What causes an auto to flower?

[Space Goblin]

What exactly initiates the flowering phase for an autoflower plant?

I ran my first auto a few months ago and it turned out great. It took off like a rocket right from the start and grew to be a couple feet tall.
I'm trying my next few autos now, and having some mixed results. I've had two Mephisto seeds pop and then do nothing until they died. I've got a couple more Mephistos that are starting off very slow - I'm wondering if it's because I'm reusing the soil this time and there isn't as much nutrients in there, so I just bumped it up a little. I also have another one that started off a little slow and now seems to be on the right track, but it just started flowering after only a month, and it's only 8 inches tall.

So I'm thinking I'm not giving them enough nutrition while they're young and they're not getting very big before flowering. (at least that one that started already), but I'm wondering if something happens with the plant that initiates the flowering or if it's purely, somehow, just TIME that causes them to start flowering at a certain point.

 

[Olderfart]

What exactly initiates the flowering phase for an autoflower plant?

I ran my first auto a few months ago and it turned out great. It took off like a rocket right from the start and grew to be a couple feet tall.
I'm trying my next few autos now, and having some mixed results. I've had two Mephisto seeds pop and then do nothing until they died. I've got a couple more Mephistos that are starting off very slow - I'm wondering if it's because I'm reusing the soil this time and there isn't as much nutrients in there, so I just bumped it up a little. I also have another one that started off a little slow and now seems to be on the right track, but it just started flowering after only a month, and it's only 8 inches tall.

So I'm thinking I'm not giving them enough nutrition while they're young and they're not getting very big before flowering. (at least that one that started already), but I'm wondering if something happens with the plant that initiates the flowering or if it's purely, somehow, just TIME that causes them to start flowering at a certain point.

Pretty much just a clock, whatever growth the plant accomplishes when time runs out is all there is going to be, flowering will begin regardless of size. That is arguably the one aspect of autos that can be a bit unforgiving. For good results, you have to avoid early mistakes that stunt early growth. There is no extra time to sort out screwups, the clock is running regardless of problems.

As to your specific issues with your grow, you should get on the infirmary section, fill in the form, provide some pics, and lots of people better at this than I am will be glad to help if they can.

Good luck with your grow.

 

[LazyNhazy]

If you are reusing soil are you checking for bugs?

 

[LazyNhazy]

Gnats can wreck a new born fast.

 

[automan2]

We all have stunted a plant or two but I've reduced mine by doing nothing but watering when they need it. Start 1/4 strength nutes at 3-4 weeks old.

 

[Proph]

What exactly initiates the flowering phase for an autoflower plant?

I ran my first auto a few months ago and it turned out great. It took off like a rocket right from the start and grew to be a couple feet tall.
I'm trying my next few autos now, and having some mixed results. I've had two Mephisto seeds pop and then do nothing until they died. I've got a couple more Mephistos that are starting off very slow - I'm wondering if it's because I'm reusing the soil this time and there isn't as much nutrients in there, so I just bumped it up a little. I also have another one that started off a little slow and now seems to be on the right track, but it just started flowering after only a month, and it's only 8 inches tall.

So I'm thinking I'm not giving them enough nutrition while they're young and they're not getting very big before flowering. (at least that one that started already), but I'm wondering if something happens with the plant that initiates the flowering or if it's purely, somehow, just TIME that causes them to start flowering at a certain point.

What makes autoflowers " automatically flower", is a Ruderalis gene strait. Flower usually starts anywhere from 18-35 days old. But it sounds like there is much more going on.. We would need to know all the details of your grow. Like OF said, you can definitely make a post in the infirmary and one of us will be able to take a closer look at things for ya... But it's the ruderalis gene trait that makes autos flower.

 

[Space Goblin]

Your answers are good, and informative, but not really diving as deep, scientifically speaking, as I'd like to go. I didn't really intend for this to become a troubleshooting thread, although if you folks are willing to science the hell out of this with me, I'll definitely go ahead and make a video and explain everything in the Infirmary. However, I will warn you that like any stoner, my explanations will tend to go on forever! But in my opinion, more information is always better.

As far as THIS thread's original inquiry goes, I understand it's genetic, but what exactly does that mean in regards of the physical, chemical, or other mechanism that would cause it to change? How does it "know" that it's 18-35 days old and start doing it's thing? Maybe only a scientist or geneticist could answer this. I know that with photoperiod plants, there is some sort of hormone that is created during the dark hours that will cause it to flower if it becomes abundant enough, which happens when the light is reduced to 12 hours. Maybe the ruderalis does something like continually create that hormone until it reaches a certain threshold, and then it flowers. Maybe nobody even knows...

 

[Proph]

Your answers are good, and informative, but not really diving as deep, scientifically speaking, as I'd like to go. I didn't really intend for this to become a troubleshooting thread, although if you folks are willing to science the hell out of this with me, I'll definitely go ahead and make a video and explain everything in the Infirmary. However, I will warn you that like any stoner, my explanations will tend to go on forever! But in my opinion, more information is always better.

As far as THIS thread's original inquiry goes, I understand it's genetic, but what exactly does that mean in regards of the physical, chemical, or other mechanism that would cause it to change? How does it "know" that it's 18-35 days old and start doing it's thing? Maybe only a scientist or geneticist could answer this. I know that with photoperiod plants, there is some sort of hormone that is created during the dark hours that will cause it to flower if it becomes abundant enough, which happens when the light is reduced to 12 hours. Maybe the ruderalis does something like continually create that hormone until it reaches a certain threshold, and then it flowers. Maybe nobody even knows...

Well, the question was pretty simple, so I gave a simple answer, lol. Which actually still answers all of the questions you have.. If you understand that it's genetic, then you should understand that genetics have EVERYTHING to do with its physical, chemical, mechanical makeup. Same as your genetics have everything to do with what makes you, you. Plants are smarter than most humans, lol. They know when they are germed, above soil and alive, sick, hungry, etc. It will show sex once its mature enough to do so. By mature, I mean having enough ethylene to cause the pistils grow.. Since most autos are fems, ethylene is the female "hormone" that causes the plant to grow flowers instead of pollen sacs.

Photo period plants do not flower based on a hormone.. They flower based on darkness.. It's called photoperiodism. How exactly these types of plants know when they are getting the proper darkness is still being researched.. Again, plants are smarter than most humans.

The ruderalis plant is constantly photosynthesizing. Most plants do not photosynthesize in the dark. Ruderalis does. It has genetically adapted to grow out its life under 24 hrs of light because of its origins. So if you understand photosynthetic classes, this tells us that autos grow like a c4 plant and not a c3. They make and use co2 in light, and even in darkness. In turn they mature faster, and have a set life cycle. Its all genetic. Bit if you want to reseach some of the elements, I'd start with ruderalis.. That's the back bone of the autoflower. That will answer a bunch of your questions and probably create a handful of new ones, lol.

 

[Son of Hobbes]

Your answers are good, and informative, but not really diving as deep, scientifically speaking, as I'd like to go. I didn't really intend for this to become a troubleshooting thread, although if you folks are willing to science the hell out of this with me, I'll definitely go ahead and make a video and explain everything in the Infirmary. However, I will warn you that like any stoner, my explanations will tend to go on forever! But in my opinion, more information is always better.

As far as THIS thread's original inquiry goes, I understand it's genetic, but what exactly does that mean in regards of the physical, chemical, or other mechanism that would cause it to change? How does it "know" that it's 18-35 days old and start doing it's thing? Maybe only a scientist or geneticist could answer this. I know that with photoperiod plants, there is some sort of hormone that is created during the dark hours that will cause it to flower if it becomes abundant enough, which happens when the light is reduced to 12 hours. Maybe the ruderalis does something like continually create that hormone until it reaches a certain threshold, and then it flowers. Maybe nobody even knows...

At one point I had heard Mark Zobel, a pretty old school autoflower breeder, talking on Facebook about a specific gene for ruderalis that allows it to flower under virtually all conditions. I know it's not a concrete answer, but I've yet to honestly see anyone GIVE a concrete answer on it on a scientific level. I did find this bit about flowering that might point in a better direction.

Genetic and physiological analysis of flowering time in Arabidopsis has led to the identification of a large number of flowering-time genes (>80) that regulate flowering time in response to environmental and endogenous cues (reviewed by Simpson et al., 1999). Regulation occurs through a complex network of genetic pathways, with two main pathways mediating environmental responses (the long-day and vernalization pathways) and two pathways that function independently of environmental cues: the autonomous pathway, which promotes flowering under all conditions, and the gibberellin (GA) pathway, which is needed for flowering under non-inductive short-day conditions. These pathways converge in the induction of floral meristem identity genes and the floral transition.

Specifically:

and two pathways that function independently of environmental cues: the autonomous pathway, which promotes flowering under all conditions, and the gibberellin (GA) pathway, which is needed for flowering under non-inductive short-day conditions.

Autoflowers are considered day-neutral and flower under virtually all conditions (ideally, we know that's not always the case.)