HOW HIGH IS "HIGHLAND"?

[Psychosativa]

Hi Vini

This is what Ed Rosenthal wrote in Cannabis Cullture

"A researcher conducted a controlled experiment in a greenhouse. He lit a group of high potency plants similarly except with the addition of UVB light to some groups. He found that the percentage of THC increased in a direct ratio with the increase in UVB light. This research confirms the adage that high altitude plants are more potent than those grown at low altitudes".

 

[clowntown]

It'd be nice to see someone do a T5-style grow with a tanning bed light.

 

[ixnay007]

One of the nice things about CMH bulbs is they output more UVB than HPS, so that makes a nice addition to the full spectrum light they have.

 

[ixnay007]

Rosy & Ixnay

It really makes sense what you're saying.

In the other hand, it's true that sativas have certain distinctive chemotypes, and one would think that environmental factors have incided in the evolution of these chemotypes.
Probably the UVB-thing is just a sketchy idea which has not been developed into a serious experiment, but It would be fantastic to find an explanation on the adaptative reasons for sativas' chemotypes.

My intuition tells me tropics are more conductive to sativa dominant crosses, so I'm gonna try them beside some indicas, just to be sure.

Thanks, I've learned a lot from your inputs

Without a doubt sativas are more adapted to the tropics, you need only look and see what grows there as landraces.

Apart from the fact their "airy" buds ensure less mold problems in the high humidity of the tropics, and their thinner leaves make them less succeptible to heavy rains, the fact that they can flower for 20+ weeks makes them suitable only for places where the annual temperature does not vary tons between the winter and the summer.

You may have problems with indicas PS, as they are a lot more sensitive to photoperiods than sativas (some hazes won't flower outdoors until it is truly 12/12... 12.5 11.5 won't) so putting them outdoors means that a lot of them will flower as soon as they reach maturity.

 

[Rosy Cheeks]

One of the nice things about CMH bulbs is they output more UVB than HPS, so that makes a nice addition to the full spectrum light they have.

They may produce more radiation in the 320 to 280 nm range, but most bulbs on the market - whether it's MH, Xenon, fluorescents or CMH - comes with a UV filter (generally a titanium film coating the quartz, similar to what you find in sunglasses) in order to pass safety regulations concerning UV-B (which is dangerous radiation after all). The exception to this are so called reptile lights and perhaps tanning lights.

The result is that these bulbs emit only insignifically more UV-B that for instance an HPS bulb.

 

[Kenny Lingus]

hmmmm?!

hmmmm?!

I don't know what to think...
Cannabis sativa Linné is believed to have evolved into medicinal plants in the sense of potent THC producers. It probably developed naturally around the equator, but has been maintained , replicated and improved elsewhere for ages.

Maybe some manipulation can be done to alter the THC levels, but the safer bet is to just grow healthy plants in heaps and select the better ones as you go. Simply put: breeding!

If I should manipulate my grows to increase the THC-return I'd definitively put my investments into proven techniques first. -I'd take a look at water/nutrient management, CO2-boost, drop/diff (temperature control) firstly, air-pressure, and then maybe some far red trials to force extra branching and flowering spots....
I think the air pressure and drier air with cool nights in elevated areas are of more significance than any possible increase of UV-radiation. Maybe the presence of different red wavelengths at sunset/sunrise too. (PS! In deserts, snow and at the seaside you will have even more UV-bombardment...-although you don't find too much growing there because of them other limiting factors.)

I even think I read that tests conclude with light (possibly UV-rays) are a main cause in the degradation of THC in processed plant matter. So why should it be so beneficial in vitro???

 

[Rosy Cheeks]

Hey Kenny, long time no see.

It's not clear to me whether you propose that Cannabis Sativa or THC as a substance developed around the equator.

I can tell you with certainty that Cannabis Sativa did not develop around the equator. Cannabis is - as a species - a short day plant, meaning that it uses the change in seasons and light conditions to trigger flowering. The flowering process is not activated by light, but darkness. This means that Cannabis originated in a temperate zone, where - in the autumn - days grow shorter and nights longer. Since most varieties flower around 10 hours of uninterrupted darkness, it must have developed a fair bit away from the equatorial region, where light conditions stay mostly the same year around. Botanists believe its origins to be found somewhere in the Himalayan region, or Asia Minor (possibly China).

Secondly, Cannabis is an annuary plant, meaning that it germinates, grows, flowers and dies in a year cycle, and that too is tied in with the seasons. It germinates in spring, grows in the summer, flowers in end summer/autumn and dies in end autumn/winter. Cannabis does not like cold (but can deal with it better than most people think), which is why it does not survive the winter. Had Cannabis evolved around the equator, where it rarely gets cold enough to even bother the plant, it would not need to end its life in the winter, but could go on living around the year, for years and years, as trees do.

The fact that Cannabis has invested and thrives in tropical regions only shows that it is a highly adaptable species, and the hot and wet conditions that reigns in these parts of the world suits it.

THC could have evolved in the equatorial zone, but temperate zone plants generally aren't less potent than tropical zone plants. Rather, the Cannabinoid ratios are different, creating different types of psychoactive effects. I wouldn't bet on that theory, but it's possible.

As a sidenote on tropical climates, you could say that it's good for the plant and less good for the THC. It's something of a paradox that while the plant loves light, THC degrades from it. THC also starts to degrade in temperatures above 32º (89.6F), which means that if the THC in a tropical plant degrades faster than in a temperate zone plant, and the plant needs it in order to protect itself (against herbivores, insects, UV-B or whatever the THC is there for), then it will have to produce higher amounts of it, in order to replace it. This is theoretical though, and a lot more research needs to be done in this area before we understand the process of THC.

 

[clowntown]

Don't those reptile lights output more UVA than UVB?

 

[ixnay007]

Rosy, the fact that high temps destroy THC might account for why mountain grown tropical sativas are more potent, temperatures in mountainous areas are always lower, but the light is often more intense... so the plant won't be losing THC to high temps, and it will be producing more trichomes to protect against cold/UV-b, etc etc..

 

[Kenny Lingus]

Hey Kenny, long time no see.

It's not clear to me whether you propose that Cannabis Sativa or THC as a substance developed around the equator.
.

Hei Rosy!

Actually I propose none, but I just refer to a weed world article (and from the world of cannabis posters) that hemp for drug use was first evident after plants had been acclimatized to more equatorial regions in India/s.e. asia.

Although those articles do claim a lot of bollocks according other stuff too, so it should probably be taken with a few pinches of salt over the right shoulder...

If resin/thc is insect repelling I may understand why they had to be enforced in tropical areas as there's so many creepy crawlies down there year round.

 

[xet]

Highlands typically range from 300m-600m while the highlands of Afghanistan and Sri Lanka are at 2000-3000m. https://en.wikipedia.org/wiki/Highland

Australia for example does not have it's highlands start until 500m.

 

[Montuno]

You should try the more sativa the better, if you want production.
At your latitude, indicas are dwarfed.
Don't worry so much about altitude, type of solar radiation... You can live on top of the world, but if you don't have good genetics and a good hand at growing...
Best of luck, and good health to enjoy it.