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Do adult plants require _SOME_ darkness?

HwyBill

HwyBill

Banned
My dad built an indoor greenhouse to try to overwinter some of this seasons plants.

Currently, it is maintained at 85F with 24 hours of Gro-lux and CFL light.

How will 24 hrs of light affect their growth and/or production?
 
In short - yes, they need some darkness. Someone will chime in with the science behind it, but they do the majority of their growing at night. I believe that light provides the energy and nighttime provides the growth.
 
The lights are on anyway. He built the greenhouse in an addition to his heated garage that he also uses to raise gamebirds in, so the lights are on 24/7 anyway.

The question is will 24 hrs of light _hurt_ their growth/production, or do I need to talk him into 18/6?
 
I'd have to agree.... Mine stay on the balcony and they have to be relocated every two weeks or so due to typhoons, the only place I can keep them currently is in a dark storage closet on the balcony.... I notice considerable growth after they've been in there for about 36 hours.... It's certainly darker in there than it is on the balcony at night....
 
HwyBill said:
The lights are on anyway. He built the greenhouse in an addition to his heated garage that he also uses to raise gamebirds in, so the lights are on 24/7 anyway.

The question is will 24 hrs of light _hurt_ their growth/production, or do I need to talk him into 18/6?
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They don'b absolutely NEED darkness in the sense of having a photoperiod and seedlings actually seem to do a little better with 24/7 light, but it's not optimal for an adult plant. But there's light and there's light - you can still easily have a 20w incandescent on and it will essentially be "dark" to the plant even though you'll be able to walk around without tripping over things.

Why are the lights on 24/7 anyway, is that how you raise gamebirds?
 
meinchoh said:
I would suggest that you Google "plant dark cycle" or "Calvin Cycle".
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Thanks for the lead.

However, the few articles I read suggest that aspects of the Calvin cycle is "light-independent" which does not necessarily imply it is "darkness-dependant"

One thing I did read which seems to suggest darkness might be important is:

Some plants synthesize the transition-state inhibitor carboxyarabinitol-1-phosphate (CA1P) in the dark. RuBP Carboxylase Activase facilitates release of CA1P from RuBP Carboxylase, when it is activated under conditions of light via thioredoxin.​

But do peppers qualify as "some plants?"​
 
Just talking out of my head right now. Without human interference (let's add some emphasis: INTERFERENCE), all living things get a period of rest roughly at some point every 24 hours. Some get more, some get less, but it seems to me that all living things, plants and animals, were designed to need periods of rest. Go on - try to force yourself to stay awake for weeks on end. At some point your body will take over and you'll pass out.

Can we survive without rest? For some time, yes. Can we thrive without rest? Not really. Do I have any technical data supporting this idea? No, I just know how I and most humans feel after periods of sleep deprivation. Birds can close their eyes and sleep in spite of the light, though they likely would appreciate if those lights were periodically turned off, too. Plants? Hm. No eyes to close. But while you can't do a direct comparison, it would seem to me that there would be some sort of negative outcome of not allowing them to rest simply because they are living things. I can see this resulting in lower seasonal production or a reduced overall life of the plant. Given the right conditions, some pepper plants will live and produce for more than a decade. It would be interesting to track some plants of one of these kinds to see if a trend can be found for a group not getting any periods of darkness.

Just my two cents.... Best wishes with your research!
 
geeme said:
Just talking out of my head right now. Without human interference (let's add some emphasis: INTERFERENCE), all living things get a period of rest roughly at some point every 24 hours. Some get more, some get less, but it seems to me that all living things, plants and animals, were designed to need periods of rest. Go on - try to force yourself to stay awake for weeks on end. At some point your body will take over and you'll pass out.

Can we survive without rest? For some time, yes. Can we thrive without rest? Not really. Do I have any technical data supporting this idea? No, I just know how I and most humans feel after periods of sleep deprivation. Birds can close their eyes and sleep in spite of the light, though they likely would appreciate if those lights were periodically turned off, too. Plants? Hm. No eyes to close. But while you can't do a direct comparison, it would seem to me that there would be some sort of negative outcome of not allowing them to rest simply because they are living things. I can see this resulting in lower seasonal production or a reduced overall life of the plant. Given the right conditions, some pepper plants will live and produce for more than a decade. It would be interesting to track some plants of one of these kinds to see if a trend can be found for a group not getting any periods of darkness.

Just my two cents.... Best wishes with your research!
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To add to what geeme has said, I know that it is recommended to reduce light exposure to plants that have just been transplanted or are recovering from a disease in order to limit the stress that is put on the plant. Plants need the light, but they need that dark time for regeneration and healing. There are little things that need healing all the time, not just big injuries, but DNA repair and stuff like that. And yes, stuff is a technical term. ;)
 
ThpSugerKuk said:
This does not need this long of a discussion. Plants dont grow in the wild under 24/7 sun... geez i wonder sometimes
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They also don't grow "in the wild" in a nutrient solution, yet hydroponic yields can be much higher than normal. "In the wild" conditions are not necessarily optimal - while plants are adapted to the (frequently very harsh) environment they live in, that doesn't imply that bettering growing conditions won't result in healthier plants, higher yields, etc. What "better" means does indeed require discussion - but more importantly, testing and experiments.
 
ThpSugerKuk said:
Hydro is simply mimicking

So are you implying 24/0 is better than 18/6? Your electricity not mine
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I'm not, which you would know if you'd read any of the previous posts. What I am saying is that it's not because of "how it is in the wild" that we know it's not better, it's because someone actually conducted a scientific experiment. But I guess that was a giant waste of time as they could have just asked you.
 
Hmm, it's not like these plants are wild plants btw. They have undergone a lot of human selection.

They will grow fine with 24 hour lighting. However, they seem to grow the most efficient under 18/6. That isn't "natural" either, hehe
 
Are you implying that they don't like to get... chilly?

horatioglasspose.jpg
 
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