24/0 vs. 18/6

[BabyHughie]

i understand that plants need rest, but i've never had my plants droop simply because of a 24/0 schedule. why would this cause a plant to droop?

On the flipside of that, plants DO droop right before lights out. Almost as though they are tired from the long day of growing and know its time for a nap. And they definately know when the lights are about to go off, AND on.

Im not gonna touch why 18/6 is better growth wise (Verite has that on lock) but Ive ran both and haven't noticed a difference either way really. I do 18/6 because it saves a good bit of $$$ and it gets so damn hot during the day that its almost necessary.

 

[Guest]

Mama don't take my phytochrom's away

 

[Verite]

Mama don't take my phytochrom's away

Oooooeeeeeooooo!!

 

[Brastaman]

I've done 24/0 and 18/6 and 16/4 in my veggie room.
In soil i've notice 24/0 grows the quickest.
In hydro there was not much difference between 18/6 and 16/4.
These experiments were with MH and/or Flouro's.

I say weigh the marginal cost to the marginal benefit. Up to you. It all works well.

Whichever you choose stick with it. I've seen growers switch times during veggie stage and plants began to flower! Ooops!

As long as the plant is being given the proper diet to succeed in the light, it does not need to necessarily sleep. I have not come across a strain that completely dies in the vegetation state from 24/0 light scheduling.

Hey Verite,
the phytochrome system according to your link, is a light detecting chemical that aids in stuff like germination, flowering and photosynthesis. Since phytochrome is light detecting there is no reason why 24/0 light scheduling would affect a plants ability to detect light. The information did not include how this pigment found in plants is developed in the darkness. But... since phytochrome is light detecting and aids in flowering, then if the phytochrome does not detect light it might begin to flower; especially if it has been exposed to 24/0 lighting previously.

 

[Guest]

wow i love this thread, i'm learning so much, this site is so informative. ya know in college i had to read sometimes 200+ pages a night, and afterwards i swore on my life i would never read a book again, i HATE reading, but i can never get enough of reading this site =c] (or any cannabis books)

 

[bbudd]

20/4

20/4

a VERY good grower in the UK did side by side comparisons and his best results and highest yeald was on 20/4 in veg
watch it if you switch from 24/7 tho-I had the males show in the first week-made it easy to sex but watch out for pollen
another funny thing is it seems the veg plants closest to the flower room seem to show more males

 

[Verite]

...
Hey Verite,
the phytochrome system according to your link, is a light detecting chemical that aids in stuff like germination, flowering and photosynthesis. Since phytochrome is light detecting there is no reason why 24/0 light scheduling would affect a plants ability to detect light. The information did not include how this pigment found in plants is developed in the darkness. But... since phytochrome is light detecting and aids in flowering, then if the phytochrome does not detect light it might begin to flower; especially if it has been exposed to 24/0 lighting previously.

You musta missed this part.

There are two isoforms of phytochrome - Pr and Pfr. The Pr isoform absorbs red light (at 660nm) while the Pfr isoform absorbs far-red light (at 730nm). Absorption of light causes phytochrome to inter-convert. Hence, red light makes Pfr, far-red light makes Pr.

Phytochrome is made by the plant in the Pr form. Since daylight contains a lot of red light, during the day phytochrome is mostly converted to the Pfr form. At night, phytochrome will slowly convert back to the Pr form. Treatment with far-red light will also convert Pfr back to Pr. Since plants use red light for photosynthesis, and reflect and transmit far-red light, the shade of other plants also can make Pfr into Pr, triggering a response called shade avoidance.

In most plants, a suitable concentration of Pfr stimulates or inhibits physiological processes, such as those mentioned in the above examples. Thus Pfr is considered the active form of the pigment.

http://en.wikipedia.org/wiki/Phytochrome

 

[Guest]

Cannabis plants are classified as ' short day plants ' that use the phytochrome system to sense day/night photoperiod. Plants use the dark cycle to convert phytochrome. Im pretty sure this process is desireable during the veg cycle too.

http://en.wikipedia.org/wiki/Short_day_plant
http://en.wikipedia.org/wiki/Phytochrome

Good example of how Eds advice should be taken with a grain of salt.
http://www.cannabisculture.com/articles/3127.html

A better start to understanding carbon fixation in plants.
http://en.wikipedia.org/wiki/Dark_reaction

maybe i missed it while reading this, but it never says exactly what the ideal amount of darkness is necessary...i've heard 4, and 6...

 

[SmokeAlot]

Hey, on my first grow i use a 24\0 (then 12\12) and evrything was just GREAT
but today its very hot so i was really wondrin about it.
i think that i will stick to my 24\0 and hope that all goes well, but this is just me

 

[minds_I]

Hello all,

Gee, I have been waiting for this old dog to be drug (pardon the pun) up again.

I have about seven days or so till I will be harvesting my last Afghani and I will need two replacements for them by then.

So, I have 7 seedlings that are 30 days old tonight. I set the lighting schedule on them from 18/6 to 16/8 to encourage preflowering four days ago. They are at 6-7 nodes and are getting close to being rootbound (clear 32 oz cups- I can see the roots) and ready for transplant.

My question is- do you think the shorter day may encourage preflowers in time to know which are which?

minds_I

 

[Verite]

Not as much as letting them get rootbound. 2 hrs shorter isnt going to reveal much.

 

[minds_I]

Damn, I was afraid of that.

Well, I do have thre option of just flipping them now to 12/12-6 days left or so-I could wait longer but that throws the grow schedule off.

But then again, I have been finding that the plants don't grow to my schedule anyway.

Its all good- I was trying to maintain a consistant perpetual grow-I need to work on that.

minds_I

 

[Brastaman]

hey verite,
I apologize I forget what I and I was rambling about. Stuck in high mode.

Uh... but from what I gather, the plants actually try and avoid the second isoform of phytochrome; Pr:
And the desirable isoform of phytochrome; Pfr: is the one that aids in photosynthesis.

 

[BLunTeD4LifE]

cannabis is a C4 plant

hmm... i read somthing by ed rosenthal and he says that cannabis is a C3 plant??

whats the deal?

whos right?

 

[Guest]

I thought it was a C3PO

 

[Guest]

lawlz

 

[clowntown]

!

 

[Guest]

Mama dont take my phytochrome away.

 

[Guest]

is it ok to go from 24/0 to 18/6 in the middle of veg? i dont want them to start flowering from the new dark period.

 

[Guest423]

depends on the strain but most won't....some super sensitive indicas might....some even flower under 24 after awhile!