An Experiment: LED and sexual determination

[gojo]

***NOte:
I started a thread in the outdoor sub- forum "Team Gojo 2008! (with LEDs and sexual differentiation!)" (https://www.cannabis-world.org/cw/showthread.php?t=4506) but it seemed like this sub-forum is a better place for the high-tech side of my current grow. In this thread it would be best if we talked about LEDs and sexual determination (under all it's guises). I thought the topics of LEDs/sex and outdoor growing would be too much for one thread...heck, LED and sex should be separate threads too but I don't have that much free time...soon come I will though!


A special topic of note is "feminized seeds". These seeds have been produced in such a manner (i.e. chromosome) that they are inclined to be female but they are not fixed as female. A feminized seed can be fixed as a male during sexual differentiation. IMVHO, "feminized seeds" are a waste. If you follow proper sprouting guidelines you should get over 75% female seeds from a standard pack. So, you can buy two packs of standard seeds for $150 (20 seeds) and get over 15 females OR you can buy one pack of fem seeds for $150 (10 seeds) and only get up to 10 females (most of which will have slight genetic deformities due to how fem seeds are produced...yuck!)


:joint3:


LED:
A really quick and dirty intro:
I'm doing a little experiment with a custom made LED. The problem with most LED is they are too weak, especially the blue ones. You want at least 10watts per LED and you NEED to light from above and below to maximize LED light usage and depth penetration for flowering.

I've been in discussion with a person who makes custom LED's for plants and he's been helping me with the math that will provide a REAL guideline for how much watts/diodes of LED you'll need to replace an HID. The math is really heavy and it's still not right, but after more thought and work I think I should be able to post a guide based on REAL data, not some half-baked, commercial advertised "UFO" bullshi*!




The test subjects...mwahahaha!!! :stir:

http://img210.imageshack.us/img210/4989/bothlights1fd5.th.jpg (http://img210.imageshack.us/my.php?image=bothlights1fd5.jpg)



Control samples:4' floro w/(2)4' "cool white" 40watt bulbs
http://img177.imageshack.us/img177/4703/flordown3sg0.th.jpg (http://img177.imageshack.us/my.php?image=flordown3sg0.jpg)



more floro:
http://img297.imageshack.us/img297/3537/florup4nb1.th.jpg (http://img297.imageshack.us/my.php?image=florup4nb1.jpg)



Test samples:180 diode, 10watt, blue LED @ 490nm
http://img205.imageshack.us/img205/9067/led2in3.th.jpg (http://img205.imageshack.us/my.php?image=led2in3.jpg)



Gotta love the blue!
http://img205.imageshack.us/img205/2714/ledthree5mt1.th.jpg (http://img205.imageshack.us/my.php?image=ledthree5mt1.jpg)



Small and powerful:
http://img205.imageshack.us/img205/8779/leddown6ou3.th.jpg (http://img205.imageshack.us/my.php?image=leddown6ou3.jpg)


My shiny toy!
http://img186.imageshack.us/img186/2035/ledforward7fe5.th.jpg (http://img186.imageshack.us/my.php?image=ledforward7fe5.jpg)



http://img181.imageshack.us/img181/4993/led8td1.th.jpg (http://img181.imageshack.us/my.php?image=led8td1.jpg)




My Experiment:

Background:
Sexual expression of Cannabis L. Sativa is not fixed until the point of sexual differentiation[2]. Sexual differentiation happens a few weeks after sprouting[3]. Cannabis L. Sativa can be guided towards one sex or the other during that time period through manipulation of the environment[4]. In general, to encourage female sexual expression you want to reduce stress and discourage high intensity growth environments.


Theory:
I believe it's possible to reduce plant stress through light wavelength manipulation. I am going to use a blue LED which creates little stress and emits the perfect level of blue wavelength for plant growth (PPF) at 490nm.

-->Problem with red photons:
Red photons (670-700nm) operate at a much higher fluctuation rate, that is, they move more quickly and are more "energetic" then blue photons. Because red photons are more energetic and more readily absorbed they increase the plants metabolism to a higher rate which increases stress overall. Red photons will heat up the leaf's inner fluid more quickly than blue photons and red photons are more "intense" on the leaf then blue photons.

Hypothesis:
By using blue LEDs with the PPF "sweet spot" of 480-490nm from sprouting until sexual differentiation (about 0-4 weeks) the sexual expression of Cannabis L. Sativa will show a greater proportion of females to males (when all other environmental factors are met).

Materials:
-(1)180 diode, 10watt blue LED @ 490nm
-(1)4' floro with (2)4' "cool white" 40watt bulbs

Procedure:
1. Environment must meet rules[5] for both test sample and control sample. Both test and control samples are grown in same room next to each other and they both get the same exact treatment to insure fewer extraneous variables.

2. Test Sample: (3) Timebomb seeds are sprouted under a new 180 diode, 10watt blue LED at 490nm.

3. Control Sample: (3) Timebomb seeds are sprouted under a new 4' floro hood with (2)4' "cool white" 40watt bulbs

4. The experiment will continue until the 5th node leaf set begins to appear...until sexual differentiation has definitely been fixed.



Sexual determination and differentiation:
A really quick and dirty intro
I'm sprouting (3) Timebombs under the LED to see if blue light has an effect on a seeds sexual expression at the time of sexual differentiation. I've found info on nearly all aspects of environmental effects on sexual determination except for data on wavelength and PPF/D. So I'm doing an ad-hock experiment with a custom 180 diode, 10watt blue LED (490nm). Blue LED's don't come in this size, only red's come this large, but you can get custom blue ones built for you.

An important scientific fact is that Cannabis L. Sativa (hemp) does not become female or male (expression) until the point when the 4th node's leaf set begins to appear (differentiation). I've been doing a TON of research on sexual determination, differentiation and expression of Cannabis L. Sativa. I've found a lot of scientific fact that disputes many of the long held beliefs in regard to cannabis and a seeds sex...namely that a seed is male or female before it sprouts...hog wash!

Please note that I am not copying the info posted by Henk from Dutch Passion, though he got most of his data from the same place I did. Except I've got more accurate and recent data, especially regarding non-usage of cytokinins. But, due to a crashed USB drive I lost a lot of the links to journals, my notes, etc, :bang: :Noooo:

There are many factors which effect sexual determination in Cannabis L. Sativa but the most important one to remember is that sex is fixed when the 4th node's leaf set is appearing. Here's a good set of easy rules:

From when you sprout until when the 5th node's leaf set starts to appear:
Low stress, lower level of nutrients, lower heat, higher humidity, less hours of light, NO CYTOKININS! (no seaweed), lower light intensity, soil/media on the moist side.

[1] Sexual Determination:
The biological system that determines the development of sexual characteristics.

[2] Sexual Differentiation:
The process of development of the differences between males and females from an undifferentiated zygote (fertilized egg).

[3] http://www.springerlink.com/content/t491042240h422v8
(NOTE: This is only one study but I have found two others which came to the same exact conclusion)
Microscopic analysis of male and female apices revealed that their reproductive commitment may occur as soon as the leaves of the fourth node emerge; the genetic expression of male and female apices at this stage has been compared by cDNA-AFLP. A rapid method for the early sex discrimination has been developed, based on the PCR amplification of a male-specific SCAR marker directly from a tissue fragment.

[4] http://en.wikipedia.org/wiki/Cannabis#Mechanisms_of_sex_determination

[5] Basic Rules: Low stress, lower level of nutrients, lower heat, higher humidity, less hours of light, NO CYTOKININS! (no seaweed), lower light intensity, soil/media on the moist side.

[islandgrow]

So basically your trying to get more females by using the basic rules below?
Sorry gojo I can't read it all right now, but that sounds really groovy. I really wanna know how it turns out :popcorn:

[gojo]

Hey IG,

Yea, those basic rules I posted will help female expression. They have been proven by scientific trials at major Universities in the US and especially in Inda, Pakastan, etc.

I am also trying to see if I can collect any useful data on how blue light effects sex determination. I believe blue light will help female expression to a large degree.

later!

[purplehaze2]

yea! I bought 2 ufo's for 1300$ and they suck . maybe I can use them
on my seeds.

[gojo]

yea! I bought 2 ufo's for 1300$

Ouch!!! Sorry 'bout that! My 180 diode blue cost me $150.00 and it's nearly half as powerfull as one UFO in terms of light emitted (not in watts). How many diodes does one UFO have?

With todays LED technology and prices doing a grow with only LED's to replace a 600watt HPS will cost you about $1,000-1,500 but that means only using 180 diode lights. LED's can be used to grow great cannabis but it's not for the faint of heart or wallet (as you've seen!)...I've yet to see a working system/array of LED that can replace a 600watt HPS.

I've got a good set of plans for a usable LED array to replace a 600watt but it's still rough and I need to understand the math better first. Good thing is anyone can build there own. What I need is to do is build the array, buy and wire the LEDs and have a light "rotator" built (something my stoned mind came up with). I should have a working prototype by this fall-winter (October-December), I'm just too busy to do it now. I'll write a thread as it will be reproducible in a do-it-yourself manner.

maybe I can use them on my seeds.

You can but not in the way I am (for females) because your UFO's have red LEDs. You could also use them for clones or to light the bottom of your canopy as an adjunct to a regular HID...just point them up towards the under-canopy. From what I see a design flaw for those UFOs is they are WAYYY to heavy in red photons (PPF); they are not even close to balanced red/blue.


-Can you return them?
-If you can't return them you could sell them on Ebay or similar sites and get your money back or even make a little!

[outdoordreams]

A friend of mine is using LED lighting for his grow. Horrible results. Could have been the grower, could have been the lights. I wasnt impressed with the lighting system at all. The cost was outragous, and the system only has 2inch diameter circles filled with LEDs, and then each circle is spaced about 1-2 inches apart. They could have fit way more LED lights in the 4x8 area.

But if we can use it for seedlings, then it wont be a total lose.

IM very happy to see you are testing this out.
Im really excited to see your results. Best of luck to you.

[gojo]

Hey ODD,

Sorry to hear about your experience, almost all LED's are snake oil right now...especially any LED "grow system", total crap!!!

The biggest problem with LED is people are thinking 2 dimensionally, when they should be thinking 3 dimensionally. The LED should hung above the canopy pointing down, below the canopy pointing up and within the canopy pointing down or sideways.

LEDs have crappy depth penetration and when for-profit numb-skulls make a super duper LED grow system that pretends to be a horizontal HID it makes me laugh at them :point: and have empathy for the customers who didn't know any better and would like to :blast: the LED manufactures.

Another issue I have with LEDs is there shape, whats up with the roundness? How retarded is that? I want a square LED so can make a square or rectangle rack without space between the LEDS. Then a forward/back type of light mover would be VERY useful, it could even be made to work with my plans for a light-rotator (see below).

But if we can use it for seedlings, then it wont be a total lose.

True, it should work very well. Just make sure to keep it very close to the seedlings (2-3 inches). I think the depth penetration is much less than reported to be. I'll take some readings in a minute but I only have a basic light meter; not a photon meter.

How far apart are you LEDs on the rack? You said they were the small 2" LEDs? What is that, 4 or 6watts each? How many diodes in each LED (30-90 I think)?

You could also take apart your LED rack and use them to supplement your HID. You can use individual LEDs in less well lit areas of your canopy by hanging them above those spots. Or you could hang some individual LEDs within your canopy, or hang/set them below your canopy pointing upwards. It's best to use blue color when "in-lighting" or "under-lighting" your canopy, plants absorb more blue in shaded leafs.

BTW, I just made up the terms "in-lighting" and "under-lighting" because as far as I know there are no terms to describe canopy placement of LEDs 3 dimensionally (please let me know if I'm wrong).

If your going to use them for seeds I would wait until I have tested it if your trying to use only blues (I think I've found a problem).

If you want to use red and blue I would take each LED off of the rack (or whatever it's attached to) and make my own rack. I would space them very close together. Make a whole row of blue and then a whole row of red and a whole row of blue and so on, make sure to end with a row of color opposite from the first row. LED light is VERY focused so to prevent any one seedling from getting say all red or all blue you need to some how rotate the color of light. Either by moving the plants, say on a huge ass "Lazy Susan" or move the LEDs. IMHO the only choice is moving the LEDs, so I suggest once a day rotate your new rack 180 degrees clock-wise and the next day rotate 180 degrees counter clock-wise and so on. This way the color of light will change every day giving an even mix to the seedlings...both red and blue are nearly equally important IMVHO. I've researched PPF a lot and IMO it's like nutrients, a plant will take what it needs in terms of red and blue photons. To me a perfect mix is 50/50 and let the plant decide! :old:

I have thought up an automated system where an actuator (or something) rotates 180 degrees clockwise and then counter clockwise. It can be attached above (to a ceiling for example) and from below for the LED rack; kind of like a "sun-twist". I need to talk to a machinist or mechanical engineer; time to call the local University again! I'm not sure if it's best to make it constantly rotating or set it on a cyclic timer every X minutes (any input?)



IM very happy to see you are testing this out.
Im really excited to see your results. Best of luck to you.

Thanks, me too.

[gojo]

Hey all,

It's been 7 days since I buried/germinated the seeds and it looks like just using one color will not work. I thought there may be issues but I was hoping for none as the time under the blue would be so short. Under the blue LED my seedlings streached as they do if a floro is too far away.


Results:

1. I started the seedlings about 3-4 inches from the LED.

2. After they sprouted I kept them at this distance for about 48 hours and they began to stretch noticeably when all other TBs under the floro's where developing their first set of true leafs.

3. After another 24 hours I moved the seedlings to within one inch of the LED.

4. Another day later the TB under the LEDs continued to stretch touching the light. The first set of true leaves and the immature leafs (codalidens sp?) were not developing. At this point the tallest of the TB under the LED was actually touching the LED and continued to stretch by bending over.


Un-scientific-Conclusion

It seems like it's not the distance to the plant that is causing the stretch and non-leaf growth. I saw the same stretch whether the plant was 4 inches away or touching the LED.

I assume the problem is lack of red photons and not lack of LED power in regards to watts or diodes...I'd rather use a PPFD meter but they are $10,000 for a good one.

The plants under the floros are growing very well and not stretching at all. If they grow well under the low light of floros they should grow fine under my LED if power or intensity was the problem.

I have stopped using the blue LED and I moved the seedlings under the floro. I didn't see any reason to continue this experiment because the plants were obviously not happy and unhappiness will encourage males.


My take on LEDs:

I haven't tested LEDs enough to have an opinion on their viability as the sole source of light. I want to do some tests with blue and red LEDs to find the real world depth penetration and how far they should be hung from canopy. So I'm gonna order some 180 diode red LEDs (9watts) and do some tests.

What I want in terms of a LED is a square LED with an equal amount of red and blue diodes placed so they mix well...red-blue-red-blue-red-blue...This way all both colors are present and hit each plant. There would be no need for a light-rotator or a mover because they color mix would be well balanced over the whole canopy.


Close to the LEDs!!!
(seedling on left was floro, seedling on right was LED)

http://img215.imageshack.us/img215/8900/ltbnrtbyyx8.th.jpg (http://img215.imageshack.us/my.php?image=ltbnrtbyyx8.jpg)


TB germinated under a floro:
(All the plants under floro look like this, nice and stout):

http://img215.imageshack.us/img215/9844/tbnoledqn5.th.jpg (http://img215.imageshack.us/my.php?image=tbnoledqn5.jpg)


TB germinated under a LED:
(All 3 TBs were tall but this was the tallest, not by much!)

http://img146.imageshack.us/img146/2121/tbwithledll5.th.jpg (http://img146.imageshack.us/my.php?image=tbwithledll5.jpg)



...to be continued!