This seedling stretching too much?

Horselover fat

Well-Known Member
Those buckets might warm up quite a bit from the light. Keep an eye on it. My water got up to 30c/90f due to led light when ambient temp in the tent was 25c.
 

curious2garden

Well-Known Mod
Staff member
Ok, explain to me what happens during the dark that doesn't happen during the day. Now you're just saying you are right.
I do not believe sharing my anecdotal experience is stating I'm right. It's stating I've thought about it and although I'm not a plant physiologist in an environment where I can actually run a controlled experiment I have done some work to test the hypothesis for myself.

If you wish to read my take on this @rkymtnman and I had a thoughtful discussion on it here:
 

Horselover fat

Well-Known Member
I do not believe sharing my anecdotal experience is stating I'm right. It's stating I've thought about it and although I'm not a plant physiologist in an environment where I can actually run a controlled experiment I have done some work to test the hypothesis for myself.

If you wish to read my take on this @rkymtnman and I had a thoughtful discussion on it here:
I see! Yeah, there can be situations where the dark period is beneficial for the grow. I can appreciate your reasons.
 

cannabineer

Ursus marijanus
Ok, explain to me what happens during the dark that doesn't happen during the day. Now you're just saying you are right.
Allow me to take this over from Annie (@curious2garden). She comes from medicine, the poor dear, and what I bring to this table isn't surgical precision but chemical pedantry.


Cannabis metabolism, both photosynthetic and in photorespiration, runs on the Rubisco enzyme. This has two modes: the Calvin cycle as energized by photosynthesis, and photorespiration which happens in the dark.


The fact that the plant is actively using resources in the dark (and not just shutting down until light returns) means that there is a benefit to that resource use. The Rubisco enzyme is no longer double-tasked to photosynthesis AND housekeeping. If there were no benefit to doing it lights off as opposed to lights on, the nighttime activity would be an unnecessary drain on resources, a situation generally acted on by evolutionary pressure.





Here's a link to Rubisco; it explains the dual reaction mode and its consequences.





 

curious2garden

Well-Known Mod
Staff member
Allow me to take this over from Annie (@curious2garden). She comes from medicine, the poor dear, and what I bring to this table isn't surgical precision but chemical pedantry.


Cannabis metabolism, both photosynthetic and in photorespiration, runs on the Rubisco enzyme. This has two modes: the Calvin cycle as energized by photosynthesis, and photorespiration which happens in the dark.


The fact that the plant is actively using resources in the dark (and not just shutting down until light returns) means that there is a benefit to that resource use. The Rubisco enzyme is no longer double-tasked to photosynthesis AND housekeeping. If there were no benefit to doing it lights off as opposed to lights on, the nighttime activity would be an unnecessary drain on resources, a situation generally acted on by evolutionary pressure.





Here's a link to Rubisco; it explains the dual reaction mode and its consequences.





I think the cookbook and robe were a nice graduation gift from that Ph.D. program but don't hurt yourself with that pointy stick they gave you, little prince. I dislike enucleations. Gratuitously, stop running with scissors. But you do have my point about Rubisco correct. Thank heaven you organicers are good for something.

:eyesmoke:
 

cannabineer

Ursus marijanus
I think the cookbook and robe were a nice graduation gift from that Ph.D. program but don't hurt yourself with that pointy stick they gave you, little prince. I dislike enucleations. Gratuitously, stop running with scissors. But you do have my point about Rubisco correct. Thank heaven you organicers are good for something.

:eyesmoke:
The wand chooses the wizard, Harry.
 

Horselover fat

Well-Known Member
Allow me to take this over from Annie (@curious2garden). She comes from medicine, the poor dear, and what I bring to this table isn't surgical precision but chemical pedantry.


Cannabis metabolism, both photosynthetic and in photorespiration, runs on the Rubisco enzyme. This has two modes: the Calvin cycle as energized by photosynthesis, and photorespiration which happens in the dark.


The fact that the plant is actively using resources in the dark (and not just shutting down until light returns) means that there is a benefit to that resource use. The Rubisco enzyme is no longer double-tasked to photosynthesis AND housekeeping. If there were no benefit to doing it lights off as opposed to lights on, the nighttime activity would be an unnecessary drain on resources, a situation generally acted on by evolutionary pressure.





Here's a link to Rubisco; it explains the dual reaction mode and its consequences.





Uhm, I think you're confused. I could be too, but I think it's you. In my understanding photosynthesis consists of the light cycle and the dark cycle. In the light cycle light is harvested and atp & nadph are produced. Those are used to power the dark cycle, in which rubisco is used to fix carbon. Instead of co2 rubisco sometimes fixes oxygen and it is a wasted cycle, because no energy is produced and that is called photorespiration. Despite the name dark reactions take place in the light too. They are light independent. During the night the dark cycle continues on stored atp and nadph.
 

cannabineer

Ursus marijanus
I don't get how that paper is relevant. If you are referring to the dark cycle it doesn't mean it takes place at night. It means it's light independent as in it doesn't need light. At night the light cycle can't function so in the dark only the dark cycle continues and it continues as long as there is stored energy from the light cycle.
It's not about the dark cycle but about photorespiration and why it takes place at night to the plant's benefit.
 

Horselover fat

Well-Known Member
If that were the case, the housecleaning wouldn’t go on at night. It consumes plant resources at night. This would not happen unless the plant gains a definite benefit greater than the resources used, a benefit that needs a dark period.
The photorespiration is when the dark cycle tries to use an oxygen instead of a co2. This only reproduces the energy put in and doesn't produce additional energy. It happens randomly.
 

cannabineer

Ursus marijanus
The photorespiration is when the dark cycle tries to use an oxygen instead of a co2. This only reproduces the energy put in and doesn't produce additional energy. It happens randomly.
Photorespiration and the dark aka Calvin cycle are two different things. The terms are not interchangeable.
 
It looks normal to me. Stand up with support if needed (toothpick) and keep light close. It will take off. Use Rockwool plugs in the future, those brown butt plugs don't keep the perfect moisture/air mix, they get too wet and can rot clones and seedlings. Rockwool is idiot-proof.
 

Horselover fat

Well-Known Member
Photorespiration and the dark aka Calvin cycle are two different things. The terms are not interchangeable.
Yeah, please read what I write or read the khan article you posted. It explains phototespiration very well. Actually let me quote the very beginning of the article:

"Photorespiration
Photorespiration is a wasteful pathway that competes with the Calvin cycle. It begins when rubisco acts on oxygen instead of carbon dioxide."
 
Top