Adding UVB spectrum to COBs - opinions on this setup?

Y

yosim

Well-Known Member
Airwalker16 said:
See. They kick ass. Just watch this.
I know KindLED are some shady muthafuggas, but these results are pretty self determined.
Click to expand...
cool yeah, as suspected no UVB on the standard LED setup

Agromax saying in effect then that 64uw/cm2 is a safe limit for amount of UVB if they recommend a distance of 4 feet - are you running these agromax lights, do you have them on normal lighting schedule?
thanks
 
S

Shugglet

Well-Known Member
Airwalker16 said:
See. They kick ass. Just watch this.
I know KindLED are some shady muthafuggas, but these results are pretty self determined.
Click to expand...
Itd be cool if they did a video comparing actual crop differences rather than showing that they simply do in fact put out uv light lol.
 
Airwalker16

Airwalker16

Well-Known Member
I haven't ran them personally no. But all I can say, is if you want to use uvb supplementation, this is how you do it.
 
Abiqua

Abiqua

Well-Known Member
Since uvb is never static in sunlight itself, my belief is that you need little to none.

Why do non UVB cob flowers always get the raves?

In fact, so little is known about positive benefits of UV light versus the actual downside, we tend to be dismissive to say the least.

UVB was shown to increase certain terpenoids, not in cannabis, and then correlated to say as much...yeah Right. Most data seems to show a damage factor around every bend. Mechoulam proved that THC alone, doesn't get you high. So what is uV and uvb spectrums doing to the other 99 or so cannibinoids, flavonols and terps, that we have no clue about?

The UV thing is way over played with such little data :peace:
 
Y

yosim

Well-Known Member
Abiqua said:
Since uvb is never static in sunlight itself, my belief is that you need little to none.

Why do non UVB cob flowers always get the raves?

In fact, so little is known about positive benefits of UV light versus the actual downside, we tend to be dismissive to say the least.

UVB was shown to increase certain terpenoids, not in cannabis, and then correlated to say as much...yeah Right. Most data seems to show a damage factor around every bend. Mechoulam proved that THC alone, doesn't get you high. So what is uV and uvb spectrums doing to the other 99 or so cannibinoids, flavonols and terps, that we have no clue about?

The UV thing is way over played with such little data :peace:
Click to expand...

some info here http://www.stonerhaven.com/topic/1276-uv-a-uv-b-rays-and-there-possible-effects-on-growing-marijuana/page-1

what do you mean when you say "Since uvb is never static in sunlight itself" ?
 
Abiqua

Abiqua

Well-Known Member
Show me better research than stoner haven, sorry.

Mint [lamiaciaea] was found to have UV-b absorbing flavonols in presence of certain compounds. That would put a huge bummer on UV-b uptake if cannabis might have similar reactions, no?
 
Y

yosim

Well-Known Member
Abiqua said:
Show me better research than stoner haven, sorry.
Click to expand...
theres a paper listed there on that link but the link is dead now, however the quoted article remains, its about half way down on page 1
Review
The effect of ultraviolet radiation on the accumulation of medicinal
compounds in plants
Wen Jing Zhang a,b, Lars Olof Björn a,c,⁎
 
Abiqua

Abiqua

Well-Known Member
yosim said:
theres a paper listed there on that link but the link is dead now, however the quoted article remains, its about half way down on page 1
Review
The effect of ultraviolet radiation on the accumulation of medicinal
compounds in plants
Wen Jing Zhang a,b, Lars Olof Björn a,c,⁎
Click to expand...
Can you post the study in full? What plants, what was the outcome?
I posted a few links too, I have hundreds though....UV is great area of study, although, most if not all of the claims made, seem to lack some serious methodology....imho
 
Abiqua

Abiqua

Well-Known Member
yosim said:
theres a paper listed there on that link but the link is dead now, however the quoted article remains, its about half way down on page 1
Review
The effect of ultraviolet radiation on the accumulation of medicinal
compounds in plants
Wen Jing Zhang a,b, Lars Olof Björn a,c,⁎
Click to expand...
actually can you post the ROI and I will look it up on SciHub......
 
Y

yosim

Well-Known Member
Abiqua said:
Can you post the study in full? What plants, what was the outcome?
I posted a few links too, I have hundreds though....UV is great area of study, although, most if not all of the claims made, seem to lack some serious methodology....imho
Click to expand...
I will quote whats there below - doesnt appear to be the full report but as i said the link to original article is dead unfortunately

The effect of ultraviolet radiation on the accumulation of medicinal
compounds in plants
Wen Jing Zhang a,b, Lars Olof Björn a,c,⁎
a Lund University, Department of Cell and Organism Biology, Sölvegatan 35, SE-22362 Lund, Sweden
b QingHai Normal University, Key Laboratory of Resources and Environment in Qinghai-Tibet Plateau, Ministry of Education, Qinghai 810008, China
c Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education, School of Life Science, South China Normal University, Guangzhou 510631, China


Essential oils and terpenoids
Essential oils constitute a heterogeneous collection of
chemical compounds. They have in common that they are
synthesized by plants and are volatile and mostly soluble in
ethanol. They have traditionally been obtained from plants
by extraction and distillation. Since the middle ages, they
have been widely used for insecticidal, medicinal and cosmetic
purposes. For a detailed review of their biological effects
the reader is referred to Bakkali et al. [80]. Schelz et al.
[81] have assayed antimicrobial effects of several of them.
Some essential oil compounds are terpenoids, i.e. a class of
hydrocarbons and derivatives of them. The substances from
Glycyrrhiza and yew dealt with at the end of this section are
also terpenoids.
Karousou et al. [82] studied two different chemotypes of
Mentha spicata, and found that in one of them UV-B radiation,
on a dry weight basis, caused a 50% increase in essential oil
production, while in the other chemotype the increase was
insignificant.
A more thorough investigationwas carried out by Johnson
et al. [22] on essential oil production in sweet basil (Ocimum
basilicum L.), in which the effect of ultraviolet radiation is
much greater. They separately analyzed no less than 22 different
essential oil compounds in this plant. The effect of
UV-B radiation increased with the age of the plants, and was
different for different compounds, but mostly positive. At
the 5 leaf stage the irradiated plants contained between 3
and 4 times as much of most essential oil components as did
the unirradiated control plants. In a later paper [83] by the
same group, the authors reported that UV-B radiation is
necessary for normal development of oil glands in sweet
basil. There seems to be a requirement for UV-B in the filling
of the glandular trichomes of this plant.


Cannabinoids
Pate [95] cites older literature suggesting that UV-B radiation
promotes cannaboid production in Cannabis and also
speculates about cannaboid evolution. Plots of estimated UV-B
exposure in different growth places shows an increase in Δ9-
tetrahydrocannabinol (Δ9-THC) with exposure, but a decrease
in cannabidiol. Lydon [96] and Lydon et al.[97] found that in
both leaf and floral tissues the concentration of Δ9-THC but not
of other cannabinoids increased linearly with UV-B exposure
in drug-type Cannabis sativa plants (Fig. 7), but not in fibertype
plants of the same species. Nowadays many sites on the
Internet show that the dependency of cannabinol accumulation
on UV-B radiation is common knowledge among private
entrepreneurs in the drug industry. The biosynthetic pathway
of cannabinoid synthesis is shown in Fig. 8.
It is not known which enzyme or enzymes for Δ9-
tetrahydrocannabinol biosynthesis are induced or stimulated
by UV-B radiation, but one can speculate. The gene for polyketide
synthase catalyzing the synthesis of olivetolic acid
possesses strong sequence homology with chalcone synthase
and may have evolved from this. Chalcone synthase is one of
the classic UV-B-regulated enzymes.


Conclusion
We have seen that the contents of medicinal substances of
many kinds in many plants are increased by exposure to
ultraviolet radiation, and in particular UV-B radiation. This
effect is not always regarded as a stress phenomenon, as in
many cases the increase in the secondary metabolites can be
achieved by radiation so low that they do not negatively affect
growth, and do not result in any visible damage. Thus, in order
to make the production of medicinal plant substances efficient,
it may be advisable to try exposure to ultraviolet radiation
also in cases which have not yet been investigated. I some cases UV-A or UV-C radiation may be more suitable
than UV-B.
Click to expand...
 
RM3

RM3

Well-Known Member
Shugglet said:
Itd be cool if they did a video comparing actual crop differences rather than showing that they simply do in fact put out uv light lol.
Click to expand...
minimum 36 inches from canopy and 15 minute spurts in the middle 4 hours of flower

take it seriously !!!!!!! these bulbs are extreme !!!! Rig it so you can turn em off when in the garden ! I got blisters on my back from less than 30 seconds at 8 inches when I leaned in to look at a bud while they were on
 
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