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Daylight Mimicking

M

MichiSin

I was wondering if there were any grows or studies (spec here) where someone mimicked actual daylight hours to match up with either their environment or the environment where the genes came from.

I guess temp and humidity would be nice additions, you know to bring out those autumn colors.
Im very curious to know because a cycle of 12/12 every single day is odd to me and as we know dark hours are just as important as sunlight for the flowering girls.

It only reaches 12 hours in my area next month it was D13:14/N10:46 today and D13:17/N10:43 the day before. Thats a 3 minute decrease in daylength (nightlength is different and defined by the moons activity)

Any outdoor growers below 44° know when they usually start flowering in Michigan?
 
Dropped Cat

Dropped Cat

Six Gummi Bears and Some Scotch
Veteran
Some indoor growers use light angle to an advantage
for long flowering types.

Any growers in a perpetual style must submit to the
standard 11/13 or 12/12.

Higher elevations are a factor in the grow, too.

Me? I can only say the low temps will permit colorful
leaves.

Interested to see other more informed growers chime in.
 
B

Baron Greenback

DJ Short seems to recommend the 11/13 cycle for all strains. People also use 12.5/11.5.
The purer sativas seem to benefit from a slightly longer dark period but flowering times may also lengthen.
Many cleverer people than me will be able to tell you why :)
 
Phaeton

Phaeton

Speed of Dark
Veteran
When I looked into this there was a problem with twilight, the period right after sunset when the upper atmosphere is hit by the sun causing far red to bathe all the land underneath even though it is dark because the sun is past the horizon.
Tech with charts is here http://plantphys.info/plant_physiology/photoperiodism.shtml

Twilight is the trigger that tells the plant when it is night. Without the far red it takes two hours for the plant to neutralize the daylight and begin Florigen production. With the far red it takes ten minutes to begin production.
Stand alone Far Red LEDs are available from Philips lighting. These are produced for commercial greenhouses growing long night plants similar to marijuana.

Using these far red bulbs for 1/2 hour of twilight allows for the duplication of outdoor lighting times.
Presently I am growing a northern sativa at 14/10 using 52 watts (4 bulbs) of far red for 1/2 hour after lights out and another 1/2 hour before lights on.

This also allows for the occasional light leak without stress problems. When the plant gets the twilight signal it knows it is night and can take up to a full moon's worth of intensity without losing a step.

The rest of the lights are a mix of LED, CMH, and T5.
The UVB from the T5's will give a medium tan with four hours a day exposure, roughly half of a summer day's strength.
The LED's are the chlorophyll feed lights, all the red and blue they can eat.
The CMH are as close to the sun as can be bought and make sure nothing is missing, like both far and near infrared.

No other system in my area can match the garden clone against clone. The same as grown outdoors during a perfect summer with nary a single day of bad weather.
 

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huligun

huligun

Professor Organic Psychology
Veteran
I personally feel there are too many variables to try to duplicate to really match the environment of a landrace. If you go to tropical places you see the sun looks different. Colors for instance, not just time of light or when it really happens. The angle would matter as well. If you really want to duplicate the environment you may want to study and understand as many of these variables as possible. The atmospheric pressure or lack thereof from higher altitudes is a very tough one to duplicate.
 
Adze

Adze

Member
Sometime look at a spectrograph of the light emitted by any form of plasma lamp. Sun light has a nice smooth distribution of frequencies where all lamps emit spiky looking energy with gaps, not at all natural. I understand wanting to mimic daylight but these artificial lights are a rough place to start from.


 
Last edited:
Rusty Lugnuts

Rusty Lugnuts

Member
Phaeton said:
When I looked into this there was a problem with twilight, the period right after sunset when the upper atmosphere is hit by the sun causing far red to bathe all the land underneath even though it is dark because the sun is past the horizon.
Twilight is the trigger that tells the plant when it is night. Without the far red it takes two hours for the plant to neutralize the daylight and begin Florigen production. With the far red it takes ten minutes to begin production.
Stand alone Far Red LEDs are available from Philips lighting. These are produced for commercial greenhouses growing long night plants similar to marijuana.

Using these far red bulbs for 1/2 hour of twilight allows for the duplication of outdoor lighting times.
Presently I am growing a northern sativa at 14/10 using 52 watts (4 bulbs) of far red for 1/2 hour after lights out and another 1/2 hour before lights on.

This also allows for the occasional light leak without stress problems. When the plant gets the twilight signal it knows it is night and can take up to a full moon's worth of intensity without losing a step.
Click to expand...

This is amazing information. I've often wondered what role outdoor nighttime light played. Being able to work with more unstable genetics is huge, as well as also just being better at replicating nature is always nice. Have you noticed or would you theorize that yields would increase as well with the additional 2 hours of light?
 
Phaeton

Phaeton

Speed of Dark
Veteran
The original intent of the lights was to see if production would increase with the extra light. It works out to a full 7/24 worth of extra light in an 84 day bud cycle.

I got distracted when the sativa I was using produced no seeds at the six week point, something that could normally be counted on. I spent the next five harvests confirming the new stability of the plant and now am getting to the increased light/yield testing.

I do not like to have two changes going on at the same time, harder to separate cause and correlation with too many variables.
The plant is stable with known yields at this point so the new testing begins.

I will need another five harvests to insure consistency with whatever results are achieved. The perpetual puts out a plant every 25 days so an answer will be available in about four months.

Slow and steady, gardens do not take to rushing.
 
L

Lesnah

Active member
Phaeton said:
When I looked into this there was a problem with twilight, the period right after sunset when the upper atmosphere is hit by the sun causing far red to bathe all the land underneath even though it is dark because the sun is past the horizon.
Tech with charts is here http://plantphys.info/plant_physiology/photoperiodism.shtml

Twilight is the trigger that tells the plant when it is night. Without the far red it takes two hours for the plant to neutralize the daylight and begin Florigen production. With the far red it takes ten minutes to begin production.
Stand alone Far Red LEDs are available from Philips lighting. These are produced for commercial greenhouses growing long night plants similar to marijuana.

Using these far red bulbs for 1/2 hour of twilight allows for the duplication of outdoor lighting times.
Presently I am growing a northern sativa at 14/10 using 52 watts (4 bulbs) of far red for 1/2 hour after lights out and another 1/2 hour before lights on.

This also allows for the occasional light leak without stress problems. When the plant gets the twilight signal it knows it is night and can take up to a full moon's worth of intensity without losing a step.

The rest of the lights are a mix of LED, CMH, and T5.
The UVB from the T5's will give a medium tan with four hours a day exposure, roughly half of a summer day's strength.
The LED's are the chlorophyll feed lights, all the red and blue they can eat.
The CMH are as close to the sun as can be bought and make sure nothing is missing, like both far and near infrared.

No other system in my area can match the garden clone against clone. The same as grown outdoors during a perfect summer with nary a single day of bad weather.
Click to expand...

I will try and mimick this, because I will be starting with a full blown f1 tropical Sativa. What does the "CMH" stand for? Some type of Metal Halide or Chameleon brand lights?
 
amanda88

amanda88

Well-known member
I wonder how plants get on then at the equator

where dawn and dusk are but a matter of seconds

not much red light then...?
 
Bubbleblower

Bubbleblower

Member
Exactly.
For daylight mimicking you'd need to know how long the twilight takes first and consider at every latitude the spectrum will be different in more than one way.

In general before sun comes up you'd need to start with diffused mainly red light from a wide angle and then make it more intense,
direct and blue and from a sharper angle untill noon and then vice versa untill after sunset.

It takes a little bit of design :biggrin:, but it is well worth it; yield will be much better, you will no longer have fluffy buds and the plants will branch out a lot more.
 
Phaeton

Phaeton

Speed of Dark
Veteran
Lesnah said:
What does the "CMH" stand for? Some type of Metal Halide or Chameleon brand lights?
Click to expand...
Ceramic Metal Halide.
It is an HID with solid full width red coming out with the rest of the light, reaching 93% Color Rendering Index, about as close to the sun as is possible to get on a working man's budget.
The ceramic part is the arc tube, the gas to make red is too corrosive to use quartz like all the other HIDs, a chemically resistant ceramic is used to lengthen the life.
This increases the price of the bulbs over that of regular HID.

I had a friend go to an equatorial country. He mentioned all the tiny pot plants they have there.
The plants at the equator go to bud as soon as they are old enough to do so. The 12/12 year around light is the same as giving seedlings 12/12 indoors, except better because they still get over ten minutes of twilight.
I live at 66 degrees north and twilight lasts for an hour or more depending on season. Auto flowers got their start about this latitude over in Russia and Siberia.
 
Rusty Lugnuts

Rusty Lugnuts

Member
Phaeton said:
The original intent of the lights was to see if production would increase with the extra light. It works out to a full 7/24 worth of extra light in an 84 day bud cycle.

I got distracted when the sativa I was using produced no seeds at the six week point, something that could normally be counted on. I spent the next five harvests confirming the new stability of the plant and now am getting to the increased light/yield testing.

I do not like to have two changes going on at the same time, harder to separate cause and correlation with too many variables.
The plant is stable with known yields at this point so the new testing begins.

I will need another five harvests to insure consistency with whatever results are achieved. The perpetual puts out a plant every 25 days so an answer will be available in about four months.

Slow and steady, gardens do not take to rushing.
Click to expand...

Sounds awesome, way to go about things the correct way, can't wait to hear the results. Wow, that's a ton of extra light you get per cycle, hopefully it will have a corresponding effect on yield. Lots of possibilities, already two huge potential benefits in production and stability. Interesting variables in different latitudes twilight lengths. I'm excited, again amazing work man
 
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