[Samson4]

Intro
I haven't heard or read much about this technique up until I stumbled across a couple old experiments. These experiments were conducted between 1930-50's while scientist where trying to discover what part of the plant is light sensitive and triggers flowering.

The Experiments
What the scientist did was take short day plants during their "veg" cycle. They would then isolate a leaf on the plant and shorten the day length of that leaf. They blocked the light by taping black construction paper to both sides of a single leave.

What they found
They found that they could induce flowering by blocking all but 8 hours of light from one leaf of the plant. This single leaf would produce the flowering hormone in a suficient amount to trigger flowering.

The Theoretical Application to Our Purpose
If the experiment holds true for cannabis it will allow 4 major advantages:
1. Long flowering sativas can now be grown further away from the equator than usual.
2. Flowering and vegetation can occur under the same light.
3. A plant can be flowered under (18/6, 20/4 etc..) hours of light increasing yield and possibly reducing stretch.
4. Ruderelis genetics don't have to be involved to harvest before August.

I have not used this technique; but, if anyone has our has knowledge on the subject please do so.

[Abja Roots]

Very Interesting. Will be checking in to see what more knowledgeable minds have to say on the subject.

If you have a link to the study in it's full detail, please post it up.

[FoCo(No.Co)]

Lots of growers on these boards have been doing this for a long time... you can cover the plants or just bring them inside at the same time everyday... or if you have lots of money to invest you could put a retractable cover on a timer and put it over your greenhouse.

[Samson4]

Not what I'm talking about here. I'm talking about covering just one leave, not the entire plant. Please reread my post.

Abja:
https://books.google.com/books?id=xYT...akhyan&f=false

One of the leading scientist was M. H. Chailakhyan.

[HighDesertJoe]

Very interesting
I'm going to start making
ONE LEAF BLACK OUT COZY'S

[Honkytonk]

Look up Phytochrome manipulation.

Covering 1 leaf won't work. Even covering a branch flowers only that branch, not the whole plant.

[Grizz]

not sure it works on mj. i saw a pic of a plant that was outside by a street light, half of the plant was in darkness for 12/12, the other half was under the street light, the half that was in the dark flowered and the other half dident.

[Samson4]

Phytochrome manipulation doesn't have merit here. Especially indoors if wavelengths stay constant.

Why do you say one branch will flower? If you have done/witnessed this process please post details. Otherwise your post is wasted space.

[Samson4]

Originally Posted by Grizz

not sure it works on mj. i saw a pic of a plant that was outside by a street light, half of the plant was in darkness for 12/12, the other half was under the street light, the half that was in the dark flowered and the other half dident.

I see. That's very interesting. In this case, each half is sending/receiving flowering hormones. I'm going to run an experiment on this during this growing season.

[smokefrogg]

i'm not a scientist, but i have seen outdoor plants where half of it is full on flowering and the other half is full on vegetating, the flowering side being in a spot getting shade throughout part of the day. this tells me that covering or shading 1 leaf isn't going to make much of an effect...it would be neat if it worked that way though