Different types of plant stress, 1:(LAR), 2:(SAR), 3:(SGS), 4:(ISR), 5:(SWR)

Advanced Techniques
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And in fact too! :+1:

:evergreen_tree: :salt: :herb:

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Here are brief explanations of the different types of plant stress :

  1. LAR (Low Active-Rhizosphere) Stress: This type of stress occurs when there is a low level of activity in the soil around the plant’s roots. It can be caused by factors such as poor soil structure, low nutrient availability, and waterlogging.

  2. SAR (Systemic Acquired Resistance) Stress: This is a type of stress response in which the plant develops a systemic resistance to pathogens and other stresses after being exposed to them. This response is triggered by the production of signaling molecules and can help the plant better defend itself against future stressors.

  3. SGS (Systemic Growth Signal) Stress: This type of stress occurs when the plant is under stress and produces a systemic signal that triggers growth in other parts of the plant. This can help the plant allocate resources to areas that need it most.

  4. ISR (Induced Systemic Resistance) Stress: This is a type of stress response in which the plant produces compounds that help it resist pathogens and other stresses. This response is triggered by the presence of beneficial microorganisms in the soil or on the plant’s surface.

  5. SWR (Soil Water Repellency) Stress: This type of stress occurs when the soil becomes hydrophobic and repels water, preventing the plant from taking up water and nutrients. This can be caused by factors such as soil compaction, high temperatures, and low organic matter content.

Several environmental stress factors have been shown to dramatically increase cannabinoid production in cannabis plants.

It’s important to note that the effects of these stress factors on cannabinoid production can vary depending on the specific strain of cannabis and the growing conditions.

In addition, while some stress factors may increase cannabinoid production, they can also have negative effects on plant growth and overall yield.

Therefore, it’s important to carefully monitor and manage environmental stresses in order to optimize both cannabinoid production and plant health.

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@JoeCrowe
You may find this interesting.

This paper reinforces what you keep telling us.
You can increase cannabinoid production but trichome density seems to be unaffected.
Like it is determined genetically… :wink:

Exogenous_application_of_stress_related.pdf (1.2 MB)

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Dunno where to put this, so here is a good place.

I think this is saying that cannabis can produce a poision.

Glandular trichomes, which secrete lipophilic substances,can serve in chemical protection against herbivores and pathogens by deterring or poisoning them. Moreover, trichomes can be both production and storage sites of phytotoxic materials(Werker, 2000). In

H. perforatum

plants the phototoxin hypericin accumulats in secretory glands on leaves and flowers (Fields et al.,1990;Zobayedetal.,2006).I

@Cormoran what is your take on this?
When you get the time of course. :smiling_face_with_three_hearts:

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I wasn’t able to follow any of the links - the references are loop-backs and the google drive tells me to request access - so I’m not sure on the article you were quoting; does it specify that those plants they found secreting hypericin are actually cannabis? It looks like they’re talking about St. John’s Wort - Hypericum perforatum. A google search of the two terms together doesn’t yield much; most of the discussions of hypericin are about St. John’s Wort. If cannabis does contain it, I’d say it depends on the dosage and the delivery mechanism. St. John’s Wort can be toxic, but it’s also used as an herbal antidepressant in small doses. In fact, interestingly enough, St. John’s Wort appears to only work as an antidepressant due to the entourage effect. :wink: At least, that’s what this article says. It doesn’t really contain any references, so no idea how reliable it is, but if so it’s kinda neat. It’s also one of the only references I found to hypericin and cannabis together.

On its own, hypericin seems to be used as an anti-viral and anti-cancer skin care treatment, after some tinkering with nanoparticles to avoid the photoactivated toxicity. Again, in smaller doses it’s harmful to the skin but not actually a systemic poison, so even if it is in cannabis the dosage is the sticking point, as well as whether it would even be activated.

https://www.sciencedirect.com/topics/immunology-and-microbiology/hypericin

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I thought it did… :woozy_face:
I am sorry for the wild goose chase here.
Apparently, the reference was to St. John’s wort plants and I missed that reference.
My eyesight is getting bad and I tend to skim the article at times. :face_with_monocle:

Journal of Biotechnology

Volume 143, Issue 2, 20 August 2009, Pages 157-168

Journal of Biotechnology

Elicitation studies in cell suspension cultures of Cannabis sativa L.

It would seem I was in error… here is the quote.
(Taura et al., 2007a). Glandular trichomes, which secrete lipophilic
substances, can serve in chemical protection against herbivores and
pathogens by deterring or poisoning them. Moreover, trichomes
can be both production and storage sites of phytotoxic materials
(Werker, 2000). In H. perforatum plants the phototoxin hypericin
accumulats in secretory glands on leaves and flowers (Fields et al.,
1990; Zobayed et al., 2006). It has been confirmed that cannabinoids
are cytotoxic compounds and thus they should be biosynthesized
and accumulated in highly specialized cells such as glandular trichomes (Morimoto et al., 2007)

Thanks for checking it out, but sorry for the run around here. :relaxed:

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Salicylic acid
Gaba
Uv
Ozone
Wind
Chitosan
Melatonin
Mannitol or similar sugar osmotic stress inducer
Jasmonates
Harpin protein from gmo ecoli piss.
Ethylene

beneficial bacteriums like:
Bacillus D747

Good luck.

P.s
I threw everything out n started fresh in a small room i will automate because its too damn much work when u have a day job and hours of mixing and prepping hormones so ima do a 6 gallon 2x3 grow maybe i can try to schedule n test all the above plus more shit i use like K Acetate (in green dragon).
Too much of any of this shit will hurt yield but when u pull kush mintz bud apart and it oozes u know u did it right.

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How do you apply melatonin? Thanks

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I had a dropper from amazon but had other preservatives not ideal so i order pure powder from that orange bulk supplier. Just mix with RO but havent tried it yet as a powder.
It seems 30ppm is the magic mark for many leafy plants and probably should be sprayed towards the end. I used it last time forgot exactly ppm but twice late flower. No harm but had no control. Temps were right and i had good results so no idea but no harm. Its natural and in many studies it kinda mimicks auxin and ethylene but it also does the opposite. The affects are amazing across the board in the research papers.
U can skip to materials, results, pics, and conclusions on this one Frontiers | Preharvest melatonin foliar treatments enhance postharvest longevity of cut tuberose via altering physio-biochemical traits

And thanks for the opportunity to shine light to a goy on a sabbath.

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:handshake: thank you

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I would love to hear more about this if you have the time.
I really don’t have an issue getting K into the plant, in fact, I probably have too much on a regular basis.
Or at least I think I do, no tests have been done.
It would seem K Acetate works best as a foliar spray.
How do you use it?

Would this disrupt the feeding process?

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Im starting another growlog as i harvested i can update pics soon in my current one.
Mannitol is in my reply to terpinator patent i found using it as 5% i think.
It helps with a lot of other stuff too.
Im not sure if it triggered trichome or sweet taste
I got no burn from k acetate both foliar or drench. No harm until i ozoned them too much by accident lights on and gnats my fault as i used too much organics or didnt ph all my soup.

Everything came out frosty and no cure tastes great and crumbles great best taste i ever got just slow dried testers.
Mallatonin at like 25ppm no harm end of harvest once a day.

Ill have a tamer setup and should test better soon. Ill miss the lower temps at harvest :frowning:
Unfortunately no control until i have a better setup or two small clones outdoors. Its a lot of work to mix this shit especially fresh and keep track

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Thanks for the response, it seems you and I are the only ones in the world doing these sort of things.
Or we are the only ones talking about it anyway.

The microbes just love the sugars, almost nothing keeps them away.
I wonder what the big commercial guys use for anti-microbial?
Probably something nasty…LOL

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Yes some will eat mannitol. Sorbitol can be sprayed as a pesticide

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Very cool!
I found this…
erythritol was identified as the most potent and promising insecticide among sugar alcohols

Laboratory evaluation of sugar alcohols for control of mosquitoes and other medically important flies - PMC.

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Don’t overwater your plants in the last few weeks.
Why?

Marijuana has been shown to significantly increase THC and CBD concentration within the floral portions of the plant when exposed to drought in the last two weeks of flowering (Caplan et al., 2019),

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Notably, the largest change was observed after 7 days of drought stress, when plants showed a 40% greater accumulation of CBG (control: 336 μg/g; treatment: 622 μg/g), and a significant decrease (70–80%) in CBD (control: 1182 μg/g; treatment: 297 μg/g) and THC amounts (control: 3927 μg/g; treatment: 580 μg/g).

Conclusions

Although this observation is limited in the early flowering stage, the common field stresses are adequate to induce changes in the cannabinoid profiles, particularly drought stress being the most impactful stress for hemp flower initiation with the altering the cannabinoid production by decreasing CBD and THC accumulation while increasing CBG by 40%.

And remeber…CBGA is naturally converted into CBDA and THCA—which can later be converted into CBD and THC when activated by heat ,

@DirtySlowToes and @navy66

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Thanks for sharing! I read it, but I’m confused a little – don’t you mean “don’t over (or under)water in the FIRST few weeks (of flower)”?

My take on the study was, stress early in the flowering stage will likely result in shitty weed.

Am I wrong? (not being a smart-ass – for once) :wink:

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You are correct, that is what this study showed.
This was just one study, there are more.

I also quoted this in your other thread but forgot to post it here…

Research performed in high-THC cannabis has shown that late and mild water stress can increase THC levels (Caplan et al., 2019). It is hypothesized that secondary metabolites are produced as a defense mechanism against stresses such as herbivory attacks (Jackson et al., 2021).

What do we know??
We know that drought stress at the wrong time can affect yield and quality.
We also know that drought stress at the right time can increase quality/potency.

When is the wrong time?
At the start of flower.

What is the best time?
When it will not affect yield.

When will it not affect yield?
Late in the flower cycle.

I do not suggest ever over-watering your plants unless you can not be there to tend them, then you must do what you need to to keep the plants alive.

But I do agree that the first few weeks of flower are important and you definitely do not want to underwater or over water in the first few weeks of flower.

But water/drought stress late in flower is best for secondary metabolite production.

While this is true of drought stress, generally stress mostly affects yield, potency may or may not follow along that same path depending on certain circumstances and types of stress.

There is always a trade off when dealing with stress.
If done right the trade off is often very beneficial in the end.

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@shag Very helpful, Shag. Thanks. As I novice, I’m fascinated by this. It makes intuitive sense to me, too, about certain late-flower stressors actually improving the flower “chemically,” though not “structurally.” This is an area I’m likely to focus in on in the future.

Take, for example, stem splitting on the main stalk. What kind of stressor is that? Does it “chemically” (my word for terps, trichs, metabolites, etc.) change things? How does it do that?

To me, intuitively, anything the plant experiences in late flower that is a) consistent with autumn weather and more importantly b) that weather’s relative difference to its previous climate (veggie) is likely to help with the chemical development.

That’s sort of my working theory. So when I say this subject is likely one I’ll want to test more specifically, that’s what I mean.

(To crystallize my example, if the plant thinks its time is coming due (not early flower, but late flower), it will help. Light and light wavelength is just one. But what else? I don’t think “flushing” helps taste – but I feel like a wholesale flood would possibly mimic autumn, in that it would radically change the soil relative to its earlier nutrient load – and the change itself could be the trigger. I’m more interested in finding how if/how flushing affected bulking, terps, drying, etc. – if I wanted great taste, I’ll eat a Lifesaver.)

Sorry, just thinking out loud. I appreciate you throwing wood on my thought fire. :slight_smile:

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This thread may very well be the best nfo on the web when it comes to stress and cannabis.
It is worth reading several times, I often review it cause that is a lot to remember.
I am not a fan of flushing but I feel feed should be reduced late in flower.

Thanks to @JudasCreeps for this info.
Not a bad way to feed your plants, and no you don’t need 7 different ferts, you simply adjust your feeding program to hit close to these numbers.

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