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Prawn Connery

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On the subject of the Bugbee UV trial, here are some direct quotes from the paper.
Regardless of the chemical profile, UV photons have not been shown to increase cannabinoids in high cannabinoid cultivars. The varieties 40 years ago contained around 3% cannabinoids, less than 20% of modern medical cannabis cultivars.
^ To say that cannabis 40 years ago only had 3% cannabinoids (that includes TOTAL cannabinoids, CBD and THC), is both ignorant and crazy. Testing methods in those days were not the same – they tested seeds, stalk and leaf in addition to flowers – and plants were not subject to the same quality controls as today's high-THC varietals.

This is, IMO, a poor excuse for using high-CBD instead of high-THC plants and then trying to justify the results in the context of medicinal cannabis (which wasn't tested).

It also shows up Bugbee's lack of experience wth cannabis. I'm growing a haze right now that is close to the landrace strains of the 70s and it has tested up to 20% THC. It is derived from Neville's Haze that was bred in the late 80s, early 90s.

I mean, I was there, smoking landrace pot in the early 80s imported directly from SE Asia, and there is no way that shit was 3% THC! Let alone the sativas we used to grow outdoors in Australia during the same time period.

Cannabinoids absorb UV photons, which may lead to degradation. It is possible that UV treated plants synthesized cannabinoids that were degraded by the high-energy UV photons, but it is difficult to draw conclusions from this study. In a separate study in our laboratory, we applied a UV-C (peak ~ 255 nm) dose of 0.01 mol m-2 (UV-PFD = 30 μmol m-2 s-1 for 300 sec) to dry flower that had been ground and spread in a thin layer. Cannabinoids declined by about 15% (unpublished data).
^ Smoking gun. Yes, UVB does degrade cannabinoids – we have tested and seen it.

Indeed, just 5 minutes (300 seconds) of UVC degraded cannabinoids by 15% according to Bugbee, so at least the elephant in the room was addressed.

5 minutes of 255nm = 15% reduction in cannabinoids. UVB is less powerful, but just imagine hours and hours of it!

There is potential that light sources with different wavelengths or ratios of UV-B and UV-A would lead to an increase in cannabinoids. Llewellyn et al. (2022) used a similar fluorescent UV-B/UV-A light that was used in this study. Rodriguez-Morrison et al. (2021) used narrow-band UV-B LEDs (peak 287 nm). Llewellyn et al. (2022) also demonstrated narrow-band UV-A LEDs (peak 385 nm) did not affect cannabinoid content. Studies from our own laboratory with 405 nm LEDs have confirmed this finding (unpublished data). Based on previous studies, neither UV-B nor UV-A significantly increase cannabinoids in high-cannabinoid cultivars.
Bugbee says 405nm doesn't work, but fails to include the methodology, if used in combination with UVB, then I can understand why. The amount of UVA exposure will also influence net cannabinoids. Our own tests using just 405nm show otherwise.


4.3 Relating UV treatments to sunlight in the field​

A common criticism of research on UV in controlled environments is that the conditions do not adequately reflect the field (Caldwell et al., 1994). The maximum PPFD from sunlight on a clear day in the middle of summer is about 2000 μmol m-2 s-1. The UV-B PFD is about 7 μmol m-2 s-1 and the UV-A PFD is about 160 μmol m-2 s-1 (Caldwell et al., 1994). In this study, UV-B PFD was about 6 μmol m-2 s-1, but the UV-A PFD was only about 4 μmol m-2 s-1. Previous studies used UV-B PFDs ranging from 0.01 to 1.6 μmol m-2 s-1 and little (Llewellyn et al., 2022) to no UV-A (Rodriguez-Morrison et al., 2021).
Just 4 umol/m2/s of UVA. They also used a ratio of 1.5 UVB to 1.0 UVA PFD, although the amount of energy in the UVB was even higher than this ratio.

The point is there are a lot of holes to pick in this study for those who know what they're looking at.
 

dogzter

Drapetomaniac
Not trying to be a dick your garden is lovely.
What makes led flowers look like this?
I see this look a lot and wonder why it is.
Doesn't look normal or particularly healthy am I missing something?
 

weedemart

Well-known member
Not trying to be a dick your garden is lovely.
What makes led flowers look like this?
I see this look a lot and wonder why it is.
Doesn't look normal or particularly healthy am I missing something?
If you are talking about the foxtails it can be genetics or environnement but it looks like genetics.

Foxtailing is a sought-after genetic trait. Much like resinous males, it is associated with a higher than average THC potential.

But sometimes foxtailing is the result of too much stress.Too hot or too fed. I dont think it's the case.
 

Crooked8

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If you are talking about the foxtails it can be genetics or environnement but it looks like genetics.

Foxtailing is a sought-after genetic trait. Much like resinous males, it is associated with a higher than average THC potential.

But sometimes foxtailing is the result of too much stress.Too hot or too fed. I dont think it's the case.
I dunno about sought after, if youre washing there is more surface area for trichomes. As far as marketability as flower people complain about it. Often its out of ignorance but nonetheless, people prefer denser and rounder morphology as a general whole. Those flowers look great though imo id love to smoke it.
 

weedemart

Well-known member
I dunno about sought after, if youre washing there is more surface area for trichomes. As far as marketability as flower people complain about it. Often its out of ignorance but nonetheless, people prefer denser and rounder morphology as a general whole. Those flowers look great though imo id love to smoke it.
Exactly it offer more surface area for trichomes.

It a genetics trait used to breed.
 

weedemart

Well-known member
Breeders are typically trying to avoid foxtailing, unless its to wash/extract. Im definitely not looking for it in our program.
Depend on breeder goals.

The extract market is growing and there is demand from processors for the material. Genetic foxtailing does not harm floral quality or harvest, it is just undesirable for some because of aesthetics but there are plenty of advantages to this trait in cultivation, especially when it comes to processing and extracts.
 

Crooked8

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Depend on breeder goals.

The extract market is growing and there is demand from processors for the material. Genetic foxtailing does not harm floral quality or harvest, it is just undesirable for some because of aesthetics but there are plenty of advantages to this trait in cultivation, especially when it comes to processing and extracts.
You basically reworded what i just said but thats fine haha
 

DARKSIDER

Official Seed Tester
Moderator
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I dunno about sought after, if youre washing there is more surface area for trichomes. As far as marketability as flower people complain about it. Often its out of ignorance but nonetheless, people prefer denser and rounder morphology as a general whole. Those flowers look great though imo id love to smoke it.
And you would be more than welcome to smoke them Crooked8 :thank you::tiphat:
 

wh1p3dm34t

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Supermod
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sorry for my ignorance, and off topic question, but to make extracts, isn t better to use a hashplant type cultivar, with all over resin production, and not to focus on calyxes?

wire-2024-02-26-at-06-32-47-jpg.18965112
wire-2024-02-26-at-06-32-44-jpg.18965111

wire-2024-02-26-at-06-32-41-jpg.18965113
 

weedemart

Well-known member
sorry for my ignorance, and off topic question, but to make extracts, isn t better to use a hashplant type cultivar, with all over resin production, and not to focus on calyxes?

wire-2024-02-26-at-06-32-47-jpg.18965112
wire-2024-02-26-at-06-32-44-jpg.18965111

wire-2024-02-26-at-06-32-41-jpg.18965113

Depend on the breeder priority. Foxtailing genetics are more prone to extract because they usually produce more material for the processor and they are harder to trims so they just skip the trimming part and grind everything. Lot of genetics have foxtailing heritage and some breeder just keep passing this particular trait. dr.grinspoon for example. But yeah terpenes will always be number one trait after sexual stability , for me. It really depend what the breeder wants in his gene pool.

If you ask me which trait will be the most beneficial for extract , I would probly answer foxtailing genetics. They just bleed trichomes. I had very resinous genetics and they were not as good as some foxtailing genetics for hash making. The yield was not there.

And the fact that foxtailing genetics will most likely end in extract, they are really great at producing high yield of trichomes even if you give up some floral qualities, it doesnt matter.

Actually they make more money off extract than buds in the legal market!

This list comes from Mr.Soul, in order of importance.
  1. Resistance to hermaphrodism
  2. Vigor/Yield
  3. Potency
  4. Flavor
  5. Rate of flowering response
  6. Resin production
  7. Stature
  8. Scent
  9. Floral structure
  10. Floral color
 
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wh1p3dm34t

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that list is not set in stone, everyone has different priorities.

my question was more simple than the answer, i was not talking about breeders goal.

i put it into more simple,
you have 2 strains, one is a resinmonster all over its surface, ready to harvest in 45-60 days, depending on growing method, and personal preference of ripeness,
and you have another one totally different growing habits, more calyxes, longer flowering time 60-80 for example.
looks somthing like this.:
image_attachment-4-jpg.18965270
image_attachment-8-jpg.18965274


so i would think that, with leds i would choose the first mentioned strain to make extracts of any kind..
 

weedemart

Well-known member
that list is not set in stone, everyone has different priorities.

my question was more simple than the answer, i was not talking about breeders goal.

i put it into more simple,
you have 2 strains, one is a resinmonster all over its surface, ready to harvest in 45-60 days, depending on growing method, and personal preference of ripeness,
and you have another one totally different growing habits, more calyxes, longer flowering time 60-80 for example.
looks somthing like this.:
image_attachment-4-jpg.18965270
image_attachment-8-jpg.18965274


so i would think that, with leds i would choose the first mentioned strain to make extracts of any kind

What you talking about is bag appeal.not linked with potency/resin production. The times it take to harvest is not significant to me as longer the flowering time usually higher the yield

Resin production is not what you see, it's the yield of trichomes per mass of dry flower. Same for potency cannabinoids per mass of dry flower. Sometimes it looks frosty but the yield/potency is not there

To be clear the most important trait for extract is a strain that produce high yield of trichomes per dry mass and usually the fluffly pheno yield more than compact round buds.

Potency is overrated
 

weedemart

Well-known member
And all this comes from a guy who made his own kief for over 15yrs with hundred of strains

Some strains are better than other for extract
 

Prawn Connery

Licence To Krill
Vendor
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The times it take to harvest is not significant to me as longer the flowering time usually higher the yield
For any given strain, there is a direct correlation between light intensity, canopy area and yield, so longer flowering strains can take up valuable light and space while their canopies are filling in compared to shorter flowering strains that fill the area faster.

With short-flowering strains, you either start with more plants or bigger plants when you turn them, at which point they are using up more of the grow area and light than a long-flowering plant that starts off smaller or fewer in number, because they need more time to fill up the same area.

That's a waste of light and space, unless you lower and dim your lights – and if you do lower and dim your lights, then you are not maximising the space available.

You can stagger your grow so that the faster plants fill the canopy area and finish while the slower plants are still growing, but the grow area will fuller for more of the time and can use more of the light wqhe you fill it with fast-finishing varieties.

If you can fit 3x 8-week harvests into the same time-frame as 2x 12-week harvests, that means you are filling the grow area 1.5x as often. You might think you are getting a bigger harvest from the long-flowering plants, but as soon as they run out of canopy space, they get too dense and yields suffer.
 

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