Experimenting with Light/Dark Hours

[Frazz]

hey folks Im not knocking this new 12-1 lighting regime here ..ok

 

just posting a couple of observations ive made over the years ive been growing .. so make what you will of the following

 

often i grow outdoors in summer so i start the plants off indoors under hps

13 hours light(gradually increasing over time), 11 hrs dark, so that when i put the plants out they are roughly on the same timeline as the Sun and dont go straight to flower

 

when i grow indoors exclusively i run 18 to 20 hours light, 6-4 hours dark (average)

 

now for me it is as plain as the nose on ya face that the 18/6 light plants outstrip the growth of the 13 hr light plants by a phenomenal amount.

 

Broad wide leaves on plants ... ok, the strain has strong Indica dominant genes,

whereas Sativa strains have narrow thin leaves

Why is this so? .. they are both from the Cannabis family genus, but grow at different latitudes

 

Sativa strains grow wild in the tropics close to the equator where sunlight hits the Earth's surface almost at a right angle, so the light is more intense than anywhere else, it travels a shorter distance through the atmosphere before reaching the ground, so less is absorbed by atmospheric gases and aerosols

 

Indica plants grow wild at latitudes further away from the equator where sunlight hits the surface at progressively more oblique angles due to the spherical shape of the Earth, so that the same amount of sunlight covers a larger area at higher latitudes and has to travel thru more atmosphere therefore the sunlight reaching the ground is less intense than the Equatorial regions

 

Could this be Cannabis' way of compensating the two different genus Sativa (narrow leaves) and Indica (broad leaves) so they both receive an adequate amount of sunlight/energy to carry out the Photosynthesis necessary to achieve rapid healthy growth?

 

To carry this theory even further to 12-1 Lighting regime of growing is it possible the broad wide leaves produced are compensating for inadequate periods of light ?

 

or are these in fact just thoughts from a perpetually stoned mind

 

[buzzo]

Could be onto something there Frazz. As for Auto's I'm finding 18/6 to be the ticket.

I find 20/4 when in flower is too much work for the plant and they tend to be more droopy leading into the on time.

Just thought I'd put my own observations for the Auto Growers.

 

Check out the Budwider Auto at 7 weeks from seed at 18/6

[brick]

good post Frazz. logical.

[wietlover]

Yup +1..makes total sense!!

[El Gato]

yeah good obs frazz. I thought thought the leaf difference between indica and sativa was due to water retention and humidity.

[The Hash Nibbler]

Heya Frazz, that light intensity affecting leaves structure works for me Outside in nature climate also affects leaf size. Plants in warmer enviroments genetically over time produce thinner leaves to reduce evaporation from their surface area.

Some will even lose their serated edge in these climates..... as in the case of Mongy weed. Most native Australian plants dont have serrated leaves for this reason. lt aids in lessening moisture loss.

Wider Indice type plant leaves are usually found in cooler climates where moisture loss is not a concern.

 

To be honest I'd like to see 12/1 work, everyoone woould like to save a bit of moolla. And if it was even in the same ball park, I would use it.

At the start aI was annoyed, not with the theory, every theory must be tested, but with the way it was being spruiked as the second coming of Geebus by people who hadn't used it. A lot of newbs here dont have a lot of money and are impressionable and I dont think that type of approach helped anyone. They need to get the basics down pat first and then experiment later once they understand the basic growing principals. Its hard enuff to get started.

So if I was overly passionate on the subject, sorry.

Im not against change or experimentation in fact I embrace it, its how we better our growing.

Over the years I have seen theories come and theories go.... The best advice I can give to anyone starting out is......

 

Stick with the way the growers who have been doing it forever use. At some stage everyone of these growers has experimented and questioned their technique , maybe even changed the way they grow.......more than a few times. Listen and learn and for gods sake, use cannaversity. People went to a lot of trouble to make it easier for you and all you gotta do is read it. Pretty easy.

 

I,m no flat earther... I'mm a reallist. Peace. Gh72

[MongyMan]

To be honest I'd like to see 12/1 work, everyoone woould like to save a bit of moolla. And if it was even in the same ball park, I would use it.

At the start aI was annoyed, not with the theory, every theory must be tested, but with the way it was being spruiked as the second coming of Geebus by people who hadn't used it.

 

+1 That's been my thoughts exactly GH

 

 

Peace Mongyman

[El Gato]

I agree with GH here. I have fad a few outdoorsies without great success. That came down to a number of things. As soon as i went indoors I couldnt believe how easy it was, but what astonished me was the growth rate compared to outdoors. Maybe my outdoorsies were real crap, I dont know. Now inside i take it more seriousely and buy good nutes and media. Goods lights, great airflow. But to someone who had a few outside and new inside i am so so suprised. I am fairly used to it now but it still spins me out a bit.

 

So maybe your not seeing great growth due to the lighting regiem. It could be the conditions and the relitive newbee status of the guys promoting this being suprised. Also from the various pics I have seen I am sceptical that they are growing quicker. I wish I knew how old my plants are now. I have some seeds popping up at the moment so we will see. Would like to do a diary but cant commit and pc is rooted so cant upload photos yet.

[Delta 9]

I'm going to be a trailblazer. Veg for half under 12-1, then half under 18-6. Stress much?

[Delta 9]

Ed Rosenthals take on the 12-1 light method...

 

http://edrosenthal.com/2011/04/ask-ed-marijuana-grow-tip-9-12-1-light-cycle-theory.html

 

A theory is circulating Facebook about the 12-1 light cycle as an energy-saving technique that facilitates excelerated growth during the vegetative stage of growth. Personal attacks are irrelevant, here is the scoop behind 12-1:

 

Plant growth is based on photosynthesis, which produces sugar.

 

When sugar is combined with Phosphorus (P) and Potassium (K) it forms amino acids, which are the building blocks of tissue and plant growth.

 

The more light plant’s receive the more building block amino acids they produce, aka growth.

 

They certainly grow well under the 12-1 light cycle as being advertised, but only simply because they are getting more light. Although it saves energy, energy equals growth.

 

And his take on 24-0 for veg

http://www.cannabisculture.com/v2/content/2011/06/08/Ask-Ed (Halfway down the page)

 

Marijuana grows fastest under continuous lighting. In experiments performed in the 1980’s plants under continuous light during vegetative had a yield increase of 15-24%. If you are seeking the fastest growth possible during this period, keep the lights on 24 hours a day until the plants are forced to flower. The plants will grow well when they are given a dark period daily, however their growth rate will be slower. The lighting regimen is a choice for the grower to make.

 

Several grow book authors and most growers believe that marijuana needs a “rest period†of darkness for best growth. This is based on misinterpretations of several pieces of information. Most green plants are classified as either C-3 or C-4, which represents the way carbon © is used during photosynthesis. C-4 plants, including many fast growing tropical plants, temporarily store carbon dioxide (CO2) over the dark period (night) to use for photosynthesis during the day. C-4 plants slow down photosynthesis once the stored CO2 is used up and they must gather CO2 from the air. That’s why trees often slow photosynthesis in mid-afternoon even though the sun still bright. At least one author stated that this applies to marijuana. It doesn’t.

 

C-3 plants, including marijuana and most vegetables, gather CO2 only during the light period when they are photosynthesizing. During the dark period these plants use only oxygen for their metabolic life processes, similar to animal respiration. They don’t take up CO2 then, nor do they use it. As soon and as long as the light is on, C-3 plants gather CO2 from the air and restart photosynthesis.

 

Marijuana and other C-3 plants also have the ability to use higher CO2 concentrations than the 400 parts per million (ppm) found in the air. If the light is bright enough and the plants have sufficient nutrients and water, plants respond to CO2 enrichment of up to 2,000 ppm by photosynthesizing faster and growing at an accelerated rate, resulting in higher yields. They can do this continuously, without a dark period throughout vegetative stage.

 

The dark reaction is a process of photosynthesis that takes place both in darkness and light. Briefly, the dark reaction uses ATP and NADPH, which are molecules that hold energy absorbed from light. The energy is used to break apart CO2 to its components, C and oxygen (O). The O2 is released as gas into the air in another reaction that takes place only under lit conditions. Because it’s called a dark reaction and can occur in the dark, some authors have written that darkness is needed for this process to take place. This is not so.

 

Another reason that some people think plants need a rest period is they anthropomorphize the needs of the plants. People need a rest, so plants must too. One well-known example of plants not needing a rest is Alaska, which is renowned for its giant vegetables. They are the result of continuous light in the early part of the summer. The growth factor deals with the equation that for indoor growers: light = growth. If the plants receive a brighter light or the light is on for a longer duration they grow faster than with a dimmer light or one of shorter duration. A plant under 18 hours of light will grow only three quarters as fast as one under continuous light.

 

There are many factors that growers may consider when deciding whether or not to light their garden continuously or with a break every day. These include the electric bill, convenience, and how fast the grower wants the plants to grow. The electric bill may be a factor due to finances or fear of a noticeably faster meter than the neighbors. It may not be convenient to have lights on at certain hours. If a grower is timing the plants to be a certain size at a certain date, s/he may not want the plants growing at full speed. Reducing the number of hours of light can be used to slow down the growth rate to control plant size.

 

Another reason to grow plants using a dark period is if they are to be subsequently placed outdoors. Some plant varieties, when grown under continuous light and then placed outdoors, especially in the lower two thirds of the U.S., are shocked into flowering by the change to only 14 to 16 hours of light even on summer’s longest day, June 22. Plants grown using a six-hour dark cycle don’t have as much of an adjustment to make and are less likely to exhibit photoperiod confusion.

 

Some varieties flower with as few as seven or eight hours of continuous darkness. That’s a light period of 16 or 17 hours. To keep the plants in vegetative growth, the longest continuous dark period the plants should receive is six hours.

 

Let’s say that for a certain set-up the plants need to grow half as fast as they would under continuous light to be the right size to place in the grow room. That calls for increasing the dark period to 12 hours. However, the plants would be forced to flower if they received an uninterrupted 12-hour dark cycle. Instead, split the dark periods into three or more periods of darkness interrupted by a light period. For instance, four hours on, four hours off, or one hour on, one hour off. The plants will never receive more than a few hours of uninterrupted darkness so they won’t flower.