Stress or optimum: what makes for hotter fruits

Just stirrin'!  I have already arrived at a conclusion however I am interested in hearing from y'all.
Scenario 1: everything the best it can be.  Plants big and lush (1m tall x 1.5m spread), lots and lots of flowers and fruit.
Scenario 2: plants are stressed.  Plants short (half the size of those in scenario 1), not particulalrly leafy, fewer fruits and flowering basically finished already.
Don't pay too much attention to the hypothetical parameters - Scenario 1 has everything and would be viewed as perfect or at least nearly-so for the species/cultivar.  Scenario 2 are obviously stressed and have not had the same level of inputs and can therefore be considered to be stressed due to limiting factors.  If you saw them you would reckon they look pretty crap and not excatly a poster child for the species/cultivar.
NOW: the Q is - which of these would produce the hottest fruits?  Post your answer with your reasons why.
In the perfect world, the stressed plant will produce hotter fruit, This is the plants survival mode of it's future generations to assure no susceptible to capsaicin creature will devour its only chance to reproduce.
You can stress by watering less often. Your plants won't be really smaller than optimum ones, but produce hotter fruit - and a very good root system (outdoors), which is important.
I have found the opposite to be true!
I grow my plants as optimally as I can - all my chinense (only very hot to superhots) in 20 liter nursery bags positioned under my lemon trees where they get morning sun - up to about 11:00 and then sun again from about 14:00.  They receive about 6 liters of water every second day.  The bags (black) are shielded against the sun by tall, rough grass that grows under the trees. 
My brother grows his plants in exactly the same bags, same soil.  His plants in the full sun the whole day, the bags get pretty hot.  He waters occasionally - maybe once or twice a week.
My plants are still growing and producing flowering branches, they are covered in 100's of fruit and it looks like they'll still be ripening in late March (basically the end of the season here).  His have stopped and almost all fruit ripe already.
So we tasted same cultivars from each of our grows (7 Pot Jonah, 7 Pot Red, CARDI Yellow Scorp, Douglah, Trini Scorp Butch T).   My fruits were significantly hotter.  When cut open they were covered in oil - colour dependent on cultivar - the yellows had yellow oil whereas the Douglah and Reds was more orange.  My fruits were almost bitter they were so loaded with oil.  His were sweeter and fruitier but not superhot.
He predicted his would be way hotter.  And he had to admit it was not the case.  Not that I grew them to be hotter - I just prefer the way the plants look when they healthy.
My reasoning as to why the Scenario 1 plants were hotter: capsaicin is an expensive thing for a plant to produce.  Oils are resource intensive.  Sugars are a lot more simple as they are basic products of photosynthesis.  In order to produce lots of this resource expensive compound the plant needs to be in a more optimal state.  More resources, at the right times and constantly = more capsaicin.
The whole idea does appear to have legs - look at the facility that grew THSC's ex-Guiness Record-holder.  The plants were grown under a canopy of taller trees to reduce heat stress, they were fertigated with AACT and voila!  Hotter fruits.
hello and sorry ROB my intention here is to not hijack your thread
but does the stress improve the flavor of the pods also??, i have often wondered about that one as i have never tried the stress experiment??
i know it works for onions and i think garlic, they do get hotter and seem to taste better too(i know there not related to peppers)
can anyone elaborate on this question??
i didn't wanna come off sounding like a smart :whistle: here i really am curious
i personally like flavor more than heat,i grow my personal favs based upon flavor not heat, i can take the heat but i figure why bother if it doesn't taste decent
 if the stress ups the heat it would be great if it elevated the sugar content and other flavors as well
DOES IT?? please let me know
thanks your friend Joe
What you say sounds logical, but it is logical the opposite way too; if the plant gets less water, it can produce less overall so it has to "defend" the pods more, so it becomes hotter (but less pods). Capsaicin meant to be a defensive mechanism so animals don't eat it. I did stress my plants last year, watered once a week in open ground, they wilted 1-2 days before but got plenty of water then. Huge plants, produced a lot of pods and flowered continuously. Watering less often but more is a good way to get a massive root system (in open ground mainly) , so it becomes more resistant to heat (and fungi because the top layer is usually dry), does not necessarily have to wait till wilt. Interesting topic :)
Hey Rob, you and your brother did, for lack of a better phrase, a two stimulus experiment.  The plants got dramatically different light AND water, so its hard to tell what specifically caused one plant to be hotter than another.
It would be interesting to see an experiment structured like this:
  • all plants grown from seeds of the same pod
  • all plants gown in the same geographical area
  • break water and sun requirements into a 2x2 matrix
  1. sun blocked from 11AM - 2PM, water every other day
  2. sun blocked from 11AM - 2PM, water once a week
  3. sun all day, water every other day
  4. sun all day, water once a week
I'd love to do something like this, but in Seattle I'll take as much sun as possible. 
Also, I'm also surprised that your brother's plants even survived growing in bags, taking that much sun (I assume its pretty hot in S Africa) and only being watered once a week.  I put my plants in 5 gallon black plastic pots and if they go 3 days without water they look terribly sad, and its not all that hot here.
Interesting stuff!
turbo said:
must be using a soil with lots of water retention / bad drainage?
I agree with turbo that you kinda miffed the experiment if you changed more than 1 variable.
I personally only "stress" my plants unintentionally lol. I forget to water a few days walk outside to see sad plants and go oh shit better waters these guys ASAP.
probably the amount of sun/strength of sun they get, semi-shaded plants put out much weaker peppers even though they're the same size and the plants are about as healthy
Stressing a plant might produce hotter pods, but you will probably get a small yield, maybe no yield, if the stress causes flower drop or increased susceptibility to disease. Not worth it IMO.
OK it was not an intentional experiment, I remarked that his plants were hideous and he replied that they would be way hotter than mine.  And so the fight started........
I understand the logic of producing less so therefore protecting them with more capsaicin.  The truth is those fruit are smaller and have less seed in them.  The reason: production is resource intensive.  Capsaicin is an expensive (resource intensive) compound to produce.  If you don't have the resources to produce large fruit filled with seeds you don't have the resources to produce a bumper load of capsaicin.  There are no wild plants that get remotely close to the capsaicin levels we have in domesticated, selected plants.  It is just too expensive to produce.  Much the same as proper wild game (not having access to supplementary feed such as corn or bean fields) will rarely if ever have the same level of fat as we see in animals that are domesticated and fed  premium under less stressed conditions (no predators, disease). 
If plants are water stressed during the final stages of maturation they will be sweeter.  Not because they produce more sugars under this regimen but rather because the sugars are more concentrated due to less moisture content.
All the plants are now in their second season in the same bag, same medium.To further compound the situation - all the plants were grown by my brother in the first year.  The bags stood in his veg garden surrounded by various veg and were quite sheltered.  So I think in their first year they developed really good root systems.
I must add that the idea behind this topic was to challenge the conventional thought that stressing plants makes them hotter (and not really about the actual grow).  I also thought so until I sampled my pods.  It makes biological sense that an organism is not going to waste what precious little resources it has on a luxury.  Rather the energy is used to first fulfill essential processes and thereafter what reproduction it can muster.
maybe if you stress the plant early (stunting pod size) then give it optimum conditions when it starts ripen (increase capascium production) would concentrate it the most..
I had a red trinidad scorpion that was a extra in a small 2 gallon container, that I stuck along side of a 4x6 board in a corner, we had some straight line winds that blew over the board knocking the plant and container over and pretty much crushed and split the main trunk and broke several stems. As I was Pretty Ill last season I just let the poor plant stay the way it was for most of the season, when I did take the board off the plant most of the trunk and stems had healed to a degree and it had flowered under the board and had made some small flattened pods that were pale colored compared to my other red Scorpions I tried eating half a pod from the stressed out plant to see how the small pods compared to some of the red trinidad scorpions that were watered and cared for. I can say the even though the small pods didn't taste as good,they were how ever much hotter than the plants that got plenty of water and full sunlight most of the time. I think that under conditions like that would produce hotter peppers as it mimics animals grazing on the plants forcing it to fight back by producing fewer but hotter pods to act as a deterrent.
I don't mean to hijack your post,  but I thought that this would fit in to what you were talking about.
All I can do is offer a theory.
If you were to grow plants regularly in good-to-great conditions. And instead of stressing them as they grow, only stress them once the fruit has started, then you will get a hotter pod.
The reason for this would be that the stonger the system, the better the utlilization of materials. If you have a huge trunk, huge vibrant root structure, and lots of nice broad leaves, then you would have the best possible factory available.
Once you have established the best possible scenario that particualr genetic will handle, and the plant goes to flower and the flowers are polinating and setting, THEN you stress the plant. You would be triggering the defensive capabilities of the plant, but it would have the best structure to do it with.
Analogy - Two men get a pimple, one man is a muscle bound freak, and the other is a tiny nerd. Nerd can pop zit, but muscle man DESTROYZIT!   :dance:  OK, not a great analogy, but it was funny in my head.
I was told that when you stress the plant, it goes into survival mode, this means that there will be a chemical imbalance in your plant, which will trigger this naturally occurring scenario which in turn starts to prematurly ripen pods, in turn would otherwise be still growing. A survival instinct to say the least, so the plant, and or plants have better chances of living on and creating viable seeds for reproduction, your plant will be more prone do diseases and all the bad voodoo also the soil will be dry inhibiting the ability of the roots to uptake the lifesourceof  your nutrients which may have a negative effect in the overall health of your plants. also, what I am thinking, now just a thought here, but there is probably less vitamins and minerals in a ripe stressed pod, so if you intend to make a sauce, the full maximum flavour will not be there.
But I am new to growing peppers, so if this sounds crazy dont listen to me lol
Environmental stress, particularly drought, has been found to statistically increase the heat level of hot peppers. It's also been found that peppers taken from the second node of the plant weigh more and are hotter than peppers taken from other nodes on the plant. Another rather interesting finding was that there didn't appear to be any decrease in productivity from hot peppers when it comes to drought. Decreased production was noticed in the mild varieties.

I'll post links to the research tomorrow.

I think it depends on a lot more than a watering schedule. To me it's the soil, what's in it and how good it is for the plant i.e., does it have in terns of nutrients what will keep them going. 
If you water less than usual to stress them I have found it to make the pods hotter when my soil has the correct nutrients in them. So that they will grab up as much of it as they can. Or if you're soil is not very good using a fert that has optimal calcium, magnesium, sulfur, and of course NPK ratio. But it seems to me that the micronutrients do much more for helping make a pepper hotter when you try to stress them. 
I used to stress red savina habs to try to make them even hotter back when they were the hottest in the world, my neighbor and I had four beds we tried it on, one bed had great coil in it that we had tested by our local college to get nutrient levels and it had an NPK ratio of something along the lines of 3-2-3, and the micronutrients I remember it had higher than normal calcium levels, sulfur levels, and magnesium levels. The other beds had the same soil but how we watered them was different. they were 5 x 5 x 12 raised beds.
Bed number one we watered the next day after we saw wilting, we would fertilize every 2 weeks with a regular fert as well as a supplemental cal, mag, sulfur fert.
Bed number two we watered the next day after we saw wilting, we would fertilize every 2 weeks with a regular fert with no supplemental micronutrients 
Bed number three we did sporadic watering ( from every 4 days to 3 days after wilting) and fertilizing sporadically with regular fertilizer and sporadic micronutrients
Bed number four we watered the next day after we saw wilting, but every once and a while would water 2-3 days after wilting, as well as fertilizer we would randomize between regular and regular plus supplemental. 
We kept a record of them the entire summer and fall to see what happened. 
In terms of heat it came in like this 
Bed number 1
Bed number 3
Bed number 4 
Bed number 2
The odd part is we found the pods from bed number 4 hotter when we would stress them (2 days after wilting, and adding supplemental ferts). So it seemed that when we stressed them and then allowed them to uptake a good amount of nutrients those pods would be hotter. 
This was all from our taste, so there was nothing ever sent off to get tested, just me and my 60 year old neighbor, so we couldn't get too scientific. But I can say that the pods from bed one were always hotter than any of the other ones, except for the pods from bed 4 on the stress plus supplemental ferts, they would match heat levels it seemed!
I was hoping to post something tonight, but as I dig deeper into the articles it appears that there are some rather large variances in findings. For the most part it would appear that any and all stress has an effect on the heat of a given pepper. Drought stress does affect the heat of a pepper, but dramatically more so in the mild to medium heat level peppers. While there was little to no change in productivity for drought stressed peppers, there was a decrease in productivity in the medium heat level peppers. It's kind of leaving me scratching my head. Basically what it comes down to is

genetics x environment = potential heat level... but it depends...

While I work on processing the information I'll post the links to the articles so others can have a look at them: