Cannabis, the effect from increasing photo-period by only 15 or 30 min.

True. I havent read that part I guess. My bad. If he said it I still believe the guy. Instead of running my thumbs ill go do some reading.

There is a now rare (seen more in the 70's than today) trait in some sativas that create early amber, it is not a sign of degrading, it is a translucent amber with a mirror like appearance that when it begins to degrade turns red then black. I was not not changing my light timing to make the leaves more narrow that just happens, I was looking for early amber and I found it, IOW it worked, but was not just light timing I also needed UVB and sulfur.

I have brought it out in a Pineapple Express and Durban Poison so far and I have bred several strains that do it. My CTF (Colorado Thunderfuck) shows 50% amber in week 5 and finished with 90% amber and has zero couchlock, rather it is a very up energetic sativa high with no ceiling and no tolerance issues that tested at 25% THC

I do have lots of pics if needed

Hey beta I keep looking at that webpagr and fail to see any talk of leaves changing narrow to broad or vice versa. Yes it says indica leaf and sativa leaf and shows a picture. Not indicating that it changed rather indicating what each look like for a complete noob to know whats what. Not even gonna rwad that pdf download. Tried but not my thing.... any page in particular that talks about this?

Nope, you won't find claims specific to leaves there, nor claims specific to any traits, which is why I wrote he's too ambiguous.

However, knowing he considers NL and WL to be characteristics of sativa and indica, and he made a point to show a few pictures of leaves, I think it's pretty clear leaf morphology is a way he thinks he tells between photoperiod treatments (changes in duration).

And besides, this isn't even about leaves specifically, it's about his claim which seems to be the environmental factor of photoperiod, when changed by an hour or so, will affect progeny from seed. The specific changes he keeps referring to are not defined as far as I can tell.

It's true that environmental factors can affect progeny*, such as extreme stress like drought, but I doubt changing the photoperiod by an hour has a similar effect that isn't stress induced. And I'm even more doubtful when the claim is made the changes are easily noticed with the naked eye.

* http://www.ncbi.nlm.nih.gov/pubmed/21236268

That's the last I'll write about DJ in this thread as it seems we're going off topic.

Ok sorry did t mean to come off assholish. U may very well be right.

You didn't come across that way at all. I just think all this talk about DJ is getting the thread off topic. But it's not my thread, so I'll just shutup

Since the topic is about changing photo period id say u are on topic. Dj doesn't say the photoperiod difference changes genotype, he says it can change phenotype.

I think ur reading too deep and coming up with ur own conclusions of what he means instead of just taking it for what it is. Some physical differences can be seen from doing this, that's what I get from what he wrote.

And when I first went to 11on 13 off I noticed that the bud structure of a clone ive been running for about 10 years change its formation. From having a more block like cola formation to a more spear like structure.

Hey miraclemed which did you prefer? In terms of the bud. Did it alter the finished high as well? Which yielded more and which finished faster? Thx

sourpuss said:

Hey miraclemed which did you prefer? In terms of the bud. Did it alter the finished high as well? Which yielded more and which finished faster? Thx

Click to expand...

I had my record yield the first time I changed, but that is do to dialing the room more than the photoperiod change. Went from a 12.5oz plant with 300w to a 15.5oz plant with the same 300w.

It finished in the ballpark of the same time 70 days when I normally took it 73 to 75. so a little faster.

The finished effect is where im still studying. Its harder to measure but I would say it moved toward more a sativa effect of being slightly more up high than couch stone. But then I did take it a little bit earlier but it looked just as ripe? so more experimenting to be done.

But I will say it was definitive enough that I changed all my flower to 11 on 13 off.

Next I would like to experiment with going 13 on 11 off the last 2 weeks of flower. I read tom hill write about it adding a few extra days to the flower cycle but also added a noticeable gain in yield and tightness of bud structure!

Miraculous Meds said:

Went from a 12.5oz plant to a 15.5oz plant.

Click to expand...

Miraculous Meds said:

a little faster.

Click to expand...

This is very simular to what I found (in a side by side using 10-7-1-6 vs 11-6-1-6). It seems the more space the plants have the bigger the differences get. I am not sure if this lighting schedule would work with all plants as there are only 10 hours dark, but it has worked with everything I've grown since 2009.


Where are these

Beta Test Team said:

horse pucky

Click to expand...

claims, has anybody found them yet?


I did find this quote:

"It is my belief that this (12/12) light cycle strongly influences for Indica phenotypic expression"

DJ doesn't claim anything here, but I will; the light WILL influence the shape of the leaves.
The reason is simple; cannabis uses different strategies in different scenarios's and the shape of the leave is an integral part of that strategy.

Miraculous Meds said:

Since the topic is about changing photo period id say u are on topic. Dj doesn't say the photoperiod difference changes genotype, he says it can change phenotype.

Click to expand...

You can't change phenotype without changing genotype in his context...

And he's talking about *breeding* not what happens for a single plant.

And I still think DJ's claims are off-topic.

Miraculous Meds said:

I think ur reading too deep and coming up with ur own conclusions of what he means instead of just taking it for what it is. Some physical differences can be seen from doing this, that's what I get from what he wrote.

And when I first went to 11on 13 off I noticed that the bud structure of a clone ive been running for about 10 years change its formation. From having a more block like cola formation to a more spear like structure.

Click to expand...

No one is claiming, least of all me, that it doesn't affect morphology. BUT, that's not the same as what DJ is claiming. And again, he's talking about transgenerational effects...

Using less than 12 hours has little benefit when it comes to yield and secondary metabolites (unless radiation intensity is increased). Shorter days = less photons = less productive plants.

Beta Test Team said:

I post science, everyone posts speculation and guesses based not on data but the naked eye or smoke tests (never legit methods of measurement), and I'm the one who's questionable; okay. How many of you posting have read the thesis I linked to, especially the people using less than 12 hours?

Using less than 12 hours has little benefit when it comes to yield and secondary metabolites (unless radiation intensity is increased). Shorter days = less photons = less productive plants.

Click to expand...

I have read that study and a few more from GW Pharma who uses mercury vapor lights in their grow area, which is huge lol

I try to take government sanctioned research with a grain of salt much like the UN study that says 10/14 is detrimental to THC content

That study was not in their greenhouse with respect to this thread (it was a small indoor area), it was under HPS (IIRC) and PPFD was pretty low, around 300 or 400 I think.

The photoperiod is only part of the story, if people don't account for irradiance by the day (which is affected by irradiance per second and the photoperiod) then there's no way conclusion can be drawn from results.

My point is this topic is way more involved than just using a shorter or longer photoperiod by an hour and trying to make conclusions from the results without really studying the plant. Looking, smoking and weighing doesn't really count, as they're all affected by lots of other things that aren't accounted for by most growers (mostly notably, radiation per day).

Most science is funded (at least in part) by governments (local and country), and for drug studies often the research needs to be sanctioned (due to its illegal nature). I have yet to see a study not done by professionals on Cannabis that was worth a damn, I suspect because most people can't afford to spend $100K or $200K setting up a decent lab for plant science.

If you give the plant less hours of radiation per day, and don't increase the radiation to account for the loss from day reduction, then it's very logical that the plant will produce less cannabinoids due to the energy it takes to make them, terpenoids, etc.

If you can prove that using reduced photoperiod during flowering while not keeping PPFD and DLI at the same level as plants not under the treatment does not reduce secondaty metabolite production, you would be the first.

I'm a scientist and I understand that study very well. And sure it has flaws, such as using optical watts (aka PAR Watt) instead of true PAR (photons), and not accounting for substrate volume, etc., but it was more useful than anything else on that topic I've ever seen.

Using greater than 12 hour photoperiod per day for flowering can make a lot of sense (assuming PPFD is not too great), using less, without accounting for total daily radiation does not.

Beta Test Team said:

You can't change phenotype without changing genotype in his context...

Click to expand...

Are u sure about this statement.

Then how does my friend grow a physically different looking plant and end product from the same clone as mine?

I thought that proved phenotype differences of the same genotype?

Yes, I am. Though if someone can prove me wrong with facts, please do.

In DJ's claims, what he's saying (or appears to be saying) is the effect from his photoperiod changes the seed plants' phenotype (which can't happen without changing its genotype) - that is, he (seems to be) claiming they're transgenerational effects from the photoperiod change.

In your example it's not transgenerational, it just an example of phenotypic expression of the same genotype. And all the differences between the two plants in your example cannot be chalked up to phenotype expression, for example, less radiation per day can often mean less cannabinoid production - that's not phenotypic.

I think if you took a sativa that is used to 11 13 flower and gave it 12 12 youd get lackluster results. But thatd be something a scientist could prove with a nice side by side experiment.

Beta Test Team said:

Yes, I am. Though if someone can prove me wrong with facts, please do.

In DJ's claims, what he's saying (or appears to be saying) is the effect from his photoperiod changes the seed plants' phenotype (which can't happen without changing its genotype) - that is, he (seems to be) claiming they're transgenerational effects from the photoperiod change.

In your example it's not transgenerational, it just an example of phenotypic expression of the same genotype. And all the differences between the two plants in your example cannot be chalked up to phenotype expression, for example, less radiation per day can often mean less cannabinoid production - that's not phenotypic.

Click to expand...

To me, it is phenotype expression changing. I think u keep trying to say dj says the genotype will change, but he never says this anywhere Ive read. U are assuming that part.

Or maybe im just not understanding u. everything im talking about is phenotype expression of the same genotype. What we are talking about is epigenetics for the most part.

Isnt changing the photoperiod part of epigenetics?

When I use 11/13 on my wide leaf types, I get longer
flower times to harvest, adding two weeks, some amber,
mostly cloudy. Leaf shape mostly equal to the same cultivar
flowered at 12/12.

I also noticed growing micro in small pots, 32 oz and less,
leaves grow smaller, but never noticed 5 bladed cultivars
throwing 7 or 9 blades under 11/13.

Phenotype plasticity is there, however, you're not going
to make any dramatic changes to cultivars' expression.

Light spectrum and distance to light also play a role, but it's
a curiosity at best. Navel gazing, so to speak.

Interesting, like the dichotomy of the salts/organic thing.

Miraculous Meds said:

To me, it is phenotype expression changing. I think u keep trying to say dj says the genotype will change, but he never says this anywhere Ive read. U are assuming that part.

Or maybe im just not understanding u. everything im talking about is phenotype expression of the same genotype. What we are talking about is epigenetics for the most part.

Isnt changing the photoperiod part of epigenetics?

Click to expand...

You seem to suggest he's referring to a single plant in a single season, but he's not (well, he doesn't seem to be).

An hour change in photoperiod I doubt is going to have a similar effect on progeny ("transgenerational epigenetic inheritance") as stressors can (in terms of tags). So I doubt changing the photoperiod by an hour is going to affect the progeny, at all.

I keep referring to genotype (even though epigenetics isn't about changing the DNA sequence, rather gene expression) because DJ wrote about breeding, not growing a single plant, in terms of photoeripod effects on Cannabis.

I simply do not believe, and I won't until I see scientific evidence proving me wrong, that an 11 or 13 hour photoperiod (instead of 12 hours) for flowering can make a Cannabis plant express traits ascribed to specific genotype (like 'indica' and 'sativa') that it doesn't naturally express at a 12 hour photoperiod.

Changes in leaf and flower morphology, and even cannabinoid and teprpene production, can occur from changing the photoperiod (often due to changing the amount of daily radiation), but that's not the same thing as what DJ is suggesting.

If that didn't help clear up any ambiguity from my part I can't do any better. And honestly, this discussion about DJ is going in circles...