Growing with an 18 hour day/night cycle

eza82

Well-Known Member
This will help!



Periods of Activity (Times during which Flowers are Open) in a Number of Intrinsic Flowering Plants (according to E. BÜNNING, 1953)
http://www.biologie.uni-hamburg.de/b-online/e32/32h.htm

Reading this.......most flowering plants in this example only require a 6 hr OPENING period.... ranging from 6am - 8pm (except the night examples) but still need a 24 to 26hr total cycle period???

Why are the BIG dutch hydro farms on 12/12 ?
Conflicting for me.....
I thought a hormone called "florigen" controls budding and flowering. Long day plants require about 14 to 18 hours of light to produce just the right amount of florigen to flower and reproduce. Short day plants require about 10-13 hours of light. If short day plants are exposed to too many hours of light, florigen can be destroyed, preventing blooming..... too little it wont produce enough to max yield....

BUT IN THEORY I SUPPOSE a 6hr on 12 hr off could work ?? for bud
Maybey 10/12 or a 22hr day ?? for bud & trying to max hormone production.....
 

SlowToker

Well-Known Member
Seems to me the 18 hour day, true or not would be very hard on a person as you would have to live your life around an 18 hour day. This if nothing else is a good reason to not try it.

If one could I'd say it would be worth trying just to see if you could trick mother nature!

Peace
 

Hobbes

Well-Known Member
You're right about the 18 hour day, it's a deal breaker for a personal grower. Going into my garden during the routine of my day is relaxing, one of my moments of peace.

I too am curious why commercial growers don't use this, if it works. I'll search the web for reports of people growing on an 18 hour day.

While we could argue that plants evolved with a 24 hour day and therefore should be grown that way; we could also argue that mother nature often puts some extra capacity in her organism ... organisms ... organismes, so a flowering plant may only need 6 hours to gather the energy needed if the sun is overhead, no clouds, no shade. The extra 6 hours in the 12 in case it's a cloudy day, in the shade of a tree for hours a day, etc.

.

bongsmilie
 

Hobbes

Well-Known Member
"Its proven, less light = less bud."

Agreed. This is offset by adding CO2.

"NOTE: To achieve these incredible growth rates it is important to provide maximum light intensities and CO2 enriched conditions. The recommended lighting is 600W per square metre."

"The reason we grow with 18-6 (some 24-0) and 12-12 is because its what ACTUALLY IS PROVEN TO WORK. If there was a better way, thats the way it would be done"


I think the system is too much work (scheduling) for most personal growers, and adding in CO2 comes behind a new electronic ballast or some other piece of equipment in the garden, though perhaps it shouldn't.

For Commercial growers most would presumably be using CO2 already, so they can't offset the loss in yield by supplementing with CO2. So they do extra grows, extra work, on an 18 hour day for no gain in yearly yield.

.

bongsmilie
 

SlowToker

Well-Known Member
Hey man, Google shows more hits on RIU regarding 18 hour grows than amy other site I can find. This should tell us something!

Peace
 

orgnlmrwiggles

Well-Known Member
**everytime i say HID, i am refering to a metal halide**

sounds like a good concept i was thinking about something along the lines of changing times slightly to test different things.

i honestly dont think this will work in shortening the flowering time tho. Im pretty if you did it this way, it might be a good experiment, i dont think it will shorten flowering time whatsoever though, if anything, maybe increase yield since your giving it light exactly how she can feed on it.

My theory :

ok so if you think about from about march 20th til september 22, (in the northern hemisphere) days are longer by a small margine maybe a couple minutes. and this would be the ideal time to flower outdoors (outdoors = more yield) eventually if you add it up, doing indoor 12/12 is always the same, outside, flowering is more like, the month, May would be like 12.1hours of light/11.9 hours of dark. July would be12.2hours of light/11.8 hours of dark and august would right about 12.1hours of light/11.9 hours of dark such as may. so technically your lighting cycle is everychanging. also, the intensity of the sun in the first couple hours and last couple hours of the day would be less then what they would be during the day, by comparison(example on 4 plants), running 400watt HID 2 hours, then running a 400watt HPS for 4 hour and turning off the HID, then run the HID for 2 hours and turning off the HPS. then giving the plant 8 hours of darkness.

maybe also, at the beginning of flowering, if using the HID>HPS>HID>Darkness theory, run hid for 2.1hours>hps 4.1 hours>hid 2.1 hours, darkness 11.7 hours. for the first 2 weeks, the next 4 weeks do, hid 2 hours>hps 4.5 hours>hid 2 hours/darkness 11.5 hours. and the final 2 weeks go back to run hid for 2.1hours>hps 4.1 hours>hid 2.1 hours, darkness 11.7 hours, or just 12/12 with hps and darkness.

also i believe kelvin somewhat changes throughout the year, (spring, summer, fall, winter) so i somewhat based the HID/HPS changes off that.



As a consequence, for half a year (from around March 20 to around September 22) the northern hemisphere tips toward the Sun, with the maximum around June 21, while for the other half year the southern hemisphere has this honour, with the maximum around December 21.
 

orgnlmrwiggles

Well-Known Member
i would think working around an 18 hours day would be way easier. instead of 1 time a day, you have two seperate times a day in which you could go in to check your plants.
 

murtymaker

Well-Known Member
Could I use this theory to make a 6on/18off cycle? It would help very much in my daily routine... any thoughts on that?
 

Mr.Funk

Well-Known Member
Hey whats up? this would be my first time growing and i was wondering if the grow tents are pretty good? If i chose to get one what kind of lighting do you think i should use ? Thanks Peace
 
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