Change light schedule for mother

[Tathagata]

Hi Folks,

Im not sure about lighting. Ive read around but cant seem to find anything that helps this scenario.

A plant is growing under 2 x gro lux 18w fluro tubes. Since its getting close to flowering season, this one is intended to be under lights until next growing season in the hopes it will be female and can be used for cloning.

Initially it was put under a 18 hour lighting schedule (lights on for 18 hours) as this is what my research seemed to indicate was best. The plant is now about 6 weeks old and is going very well.
But I cant see this schedule being maintained.

would it be ok to change the light schedule without having the plant flower. I think its too young for that anyway, but would it hurt the plant to lessen the lighting schedule and how far back can I take it?
could I change it to a 15 hour lightsing schedule? should I do this gradually or just immediately?

Thanks for any help.

 

[coolbud]

If its a regular plant (non auto) , she is going to start flowering only when you give here 12 hours of light / 12 hours of darkness , so my guess is that you can change the schedule but still if you lower the light time it will stretch like a mofo.

 

[BrownThumb]

My plants are flowering at 14 hours. Some are stretching like mofo's, some, not so much. I am thinking they would stretch less with 12x12, but stretch they will, either way. Stretch also seems to be subjective to phenotype and possibly, clone type. Your pheno will have bearing on the stretch, IME.

 

[SeaMaiden]

Coolbud, I have to disagree with you. My experience has shown me that any time the dark phase of the photoperiod is increased sufficiently, pretty much any strain will flip into flower. I have never grown autos, though I did apparently have one seed last year. Grew to 3", flowered, then died. It was the tiniest cola I've ever seen!

In any event, to the OP, what you want to do is interrupt the dark phase of the photoperiod. I like to do two interruptions, an hour each. I match the daylight phase to a late May or early June date, and I do that because everything that's going outside is in the same vegging area/chamber.

Interrupt the dark phase, that's what you've got to do if you plan on reducing that 18/6 by an hour or more. I've played with it a lot, and even an hour increase in dark phase can cause that hormonal switch to be flipped. I have found that doing it in increments mimics nature, and that they will just flip more slowly, just as when you're growing outside. Seems that it would take a good bit of time indoors, as well, and that costs money, right?

I use the very cheap timers from Walmart that allow you to set ON/OFF in 15min increments.

Oh! If you're planning on putting anything outside, this tool is very helpful in calculating the daylight length.
http://astro.unl.edu/classaction/animations/coordsmotion/daylighthoursexplorer.html

 

[BrownThumb]

A couple more thoughts... Some strains will not flower profusely unless they get 13-14 hours of darkness, those being equatorial Sativa strains. I think Indica strains can flower with a longer photo-period than many think. This matters if you believe the rumor of studies suggesting that potency is directly impacted for the better the longer the day during flowering. 13 hours creates more potent smoke than that grown at 12 hours, 14 hours produces more potent smoke than 13 hours, etc. At least, that's a urban legend. Obviously, you can't always use a long day like that and get good flowers, but you can certainly run longer days with at least some Indica/Afghanica strains and probably some Sativa's.

 

[Tathagata]

Thanks for the info so far folks. We are talking a Sativa here, Pineapple Punch to be precise.
The idea of it stretching or flowering is not good, but I guess I can only try.

SeaMaiden, so you think if I bring the schedule down I should compensate by putting the lights on for a time in the dark period?
As an eg; I reduce the time to 15/9 but light the 3 hours in the dark time, then slowly reduce that until its gone? is that right or am I confused?

Perhaps I would be best to just leave it as is. Id rather let her grow.

 

[SeaMaiden]

All you have to do is interrupt the dark phase long enough to prevent the hormonal switches from being flipped. That means that any time during the dark phase an interruption will cause this to occur.

So, let's say you went to 15/9, that's the longest day of the year for you and you have girls you want to put out. At any time during that 9hr dark phase, you can interrupt it with light, and it doesn't even have to be a lot (causing photosynthesis to occur), it just has to be bright enough. A single standard CFL over a couple of OD plants can be it. Shining a flashlight for a few minutes on a nightly basis can be enough (Arabidopsis study, can't find it). So just two 1hr interruptions during that 9hr dark phase will be plenty good to stop induction of flowering.

I hope that makes sense.

The other strain-dependent stuff is much as BrownThumb describes, with Sativas presenting some... interesting dilemmas.

 

[Crusader Rabbit]

Initially it was put under a 18 hour lighting schedule (lights on for 18 hours) as this is what my research seemed to indicate was best. The plant is now about 6 weeks old and is going very well.
But I cant see this schedule being maintained.

Why do you want to change the light schedule?

I have flowered indica dominant strains with ten hours of darkness, fourteen of light.

It is a red wavelength of light that affects the flowering response. As seamaiden said, it doesn't have to be intense. If the goal is to save electricity, you could run your grow lights for photosynthesis and plant growth however long you want, then use a cheap low wattage warm CFL to bath the plant the rest of the time and keep it from flowering.

 

[Granger2]

I think it is likely that at 6-8 weeks you will find pre-flowers under close inspection. Start along main stem from the bottom up. Yes, with 18-6. Please report back. -granger

 

[Tathagata]

I hope that makes sense.

yes, thank you. I like the flashlight idea, cheap is good

Why do you want to change the light schedule?

Well, at the moment she is living in a box with a cheap fluro rig keeping her lit. I worry that neighbours may see light leakage. Reducing the time lights are on makes it easier to blend in with the light we use.

It is a red wavelength of light that affects the flowering response. As seamaiden said, it doesn't have to be intense. If the goal is to save electricity, you could run your grow lights for photosynthesis and plant growth however long you want, then use a cheap low wattage warm CFL to bath the plant the rest of the time and keep it from flowering.

Interesting. And good idea, thanks.

I think it is likely that at 6-8 weeks you will find pre-flowers under close inspection. Start along main stem from the bottom up. Yes, with 18-6. Please report back. -granger

oh dear. So no matter what there is a good chance she will flower anyway?

Ah well, if worse comes to worse Ill let her flower and reap the rewards

I think I just need to get my arse into gear and build a cabinet. I have a plan in mind and should be able to get it done pretty quick if I put my mind to it.
That way I can leave the lights on this schedule. I dont like the idea of mucking about with the light schedule and it sounds like a bad plan to do that.

Many thanks for the help, this is the first plant other than bush weed that Ive managed to get a hold of and I hope to get babies to outdoor grow next summer

 

[Crusader Rabbit]

oh dear. So no matter what there is a good chance she will flower anyway?

Ah well, if worse comes to worse Ill let her flower and reap the rewards

Preflowers will let you identify the sex of the plant, but the plant is not going into full flowering mode. A mother plant can continue on with preflowers.

 

[SeaMaiden]

Yes, an example would be the hearty and hale Purple Cheddar mother I was gifted. She's got her pre-flower fu going strong, all over the place. However, she knows who she is and where she belongs, as evidenced by the properly lobed leaves (5, 7, 9, instead of 3 & 1, which are a sign of 'confusion').

 

[Tathagata]

again, thank you all for your help.
I decided to get my arse into gear and make a grow room.
Its pretty dodgey but will do the trick for now. Cost me about $15 to make because I got the wood for free from a transport company

I put no back or sides on it as the space it was going into was an old refrigerator space and they were already close enough to white.

plan is to redesign it and make another one, perhaps using strip LED lighting (have to look at other micro grows for tips).
If the small amount of light leakage is a problem I can fill it with foam easily enough.

and here is my (hopefully) mother. Cant see any pre-flowering just yet, but she seems to be pretty happy.

 

[StickyStank]

You can keep your schedule of 18/6 but have 2 or 3 low watt cfl lights on to fill in the rest of the 18 hours or anywhere you like, for example the hottest part of a summer day. This is a good way if you want to slow the growth in veg and conserve energy. You can have your main lights on 12 hrs then have the low watt lights fill in the 6 hours.