48 hours of dark

[Autofacade]

Asking for a friend.....

I have 4 of one plant 1 of another. The 4 are ready for the chop but the last has about a week to go. Ideally they have to stay in the tent. He wants to do the 48hours of dark before he harvests. Would the one that is not ready yet be affected too much if it was to have a 48 of dark and then back to 12/ 12 for the rest of the week?

I was very interested by this. Wanted to see what your thoughts would be

 

[BooMtoLate]

He could take the one plant out and throw it in a window somewhere

 

[Weaselcracker]

Does anybody actually know if a pre-harvest dark period really accomplishes anything at all? Maybe it does. A few good growers do it. Nobody seems to know for sure.

It’s trading two days of definite growth development in the earlier plants, for... what?

 

[derek910]

Asking for a friend.....

I have 4 of one plant 1 of another. The 4 are ready for the chop but the last has about a week to go. Ideally they have to stay in the tent. He wants to do the 48hours of dark before he harvests. Would the one that is not ready yet be affected too much if it was to have a 48 of dark and then back to 12/ 12 for the rest of the week?

I was very interested by this. Wanted to see what your thoughts would be

He could just let the 4 go a week longer. Depending on where they are 1 more week shouldn’t hurt.

 

[Autofacade]

Cheers for all the responses people!

 

[DrCannaCanadian]

Asking for a friend.....

I have 4 of one plant 1 of another. The 4 are ready for the chop but the last has about a week to go. Ideally they have to stay in the tent. He wants to do the 48hours of dark before he harvests. Would the one that is not ready yet be affected too much if it was to have a 48 of dark and then back to 12/ 12 for the rest of the week?

I was very interested by this. Wanted to see what your thoughts would be

Great question!

I think @derek910 has a great idea which will let all the plants finish up successfully - and at the same time. After 1 week put all 5 plants into 2 days of darkness - then harvest them all.

The 48 hours of darkness is supposed to stress the plant to increase the number and quality of the trichomes (THC & Terpenes). I believe @Emilya has this documented somewhere that it works and even did it in her last grow.

The original question though is about what effect 48 hours of light deprivation has on a plant. That is, stopping photosynthesis completely for 48 hours!

With 48 hours of light deprivation on a photoperiod in veg, we can actually speed up the transition from veg to first pistils by increasing the speed at which red receptors turn into far-red receptors. It is the presence of the far-red receptors releasing hormones which actually trigger the plant to go into bloom.

As an aside, basically there is a 4 week harvest window before the plant degrades so much it just up and dies.

Also, moderate light deprivation has been proven as a technique to speed up the flowering process.

Back to the question now - A plant that is one week away from harvest has stopped developing - it has stopped growing - and it knows it is dying.

We are also talking about complete light deprivation for 48 hours, which may stress the plant out so much that it follows its natural biological program to survive by becoming a hermaphrodite.

In conclusion, with 48 hours of light deprivation on a photoperiod in late bloom, that fifth plant is going to be closer to harvest with more quality trichomes - but, it may actually become a hermie due to the stress.

Warning: Feed your plants before the 48 hours of darkness and then check closely, every 8 hours, for mould and rot! Decrease the humidity to about 35% if you can - that will help against the mould spores taking hold and ruining your harvest.



Please skim or read these when you can find some time, you may find them helpful:

Cannabis Hermaphroditism: What Is It, And How Can You Deal With It?


What Is Light Deprivation And How Does It Affect Cannabis?

 

[Emilya Green]

Asking for a friend.....

I have 4 of one plant 1 of another. The 4 are ready for the chop but the last has about a week to go. Ideally they have to stay in the tent. He wants to do the 48hours of dark before he harvests. Would the one that is not ready yet be affected too much if it was to have a 48 of dark and then back to 12/ 12 for the rest of the week?

I was very interested by this. Wanted to see what your thoughts would be

its not optimal, but the slow one will continue growing, just as the others do who are getting ready for the chop. The slow one will also develop better trichomes during this period, since there will be no light to degrade them.
48 hours is just long enough to get the plant a little concerned, but it will bounce right back as soon as it sees light again. Imagine a very dark 2 day late fall storm, that blocks out the sun for 2 days. The plant will survive it just fine.

 

[BeanTownFan420]

But if it hermies does that even matter cause your harvesting it before it can make usable pollen.

 

[DrCannaCanadian]

its not optimal, but the slow one will continue growing, just as the others do who are getting ready for the chop. The slow one will also develop better trichomes during this period, since there will be no light to degrade them.
48 hours is just long enough to get the plant a little concerned, but it will bounce right back as soon as it sees light again. Imagine a very dark 2 day late fall storm, that blocks out the sun for 2 days. The plant will survive it just fine.

Thanks @Emilya ,

So we're okay with about 48 hours - but maybe at around 72 hours it may hermie. There must be some threshold.

 

[BeanTownFan420]

 

[DrCannaCanadian]

But if it hermies does that even matter cause your harvesting it before it can make usable pollen.

Yes - that is true.

But the question is about what happens if you let it keep growing after the 48 hours.

@Emilya says it will bounce back after 48 hours - but I'm thinking at some threshold- maybe 72 hours, it will hermie - and then if the plant is left to keep growing, it will create pollen and thereby degrade the quality of the harvest.

 

[AdaminCO]

I ran a 24, 36, 48 hour dark. 36 was optimum. I didn’t see any difference between 36 and 48.
I think @Emilya ran back to back experiments with me at that time and we both came up with the same “sweet spot”.
Hold 36hrs.

 

[AdaminCO]

I ran a 24, 36, 48 hour dark. 36 was optimum. I didn’t see any difference between 36 and 48.
I think @Emilya ran back to back experiments with me at that time and we both came up with the same “sweet spot”.
Hold 36hrs.

Let me correct myself. Just refreshed my memory. 36 hours is the optimum for compost tea brews. 72 hours max for hold over.

6 Ladies Cloned Trifecta, 2019, Indoor 4x8 LED

https://www.420magazine.com/community/forums/420-contests.312/ :Namaste: Thank you sir!

www.420magazine.com

 

[DrCannaCanadian]

Thanks @AdaminCO - nice reference!

Alright @Autofacade , you can tell your friend they can safely do up to 72 hours of darkness then chop on the first four plants.

And please let us know what happens to the fifth plant that is flipped back to 12-12 after the 48 hours of darkness.

 

[AdaminCO]

Thanks @AdaminCO - nice reference!

Alright @Autofacade , you can tell your friend they can safely do up to 72 hours of darkness then chop on the first four plants.

And please let us know what happens to the fifth plant that is flipped back to 12-12 after the 48 hours of darkness.

I’m not sure about flipping them back.
If they are down for experiments, that yeah go for it.
What I (literally) just did was pull the plants out of the tent that were ready, and stuck the in the guest bedroom closet for the dark period.
I think you’ll nanner trying to light it up after 48-72 hours in dark.
Bout if you’re down for the experiment, I’m willing to learn.

 

[DrCannaCanadian]

I’m not sure about flipping them back.
If they are down for experiments, that yeah go for it.
What I (literally) just did was pull the plants out of the tent that were ready, and stuck the in the guest bedroom closet for the dark period.
I think you’ll nanner trying to light it up after 48-72 hours in dark.
Bout if you’re down for the experiment, I’m willing to learn.

That's exactly what I'm thinking.

If I remember, I'll try it one plant - I've never seen a real hermie before

 

[AdaminCO]

That's exactly what I'm thinking.

If I remember, I'll try it one plant - I've never seen a real hermie before

It happens.

 

[Modest Grower]

Very interesting. I'm interested in doing this dark period for my autos and switch from 18/6 to 12/12 after the dark period for the photos I have going. Happy Friday!

 

[Autofacade]

Wowwy I well I wasnt expecting such a in depth response from so many people! Thankyou very much to all! @Emilya @AdaminCO @DrCannaCanadian.
I will update you on the process guys lets see what happens!

And thankyou to everyone else who wrote in also!

 

[Emilya Green]

a word about hermism... While a stressor like what we are discussing could very well trigger a hermi response in the plant, with a week to go this is not at all a worry... it is not like the plant is going to immediately produce pollen, pollinate itself and produce seeds, all in a week. Give the plant another 3 weeks and it could be an issue... but here, not even a concern.