhouses that run all year during the SUMMER months, reason being more light equals more yeild. This is an industry standard concensus that for every 1% increase in light a direct 1% increase is seen in yeild.
therefore by giving more food, or slightly changing temps up or down, possible lower RH. One of these in corrolation to day lenght will increase yeild if MJ has anything in common with Tomatoes and they do.

So I am gonna talk to some greenhouse growers and research to see if there is a formula that longer day lenght follows to increase yeild.

or I could find that no benefit is gained from longer day length.

 

[bushwakka]

my feeling has always been that 12/12 is right in the middle for the plants, by shortening the night it gets a signal to finish up quicker so you may yield less but get a slightly quicker finish, it may also encourage any hermy traits as it feels the need to replicate in more of a hurry(if this makes sense).

 

[Tropic]

I remember reading about this in Franks and Rosenthal's Indoor Marijuana Growing Guide years ago.
According to them, reducing light hours weekly during transition to flower allows the grower to determine a trigger point for different strains/plants (which can later be very useful for putting indoor pre-vegged plants outdoors). This has been discussed recently (someone asking why 12/12 for flower). I don't remember reading about extra yield, but I'd be tempted to think that more light hours = more photosynthesis, and to a certain extent, more yield, but how much?

 

[B. Friendly]

I remember reading about this in Franks and Rosenthal's Indoor Marijuana Growing Guide years ago.
According to them, reducing light hours weekly during transition to flower allows the grower to determine a trigger point for different strains/plants (which can later be very useful for putting indoor pre-vegged plants outdoors). This has been discussed recently (someone asking why 12/12 for flower). I don't remember reading about extra yield, but I'd be tempted to think that more light hours = more photosynthesis, and to a certain extent, more yield, but how much?

what I am doing now is going 13 hours with my mh turning on at 11.54am and off at 12.37am
while my hps is turning on at 12.10pm and off at 12.55am

so it's like on bulb turns on and the the other turns on 15 minutes later,
and on bulb turns off and the other follows about 15 minutes later,
so it's like the sun coming up and going down.

who knows if this matters??????

 

[FreezerBoy]

12/12 is just a "one size fits all" solution. Few plants actually need 12 hours of dark.

 

[B. Friendly]

well my Purple kush girls are nearly done,
having close to 13 hours of light during flower was not a problem

I just would have to do a crazy controlled experiment,
so all i got is my intuition and that tells me, based on Photosynthesis that more light is a good thing

besides 12/12 is just rule of thumb

experiment peeps and find out what your girls like best..................

 

[budlover123]

I've always wondered if 12/12 typically triggers flowering, or if maybe the 12 hours of light or dark alone could do the trick, if 12 on 6 off worked the plants would only half the sleep time, that could potentially have some great results maybe if it worked, People usually assume that a 24 hour schedule is important because it's natural but maybe it doesn't matter.

 

[asde²]

i
If I remember correctly Tomatoes are yeilding their highest in Greenhouses that run all year during the SUMMER months, reason being more light equals more yeild. This is an industry standard concensus that for every 1% increase in light a direct 1% increase is seen in yeild.

dunno where you got that 1% for 1% from.. to me it sounds like a bullshit but the other thing is correct BUT;
MORE LIGHT MEANS HIGHER INTENSITY and not LONGER LIGHT PERIOD in this case.. ofc 20 hours of 1x600w hps equals the amount of light for 10 hour of 2x600w hps but thats not the point - still you referring to it

 

[B. Friendly]

dunno where you got that 1% for 1% from.. to me it sounds like a bullshit but the other thing is correct BUT;
MORE LIGHT MEANS HIGHER INTENSITY and not LONGER LIGHT PERIOD in this case.. ofc 20 hours of 1x600w hps equals the amount of light for 10 hour of 2x600w hps but thats not the point - still you referring to it

first look up the term BOTANY,
then buy a Botany Text Book,
then look up the equation for Photosynthesis,
then learn it,
then tell me 1% more light does not translate into 1% more yeild.

then look at the Hot House Industry,
realize that BC vegetable crops here get the highest annual yeilds per meter of space in the whole wide world

then and from then on, don't talk until you know what you are saying.

looks like you don't recognize bull shit when you see or smell it.

that's all folks.

 

[ZAPOT]

I think it would be more beneficial to concentrate giving different wavelengths in different periods of time so that the plant "thinks" it is getting enough dark period but in reality it aint getting it. Instead of that it is forced to work on in any aspect suitable. Do you think that would be possible to achieve?

Another point of view: give a plant the very same wavelengths as the sun gives (the change of the light) during the whole day but in shorter intervals so a whole day for a plant is shorter in reality but it doesn´t know it. Plant gets it´s natural cycle of life. You should use boosters.

Would there be any point in doing just the opposite: lengthen the day and night (for a change) to actually get faster and better yields?

Actually it could be a good thing to mix two aspects that i´ve mentioned in this post. It would be essential to know right ferting cycles.

btw. always have a control group when experimenting to be able to see any results. Plus one eye is not better then two eyes etc!

 

[GIS]

This is really interesting. I love experiments, and I've always wondered about the lighting schedule as well. Like would it be better to slowly dial back the hours more akin to how nature works than the abrupt change from 18 to 12 for instance. Can't wait to see what comes of this!

 

[B. Friendly]

This is really interesting. I love experiments, and I've always wondered about the lighting schedule as well. Like would it be better to slowly dial back the hours more akin to how nature works than the abrupt change from 18 to 12 for instance. Can't wait to see what comes of this!

A buddy did the dial back thing one hour per day all the way down to 12 hours. His comment was that it just took longer to finish flower cuz the extra days to dial down.

but 13 hours of light every night for the entire flowering period was not a problem at all. For my Purple Kush girls in fact they showed no negative signs. and the herb so far is great.

10.5 weeks of flower so far and the PK girls are looking good, will let live for another week for sure maybe 2????

I can say my Original Haze x Skunk1 I believe would have preferred less lighting at 12 hours per night of light. These girls stunted and did not finish for me.