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misc Scientific Observations of Environmental Stress on Pepper Varieties

I'm around a half a mile above sea level and not particularly far from the 45th parallel.

The low last night was near 20℉
It was the first hard freeze of the season.
I harvested a couple dozen green fruits and took several cuttings yesterday before the cold hit.

It would be interesting to test the impact of cool temperatures upon enzyme rates related to capsaicin biosynthesis.

I also expect that before long Capsicum will be identified with significant capsaicin content in the leaf.
 
This is all neat. Thought it was a great idea way a while ago when I started.

Even if its true what would be the practicality of it?

Crap, it was stressful as a grower purposely stressing my plants. So much easier to choose or breed a var to your prefered heat, and grow it happy, no?

Im in canada. The late season (Nov...as low as a light frost) chillies I harvest are just as hot as the first to turn in the heat of Aug (high 20s mid 30s). My supers, again way back... was gardenless for 6yrs saving for home... were as drippy with oil as any youtubes or detailed member photo i compared to.

There may be a bit of difference. Were it holy shit night to day different there would be simple, comparable, easy and repeatable results. And all the chileheads would consider it gospel. I dunno. Super interesting just not very useful for growing, imo.
 
AaronB said:
1.) Thought it was a great idea way a while ago when I started.

Even if its true what would be the practicality of it?

Crap, it was stressful as a grower purposely stressing my plants. So much easier to choose or breed a var to your prefered heat, and grow it happy, no?

Im in canada. The late season (Nov...as low as a light frost) chillies I harvest are just as hot as the first to turn in the heat of Aug (high 20s mid 30s). My supers, again way back... was gardenless for 6yrs saving for home... were as drippy with oil as any youtubes or detailed member photo i compared to.

There may be a bit of difference. Were it holy shit night to day different there would be simple, comparable, easy and repeatable results. And all the chileheads would consider it gospel. I dunno. 2.) Super interesting just not very useful for growing, imo.
 
1. It was bantered about back aways:

Sept. 2008_Stressing Plants
Feb. 2012_Stressing Out a Plant
June 2012_Stressing peppers
July 2014_The ins and outs of stressing peppers.
Jan. 2015_Stressing for heat
Sept. 2016_Plant stressing techniques
 
 
2.   Title reads:
 
Scientific Observations of Environmental Stress on Pepper Varieties
 
Nothing in there purports as to growing techniques.
 
Did i not share my personal observations?

My, modestly home scientific grows where i enjoy comparing all sorts of things, led me to observe, in a small sample of like varieties, no humanly noticeable increase in capsaicin on my personal tongue, when i stressed the shit outta some after reading things here and thinking hey this might be a great finding that applies to me, perhaps.

Same with cooler temps.

:) just sharing my own personal observations, in my cold northern climate.
 
Ill add, and I believe another member mentioned that any legitimate evolutionary correlations kind of become a moot point when we are observing a trait that has been totally and completly changed by human breeding programs over thousands of years.

How does it make sense that stress is a factor, or natural plant protections etc. When it was us humans that took the chemical we enjoyed and supersized it through unnatural selection?

I think thats a fair question related to 'your' topic. No?

My bet, from my armchair: genes + resource management dictate heat. Ability to build + pieces to build it.
 
I found the following interesting:
 
Behavior of the Hottest Chili Peppers in the World Cultivated in Yucatan, Mexico
Liliana S. Muñoz-Ramírez e.a.
HortScience 53(12) 2018 p.1772-1775
 
DOI: 10.21273/HORTSCI13574-18
 
Abstract: The Yucatan Peninsula is recognized as the center of genetic diversity of Habanero peppers (Capsicum chinense Jacq.), which can be distinguished from those cultivated in other regions of the world by their aroma, taste, and—most of all—by their pungency. We evaluated three commercial varieties of chili peppers reported as being the hottest in the world: ‘Bhut Jolokia’, ‘Trinidad Moruga Scorpion’, and ‘Carolina Reaper’. The aim of our study was to determine the behavior of the pungency when cultivated under the edaphoclimatic conditions of Yucatan. Our results show that the three varieties registered greater contents in comparison with those reported in other regions of the world. ‘Carolina Reaper’—considered to be the hottest variety in the world, with a pungency of 2,200,000 Scoville heat units (SHU)—when cultivated in Yucatan, had a pungency of 3,006,330 SHU, which was greater than all the other varieties analyzed.
 
Complete article available online.
 
Yucatan climate charts.
 
My climate is comparable, though temperatures in April-May usually don't go beyond 37°C (in Yucatan they can rise to 40°C+), and we have a three-to-four times higher annual precipitation which, however, falls with the same annual distribution pattern. Makes me thinking of sending some peppers in the future for analysis...
 
Wow, carolina reaper 3M SHU? That it impressive. But look at the Bhut Jolokia... Almost double increase in capsaicinoids. Boys and girls we have some serious data here :)

‘Bhut Jolokia’ has been considered one of the most pungent chili varieties in the world, although this characteristic has shown a high variation depending on the region where it is cultivated. Mathur et al. (2000), in a study conducted with this variety in India, reported a pungency of 855,000 SHU, whereas Bosland and Baral (2007) reported 1,001,304 SHU when it was grown in New Mexico, which allowed them to record it in the Guinness Book of World Records as the most spicy variety in the world, displacing ‘Red Savina’ (577,000 SHU). Subsequently, Islam et al. (2015) evaluated the content of capsaicinoids in 92 accessions of ‘Bhut Jolokia’ collections in northwestern India. They found high variability, with a range of 11.95 to 72.05 mg·g–1 DW and a pungency of 191,135 to 1,152,832 SHU. In our study, the content of capsaicinoids registered for ‘Bhut Jolokia’ was 120.38 mg·g–1 DW, which corresponds to a pungency of 1,938,089 SHU
 
Different studies, different results and still so many things that are yet to be discovered! Great datas to understand the influence of growing conditions/parameters but at our scale, does it really makes a noticeable difference?? Past a certain point (when my face is melting!) I certainly could not tell you which pods has more SHU (let's say between 1.2 million and 1.4 million SHU for example)🤷‍♂️

Also, I noticed that capsaicin compounds seems to vary a lot and sometimes, a strain with lower SHU will hit me way harder that another one rated higher. Just to add to this discussion, here's 2 other factors that are known to affect the cap content:
Studies_Caps.JPG
 
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Any advice on how I should proceed? I have started with a 1:1 ratio. One part organic and another part mineral. My organic fertilizer is dry and it's a Neudorff berry. Also I add some seaweed to it. I use ~1 EC solution. Mineral fertilizer is GHE Gro/Micro/Bloom, I use 1:1:1 ratio. I'm giving this to Mojo Scoundrels.
 
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