Providing an artificial trigger for senescence

[xerb]

Hi Folks,

I have been thinking about senescence and its possible effect on the finished product.
Based on what I have seen, it seems that once this process has started it can't be turned off.

So my question is:

Why can't senescence be triggered artificially at some point in the flowering process?
I've had things happen in my grow that starts senescence half way through the budding cycle,
and the final product from these grows are typically outstanding in terms of quality.

Wouldn't this encourage the plant to finish up - ripen more quickly?

Some of the triggers I have seen would be easy to re-create in the grow room.

One night of cold temperatures (like when the power goes out) can start it.

A short dry spell that stresses the plants can also bring the onset of senescence.

I have always tried to keep my plants happy and growing as fast as possible, but maybe I have been missing something?
Maybe a bit of stress at just the right time would allow them to develop more naturally, perhaps even make the trichomes swell.

Does anybody try to manipulate this transition to senescence indoors?
What would the optimum timing be?

Early, like 1/2 way through the flowering cycle - or late like
the opening of the first harvest window?

XERB

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[Mattbho]

My best plants are grown organic and chopped almost dead. they decide when to finish.


I've heard ice baths wlll start it .

This might be up your alley
Controlled Drought Stress
https://www.researchgate.net/publica...Drought_Stress

 

[Brother Nature]

You should check out the 'flushing is a myth' thread. There's a bit of BS to wade through, but the answers to your questions are there.



https://www.icmag.com/ic/showthread.php?threadid=364136

 

[xerb]

3 main triggers - are there others?

3 main triggers - are there others?

Thanks for the link Bro!

Thank you too Matt, but for some reason your link didn't work


I can think of three possible triggers for senescence:

1. Water availability
2. Temperature
3. A change in the light spectrum

Even in outdoor grows, I have seen crops that were not stressed and the onset of senescence was delayed.

Perhaps these plants were not acclimated to the local conditions?

Other years a cold snap tells the plants to finish and a major increase in frostiness occurs almost overnight.

XERB

 

[Switcher56]

I had plants go into senescence unknowingly, waiting for amber trichs (some) that never materialized. From that grow, I have been able to time my flush to coincide with the beginning of senescence and have it full blown by the time I harvest my girls (a guess (WRT full blown)). A total run for me is 22 weeks from sprout to harvest. I veg for 8 weeks but in reality it is more like 10, because the 1st 2 weeks I call them seedlings. The flowering time OTOH will vary, but the veg is always the same, and may be as low as 6 weeks or a total of 8 weeks (when I do a 6 week veg) which I haven't in a while.

Does it make my weed "danker", I don't know, as I have nothing to compare it against, as I grow various strains each run. I do know that my weed is better now than when I started (strains I have grown more than once). Is there a correlation, I don't know. But, if it works, I simply no longer question it. e.g it is what works for you, in your growing conditions and environment and everyone's mileage will vary, based on the latter.

 

[Weird]

the triggers are not static across all genetics and methods


lighting variance triggering senescence is not required for auto is one example

 

[Cvh]

 

[xerb]

Brother Nature, thanks again for the link - I found exactly what I was looking for by following the links within the link!

There are 3 main triggers for Senescence: LIGHT, Temp, and Water Stress.

According to this paper, Red and Far-Red light act as inhibitors to senescence.

It turns out that as the sun has to pass through more atmosphere, due to a shallower angle in the fall and winter, more of the red and far red are filtered out by clouds and water in the air.

Having thought about this for a while now, I am going to change the schedule for lighting the flower room, starting with 11/13 for most of the flowering cycle, but then decreasing it about 10 minutes a week when I want the senescence to really kick in.

I may also play with the spectrum they receive by changing the bulb in my HPS to something with less Red/Far-Red (just for the last few weeks).

A couple weeks before harvest, I will give them a bit of water stress - even to the point of letting them wilt, once, very near the end.

Starting about 3 weeks before anticipated harvest, I may try exposing the soil to cold temperatures as well. I am still kicking around ideas on how to accomplish this.

I wonder if soil temps dropped to 50 F, if that would be enough to
stress them? Bring on the frost and colors! XERB

 

[CrustyCruz]

Protein phosphorylation is a reversible post-translational modification of proteins in which an amino acid residue is phosphorylated by a protein kinase by the addition of a covalently bound phosphate group.

 

[CrustyCruz]

The standard used to be feeding the microbes a bunch of crap so they stop breaking down carbon nutes for the plants. Unfortunately the plant uptake some of that crap directly and ruins the flavor... We still waiting on the forums to accept that plants will uptake sugars tho.

Theres also boiling the roots. Which of course has turned into another myth. I'm trying to find the literature from the 1800s that explains it better than I can,but essentially you remove oxygen from the root zone and simultaneously force stomata to close.

 

[Scrogmeister]

I accidentally found it one time through lighting. I was running lights at 11/13 for ZamalDelica and I had a Blue Dream in the tent with it. Without knowing it I watched how the buds developed into rocksolid nuggets, differently than others I’ve grown. Once Zam finish I added in a second Blue Dream under the same schedule of 11/13. While the volume was no different, and maybe slightly less, the buds were/are outstanding. Now cured for six months and, along with ZamalDelica, are top shelf in the candy store

 

[Weird]

Developmental senescence is composed of several triggers relative to cultivar and methodology





https://www.plantphysiol.org/content/1
Living to Die and Dying to Live: The Survival Strategy behind Leaf Senescence

Under optimal growth conditions, the onset of leaf senescence occurs in an age-dependent manner (Schippers et al., 2007). Leaf senescence involves a complex interplay between internal and external factors, which determine the timing, progression, and completion of senescence. The model plant species Arabidopsis exhibits two types of senescence: sequential and reproductive senescence. During sequential senescence, older leaves senesce and their nutrients are translocated to younger, growing parts of the plant. This type of senescence is independent of reproduction, since male and female sterility increase plant longevity, while the lifespan of individual leaves remains unaffected (Noodén and Penney, 2001). Reproductive senescence occurs at the whole-plant level in monocarpic plants (Fig. 1) and promotes seed viability and quality. First, we will introduce the concept of developmental senescence and the senescence window. We will then provide a concise overview of the role of plant hormones in the timing and progression of senescence.

 

[gizmo666]

I'm not a seasoned grower but a deep thinker
Could this be the reason in the last couple of weeks due to light change and also starvation of nutrients the buds fatten more or is this just a natural plant reaction
I'm asking as I'm in the last two weeks of my grow and two weeks approx ago I changed my light to 13 off 11 on and tbh haven't noticed any great change in the plants

 

[prune]

I'm guessing you nim-wits are all premature ejaculators...

 

[gizmo666]

I'm guessing you nim-wits are all premature ejaculators...

Noob question it may be
But with a seasoned grower like yourself wouldn't something a bit more constructive be helpful after all we all had to start somewhere
After all I want to be able to cultivate great plants but rely on advice and guidance from folks way ahead of me
But thanks for the input now I know I've asked a severe Noob question
But maybe a better more helpful grower Will answer a noob and help them on the way to enlightenment

 

[Switcher56]

I'm guessing you nim-wits are all premature ejaculators...

Great contribution, not! There is no such thing as a stupid question. Just the one that never gets/got asked!

 

[iloveweed123]

I'm not sure where i read it or maybe I dreamt it , but doesn't drilling holes or putting nails in the main stem have something to do with senescence?. Maybe it's a old wifes tale to get them to sparkle up, i don't know

Only way i know of that I do is to lower feed and knock a hr off the light cycle about 3 weeks from finish

 

[Switcher56]

... old wives tale. I tried it... it's BS!

 

[trichrider]

I'm guessing you nim-wits are all premature ejaculators...

when the fires of passion flickering fade....

 

[xerb]

I'm not a seasoned grower but a deep thinker
Could this be the reason in the last couple of weeks due to light change and also starvation of nutrients the buds fatten more or is this just a natural plant reaction
I'm asking as I'm in the last two weeks of my grow and two weeks approx ago I changed my light to 13 off 11 on and tbh haven't noticed any great change in the plants

Hey Gizmo, , good questions.

A couple of things to keep in mind, not all strains need this kick in the butt to get senescence started.
If your strain doesn't, you may be slowing it down in the home stretch by reducing the light energy available to it.

In my experience growing sativas, there does seem to be a magic couple of weeks where the buds and trichomes really get with it.
If you think about it, we are really growing trichomes, and in the last few weeks the buds put on a tremendous amount of weight, mostly trichomes.

Low temperatures seem to have a great effect on the buds near ripeness, colors and frostiness just pop.

I think that senescence plays a big part, especially with long flowering sativas.
Waiting for the plant to finish, sometimes seems to take forever.
The first harvest window may have come and gone, new growth forming again.
This cycle often repeats over and over, eventually male flowers forming.
This is something you pre-mature harvesters will never see.

This time I will try to induce senescence with water stress and cold temperatures.

I have grown this strain so many times I have a pretty good baseline to compare to.
With the Burmese I am growing now, I will let it grow until I see too many little yellow male flowers forming inside the buds.

Best of Luck, XERB