Dark Before Harvest, Lab results

DET—PDX

Insanely Active Member
I work for a cannabis compliance testing lab in Michigan. I recently found a video comparing the cannabinoid contents of the same plant harvested in sections regularly, 12 hr darkness, 24 hr, 48 hr and 72 hr darknesses.
48 hours darkness is most optimal for THC according to the video, ironically PSI Labs is a competitor of ours. I think we’re better.

To make a long story short, I am going to repeat the experiment with my Alaskan Thunder F*** Clones obtained from further genetics in Ann Arbor. Mom supposedly was 27% THC.

Currently, 2 plants have been in darkness about 48 hours, the rest under 24 hours. I will allow one plant to go 96 hours. 81B451CD-548F-41F5-B95A-6C9EA470B8B3.jpeg
 

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JohnFonda

Tegrity Greenthumb
I work for a cannabis compliance testing lab in Michigan. I recently found a video comparing the cannabinoid contents of the same plant harvested in sections regularly, 12 hr darkness, 24 hr, 48 hr and 72 hr darknesses.
48 hours darkness is most optimal for THC according to the video, ironically PSI Labs is a competitor of ours. I think we’re better.

To make a long story short, I am going to repeat the experiment with my Alaskan Thunder F*** Clones obtained from further genetics in Ann Arbor. Mom supposedly was 27% THC.

Currently, 2 plants have been in darkness about 48 hours, the rest under 24 hours. I will allow one plant to go 96 hours. View attachment 61507
Atf? For real. If you keep her around I'll have to grab a cut in the future. One of my favorites I ever smoked.
 

DET—PDX

Insanely Active Member
Very interested... was always skeptical about whole darkness concept
We have been very busy lately, the experiment is designed and the paperwork is ready though. The chosen plant is OrangeCookiesxChocolateDiesel. One limitation I see is the stress of cutting branches intermittently could actually increase THC as opposed to the dark treatment. I will repeat this with clones to remove this limitation next time. Although mutations can still occur and clones can differ. What are your thoughts on this? Any other limitations anyone can see? To validate anything, I’m going to need many repetitions.
 

BigBallzWillie

BE THE BALL
This came up back in September and I have been doing 2 days dark as a result of that study, since then. Works for me. It will be interesting to see your results.

 

DET—PDX

Insanely Active Member
This came up back in September and I have been doing 2 days dark as a result of that study, since then. Works for me. It will be interesting to see your results.

Saw that video with PSI in Ann Arbor. We do a better validated microbial analysis, PCR>Plating all day. I trust their potency and terpenes results though.
 
I have always chopped once my plant comes out from 24-48 hours of darkness. Only problem I have with his experiment is that he had taken it from the same plant. One would think that his first major cut in harvest would have set the plant back a few hours at minimum as it tries to repair that cut instead of working on producing more THC....
 

H.A.F.

a.k.a. Rusty Nails
One thing to factor in is at what stage you put it in darkness. If they are pretty much ready to chop, and you wait two more days (light or dark) it will continue to produce?

I have found that slow-dried makes more of a difference in a better end product. I have started watering them the morning of harvest and let them soak it all up, then chop that afternoon. For be the dark starts at 6am, so they get about half a day to soak it up.
 
Old myth not sure if proven or not that cutting into the main stem a day or two prior to harvest also produces heavier trichome production. I tried it but not an actual test. I didnt notice much of a difference in a 2 day period.
 

Oreguhnism

Really Active Member
I've read that splitting the stem should be a week or so before harvest. Bro-science though.
Nah, its pretty common to girdle the stems, where they cut away a single strip at the base when the plant matures and then leave it to dry and field cure, saw this in Tajikistan.....all over central asia this is common, also seems to happen in Albania too or more accurately a wide range of the Balkan area.....
 

inthetrees

Active Member
Great info... A friend and I were just discussing this the other day. Nice to finally see some lab results to clean up the fact from fiction.
 

Artisan_tek

Insanely Active Member
I ran this test with some clones of symbiotics kobe last year.

Left in 48 hr darkness vs harvested 1 to 2 hours before the lights went off yielded no significant change from what i can tell. might be different on paper, levels and what not but to me i couldnt tell a difference in end product as far as high goes.

i would be interested in seeing what the differences are in the terp profile
 

Skunkle Justin

Active Member
We have been very busy lately, the experiment is designed and the paperwork is ready though. The chosen plant is OrangeCookiesxChocolateDiesel. One limitation I see is the stress of cutting branches intermittently could actually increase THC as opposed to the dark treatment. I will repeat this with clones to remove this limitation next time. Although mutations can still occur and clones can differ. What are your thoughts on this? Any other limitations anyone can see? To validate anything, I’m going to need many repetitions.
I would stick with a cultivar that typically runs around 15%. I’m only saying this is because 27% THC is really close to the max amount really possible. So, if you pick a plant that won’t already be pushing the limits to start off with, she might have more room flex her dankness and creep up to 20%. Just a theory and I most certainly could be wrong.
 

DET—PDX

Insanely Active Member
I would stick with a cultivar that typically runs around 15%. I’m only saying this is because 27% THC is really close to the max amount really possible. So, if you pick a plant that won’t already be pushing the limits to start off with, she might have more room flex her dankness and creep up to 20%. Just a theory and I most certainly could be wrong.
Could be, I’ve got a theory that a plant’s not going to produce any more thc than it’s genetically capable of, but all of these are difficult hypotheses to test lol.
 

DET—PDX

Insanely Active Member
Old myth not sure if proven or not that cutting into the main stem a day or two prior to harvest also produces heavier trichome production. I tried it but not an actual test. I didnt notice much of a difference in a 2 day period.
yeah so one of the limitations of their experiment is certainly the damage done by harvest. There’s strong evidence damage can enhance cannabinoid and terpenes, but we need raw numbers, lots of them to be sure. I’m going to use clones of the same plant in the same room, etc, but even clones can mutate. There’s always going to be limitations. The experiment was put on hold because all my buddies got the orange cookies before the lab did. I’m running quite a few more plants as a caregiver now and have a proper Aeroponic cloner so you should see results around December. Stay tuned people
 

Phenosearch

Insanely Active Member
I work for a cannabis compliance testing lab in Michigan. I recently found a video comparing the cannabinoid contents of the same plant harvested in sections regularly, 12 hr darkness, 24 hr, 48 hr and 72 hr darknesses.
48 hours darkness is most optimal for THC according to the video, ironically PSI Labs is a competitor of ours. I think we’re better.

To make a long story short, I am going to repeat the experiment with my Alaskan Thunder F*** Clones obtained from further genetics in Ann Arbor. Mom supposedly was 27% THC.

Currently, 2 plants have been in darkness about 48 hours, the rest under 24 hours. I will allow one plant to go 96 hours. View attachment 61507
You would have to keep one in the light for the extra couple days also to compare accurately curious as just letting it go the extra days what the difference is assuming every day adds a little more potentcy?
 
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