Lower light levels late flower???

[Smallgrow]

Hi all,
I’m having some foxtails appearing on my buds late flower. I’ve had some other minor issues as well this grow, but it got me thinking about the practice of lowering light levels in late flower. Just wondering if others turn down light intensity near the end? Discuss……😁

I suspect my foxtails are due to too much light rather than other stress like coming up a bit short on nutrients in my living soil at the end of the run. Obviously this can be done by dimming or raising your light. My light meter was around 750 PPFD for flower which seemed reasonable, but the buds are still foxtailing. Perhaps other factors are involved in this issue as well. I’ve refreshed myself on the Foxtail sections on GWE.
​
Grow details:
Black swallow organic living soil (KIS soil mix by Tad Hussey)
Photontek x465 LED running at 75% (about 360w from the wall) about 18-20” above canopy. Approx 750 PPFD
3x4x6.5’ tent
bluemat drip watering system PH from the tap is around 6.2, 6.3 trying to keep moisture constant around 100 millibar
lights on 76F , lights off 70F
RH 45-55% in flower
6” AC infinity exhaust, 6” oscillating clip fan, 6” passive fresh outside air intake(often cold).

Genetics are Rene CBD from great gardener farms and Mango CBD from 34th street seed co. These are licensed Canadian suppliers so they should be decent but not much of a track record. Using these suppliers is the only way to be growing 100% legally where I live, so I’m trying to support that.

 

[3Berries]

I've got a 300w dimmable light and I usually add two square 50w FS cobs in my 2x4x6' flower tent. I use this for added light and heat. I cycle the 50w'ers at ~75F. But towards the end they get cut out and the 300w dimmed.

 

[SoOrbudgal]

Good call i don't think it's bad to do lowering the brightness. Your gals look awesome, gonna be a good harvest how old are they Smallgrow ? Should be harvesting looks like soon?

 

[Blowdout2269]

I unfortunately have quite the experience with foxtails. I've got overzealous with my lighting on multiple occasions.

I believe that lowering the intensity won't let the flowers suffer to much. Though it's the outer edges of your lights footprint and on lower growth where it IS somewhat noticable.
That being said, this will not help the foxtail situation much. It might slow them down a little bit, but it will not stop foxtails. The light stress cannot be reversed. This is where I make the decision. If it's late enough in flower, I just let em rage, lol. The damage is done.
Again, this is just an opinion based on my experiences.
And in this particular case, most of them ladies are way to far along to care. Nice plants!

Hope this helps ya a little. Lmk!
🙂

 

[3Berries]

I figure I nature that's what happens as the sun periods shorten and angle increases. So maybe it helps tell the plant the time is here? They are usually tall by then anyway.

 

[Smallgrow]

Yup you’re right they are in the window, both strains are between 7-9 week flowering time. These gals got germinated about October 15-17th , basically 4 months even.
I’m I trying to be patient on the trichomes. The Rene CBDs in the front of the picture are probably 30% amber now, on the top half of the plants. The Mangos are a bit behind but I want to take them down together to not complicate the drying room. There is always some added complications with harvest, isn’t there?
I have waited one more week, 3 times now 😅

 

[Smallgrow]

Yes I agree the “damage” is done. I’m just letting them go at this point and considering next time. They’ll probably end up as hash so that’s ok with me. Thanks for the input.

 

[3Berries]

I unfortunately have quite the experience with foxtails. I've got overzealous with my lighting on multiple occasions.

I believe that lowering the intensity won't let the flowers suffer to much. Though it's the outer edges of your lights footprint and on lower growth where it IS somewhat noticable.
That being said, this will not help the foxtail situation much. It might slow them down a little bit, but it will not stop foxtails. The light stress cannot be reversed. This is where I make the decision. If it's late enough in flower, I just let em rage, lol. The damage is done.
Again, this is just an opinion based on my experiences.
And in this particular case, most of them ladies are way to far along to care. Nice plants!

Hope this helps ya a little. Lmk!
🙂

You think foxtailing is a sign of high temps?

 

[Smallgrow]

Good question , my understanding is that high temps could definitely contribute. This grow I tried to go a little higher but like 77f , not actually high.

 

[3Berries]

Got to consider the IR too. It just seems to me that foxtailing, the opening up of the bud is a response to too much heat. I just end up bending the big stems over usually.

 

[Blowdout2269]

I'm actually kinda playing with my new SF4000 and building up the intensity as they age. Not only is it a new fixture to me(I don't know what it can do), I'm curious if the acclimation tactic will strengthen them towards future light stress.

Yeah, I absolutely cannot stand to trim foxtailed buds! I'll do the nice/big ones. Then get irritated and lazy about halfway through trim jail. At that point I generally just hack it all up for butter or extracts, lol.

 

[Blowdout2269]

I believe foxtailing is a symptom of light STRESS.
Whether it be intensity, distance, or length of time and temperature. It can also be genetics.

This is currently just my own speculation based of hypothesis.
This can be a good read:
https://www.growweedeasy.com/foxtails

 

[Rwise]

Sativa genetics will do Foxtails without any stress. So what is the Sativa/Indica ratio?

 

[Smallgrow]

They are both mostly saliva genetics, I’m not sure how much, especially with the breeding for higher CBD mixed in there. But they are listed simply as sativa not hybrids.
Good to know as that is mostly what I grow, and this has been an ongoing problem for me.