10/14

[gypski]

I was looking at the photo-period graph in Marijuana Botany, and according to the graph, maximum THC production occurs with about 10 hours of day light. Doesn't that seem logical that when you are flowering, you should reduce the light period to 10 hours during the last 3-4 weeks for maximum effect? :D

[bigsby]

See I've been interested in this too but wiser growers than I (doesn't take much really) have told me that screwing with the photo period risks stressing plants into hermies. But it is the same theory behind the 48 hours of darkness before harvest. I mean, the plant thinks it's the fall season so it expects the days to get shorter and shorter, no?!

[oldmac]

Hey gypski,

Here's an idea that some grower's use that might tickle your fancy.
Adopt a "20hr day" for your plants and use 10/10. For every 6 calender days you have 7 "20hr days"; so for a plant that has say an 8 week (56 calendar days) flower time you can cut that down to 7 weeks (abt 48- 49 calender days).

The "20 hr day" could be even 12/8 or 11/9, since most strains won't fall outta flower @ 8hrs of dark, tho you may want to use 36-48 hrs of darkness between veg and flower to kick start the induction phase of flowering.

Yo bigsby,

That leads me into this, 48 hrs of dark at the end of the flower period, IMHO, does not add anything to the plant. It won't help with trichome finish or bud growth. I think this myth got started by someone not understanding the use of 36-48 hours of a dark period between vegative and flowering. This btw does have an effect on how fast a plant makes that transition.

Hope this helps and is maybe some food for thought. :thumbsup:
OM

[bigsby]

People are always teaching me something here. I love the low key nature of these forums.

Thanks for the input oldmac. The 20 hour day approach is interesting. But you would need a 20 hour timer to make this work. I can't see doing this manually. I'm guessing that some of the newer digital timers or higher end greenhouse timers would permit this kind of manipulation.

[gypski]

Hey gypski,

Here's an idea that some grower's use that might tickle your fancy.
Adopt a "20hr day" for your plants and use 10/10. For every 6 calender days you have 7 "20hr days"; so for a plant that has say an 8 week (56 calendar days) flower time you can cut that down to 7 weeks (abt 48- 49 calender days).

The "20 hr day" could be even 12/8 or 11/9, since most strains won't fall outta flower @ 8hrs of dark, tho you may want to use 36-48 hrs of darkness between veg and flower to kick start the induction phase of flowering.

Yo bigsby,

That leads me into this, 48 hrs of dark at the end of the flower period, IMHO, does not add anything to the plant. It won't help with trichome finish or bud growth. I think this myth got started by someone not understanding the use of 36-48 hours of a dark period between vegative and flowering. This btw does have an effect on how fast a plant makes that transition.

Hope this helps and is maybe some food for thought. :thumbsup:
OM

OM sounds interesting, but I agree with bigsby on arranging for the twenty hour day. What's a few days longer waiting, I'm not in it for the money per se. When I hit a place I know I will be staying for a period of time, I'll try some of that tweaking. :thumbsup:

[WashougalWonder]

Hey gypski,

Here's an idea that some grower's use that might tickle your fancy.
Adopt a "20hr day" for your plants and use 10/10. For every 6 calender days you have 7 "20hr days"; so for a plant that has say an 8 week (56 calendar days) flower time you can cut that down to 7 weeks (abt 48- 49 calender days).

The "20 hr day" could be even 12/8 or 11/9, since most strains won't fall outta flower @ 8hrs of dark, tho you may want to use 36-48 hrs of darkness between veg and flower to kick start the induction phase of flowering.

Yo bigsby,

That leads me into this, 48 hrs of dark at the end of the flower period, IMHO, does not add anything to the plant. It won't help with trichome finish or bud growth. I think this myth got started by someone not understanding the use of 36-48 hours of a dark period between vegative and flowering. This btw does have an effect on how fast a plant makes that transition.

Hope this helps and is maybe some food for thought. :thumbsup:
OM

I don't get the 20 hour day........must not be stoned enough.......;)

If one thinks of the homeostasis of a plant that lives in an environment......
Spring brings longer days, summer of course has the end of one and the beginning of the reduction of light, signaling time to reproduce.
Fall brings the shortest days and the plant still has not succeeded in reproduction, so it will try harder to collect pollen and produce more chemicals to attract pollen.

It is all as simple as that.

I think changing lighting to this and that sends signals to the plant. When we light stress during the dark phase is when we get the intersexual and hermaphroditic displays. A gradual change is much different.

As things stand now, I may just experiment with that, as I am going to expand a little and have a different veg area with a different lighting schedule for one specific plant.........Stupid to spend so much to make one plant do it's thing, but if I succeed, I will revive some of my young adult years with real Thai.

These are opinions, not facts, so if you disagree, be my guest, just theory that needs to be proven.

[oldmac]

Hey all,

First to do a 20hr day, all it takes is a recycle timer that is capable of 10-12 hrs on and 10-8 hrs off. Sentenial DRT-1 is capable of this.
The real pain in the butt is you need to have the fexiblity to tend your plants while the lights are on, and that is constantly changing.

Next try to understand that when we talk about "light stressing" a plant, it's interrupting the dark period...with light. Changeing a plant's photoperiod, when done correctly will not stress the plant. When a plant is in vegative mode, lenghten or shorten the photoperiod (lights on) time to what you want, while the lights are on. When a plant is in flower mode, lenghten or shorten the dark period (lights off) to what you want, while the lights are off. This can be done all at once, no need to gradually change it. No light stress involved. In fact, trying to change photoperiods gradually, you are more likely to screw up.

While I understand, most people here are hobbyists and not in it for the money....growing does cost money...and time is money. Plus the 20hr day routine I told you abt was just food for thought or to get you to do some mental masturbation. :D

As to a plant's homeostasis or as some might call it's cicadia rhythm, plants in general and mj in particular are very adoptive. The "enviorment" we are talking about here is indoors, and the gradual light changes of outside natural light really don't apply. We are already using light schedules that take advantage of the fact we know mj is a "long day plant" and we can control how long it will veg. And we control when it will flower, and even have a bit of control over when it will finish.
OM

[Dutch Pimp]

As to a plant's homeostasis or as some might call it's cicadia rhythm, plants in general and mj in particular are very adoptive. The "enviorment" we are talking about here is indoors, and the gradual light changes of outside natural light really don't apply. We are already using light schedules that take advantage of the fact we know mj is a "long day plant" and we can control how long it will veg. And we control when it will flower, and even have a bit of control over when it will finish.
OM


well said!...:thumbsup:...we got maryjane by the short hairs...:smokin:

[bigsby]

So along the same lines, what about light manipulation whereby a grower increases lighting during early flower and then decreases towards the end. Say going from a 400w in veg and early flower, then up to a 600w for peak flower and then back down to 400w for the end of the grow. Times remain static but light intensity changes. Just noodling on it.

[oldmac]

Gypski, hope you don't mind my anwsering questions here, not looking to jack your thread.:)

Yes Bigsby, noodling things is good and so is varying light intensity thru out the grow. Vegging plants need less light but blue dominate, while flowering needs much more intensity and more red dominate. I would not go down in amount of light for end of flower tho, I might try adding a light that could give better trichome finish. Adding some UVb (use great caution with this) or look to change the spectrum for the last week or two, using a bulb that is in the 10,000k range. Something like a PSMH, or CMH or even a MH in that range. It makes a big difference with getting trichs to turn amber.:D
OM

[gypski]

Gypski, hope you don't mind my anwsering questions here, not looking to jack your thread.:)

Yes Bigsby, noodling things is good and so is varying light intensity thru out the grow. Vegging plants need less light but blue dominate, while flowering needs much more intensity and more red dominate. I would not go down in amount of light for end of flower tho, I might try adding a light that could give better trichome finish. Adding some UVb (use great caution with this) or look to change the spectrum for the last week or two, using a bulb that is in the 10,000k range. Something like a PSMH, or CMH or even a MH in that range. It makes a big difference with getting trichs to turn amber.:D
OM

I started it for that reason, just to get different opinions that I can try or relate. :thumbsup:

[canniwhatsis]

I think this myth got started by someone not understanding the use of 36-48 hours of a dark period between vegative and flowering. This btw does have an effect on how fast a plant makes that transition.

Hope this helps and is maybe some food for thought. :thumbsup:
OM

More food for thought is that this dark period before flowering is strain dependent.


I've alway's used 36 hours of dark before shifting from 18/6 to 12/12,

While I don't have a full grasp on it's effect, I can say at least for my blueberry strain it was a detriment.

I did a blind grow resulting in high stretch, and 2 day's delay in the onset of flowering in the "Dark cycle" girl

The 2nd plant was simply swapped to 12/12, and actually received an EXTENDED light cycle! around 24-28 hours, most was under the blue of the MH (14-16 hours), the latter was under the red of HPS.


I'm not going to actually log this grow, so it's just speculation ;) See sig line.

[bigsby]

Vegging plants need less light but blue dominate, while flowering needs much more intensity and more red dominate.

Thanks oldmac, I do have a grasp of the basics... ;) I've been reading up on some of the advanced techniques with light and scheduling and have been wondering what is valid and what is not. Thanks for the clarity on the 36 our darkness issue.


I would not go down in amount of light for end of flower tho, I might try adding a light that could give better trichome finish. Adding some UVb (use great caution with this) or look to change the spectrum for the last week or two, using a bulb that is in the 10,000k range. Something like a PSMH, or CMH or even a MH in that range. It makes a big difference with getting trichs to turn amber.:D
OM

PSMH - is that a conversion bulb? If I could run a CMH I definitely would but unfortunately it requires a coil/magnetic ballast or a rarefied electronic ballast neither of which are in my arsenal.