increasing resin production with UV

[the gnome]

I was reading about UV stimultating resin production.
I read where a member here did a grow with UV flouros on the sides of is HID hoods, can't member is name? but he was under the impression it helps.

years ago a canadian bud of mine said he used metal halide in flower and had the stickiests buds because of the UV in the MH.
said he got more weight and such with hps but the stickie buds came from buds flowered under mh

would it be reasonable to run MH instead of HPS the last few weeks of flower to get the plants to ooze a bit or mabe an appreciable amount more of the good stuff? do the plants really need the red wavel length any more at this point?
I haven't seen a lot of talk about UV.

 

[VerdantGreen]

one guys who uses UV is strainbrain. i fitted some UV tubes in my last grow but hard to say what difference it made this soon. MH has much more UV than HPS and some people do use MH for flower. i think i read a dj short article that says he used MH for late flower.

 

[the gnome]

yeah, strainbrain is the name of the poster with the uv side lamps on his HIDs
thx verdant
sounds like the a goodidea of hitting the girls up with some xtra uv in the last few weeks.
I think about the indica's that are known for heavy resin output for hash production and the majority seem to be in higher altitudes, foothills and mountains where UV is much
more intense.
Ive yet to find the conclusive data that proves it but its thought that higher UV= higher resin/trichome production.

 

[shawkmon]

i remember reading its the lizard light from petsmart i think had all the uv to add the extra resin, anyway, i think there is something to this, anything to get more like the sun

 

[wantaknow]

i have a 3 k set up and 1 lamp is mh ,for a mixed specturm,i get better lenier growth,and a stoney product,i dont have a killer cut to work with atm ,i am running ppp by dp

 

[TRONIC187]

MH in late late flower has always worked great for this guy

 

[igrowone]

i've only read about this method, but very interested
i recall one post that seemed to say there were some strains that benefit more from the extra UV
tropical strains and highland strains were mentioned i think, which seems to make a certain sense

 

[localman]

Higher ELEVATION = HIGHER RESIN = HIGHER ME

 

[Pinball Wizard]

I like to 'tan the trichs' with 2 400 watt CMH bulbs...

 

[the gnome]

time bust out the MH bulbs back out

 

[Pinball Wizard]

does anyone know if UV varies according to the kelvin temp of MH bulbs?

would 3000k be the same UV as 6500k...????

 

[VerdantGreen]

given that UV is at the blue end then it makes sense that the 6500 would have more.

not certain though

 

[Yankee Grower]

Higher ELEVATION = HIGHER RESIN = HIGHER ME

Yes I remember a Swiss study which showed that lower elevation grown weed yielded better but higher elevation grown weed had a higher THC content. I've had the same cut grown the same way at 2,500' and 5,000' feet and noticeable difference to me and my buddy between the 2 with the high elevation stuff almost like a different strain.

 

[J4F]

Take a look at this https://www.icmag.com/ic/showthread.php?t=93829

 

[LastWaltz]

Ultraviolet Light

Different colors of light have different wavelength frequencies. The lower the frequency, the more radiation the light emits. Ultraviolet light has low wavelength frequencies. Ultraviolet rays are produced by the sun and are invisible to the naked human eye.

Positive Effects of UV Light on Plants

UV light assists in directing the architectural growth of a plant. It does this by eradicating or limiting certain hormones in the plant. UV light also boosts the plant's immunity to pests and harmful bacteria.

Negative Effects of UV Light on Plants

The lower frequencies of UV light will cause severe radiation poisoning within the plant, resulting in loss of color, stunted or deformed growth or death. The Finnish Meteorological Institute says the ozone layer protects life on Earth from excessive UV radiation.

Effects of Blocking UV on Plants

In 2009, Diane L. Polyakov submitted a project to the California State Science Fair showing the effects of UV light on pea plants. The conclusion showed that blocking UV light does help the plant to grow, but also deprives the plant of essential nutrients used to combat mold.

Reduction of Leaf Size

The leaves of plants receiving UV light are usually smaller than those in normal sunlight.
While information about the effects of ultraviolet (UV) light on plants is limited, there is evidence that plants exposed to excessive UV radiation will have smaller leaves than those exposed to normal sunlight. As a result such plants have less surface area to absorb solar energy leading to decreased photosynthesis, which then has further impact on their growth. In a way, this acts as a positive feedback cycle.

Decrease in Plant Height

Plants exposed to ultraviolet (UV) light in large quantities are also unlikely to grow as tall as plants not exposed to UV. This is believed to be in part because, owing to their smaller leaf size, they are unable to absorb as much energy as plants not exposed to UV light. Plants exposed to UV light also experience leaf curling, which reduces their size by preventing leaves from growing as high or as long as those exposed to normal sunlight.

Shortened Stem Length

The stems of plants exposed to UV light are often shorter than those growing in more normal conditions.
Plants exposed to UV light may have shorter stems than those allowed to grow under normal conditions. With some plant varieties, this might be considered a good thing, such as plants for garden beds. In other cases, it is not necessarily beneficial, such as with forage crops and other agricultural products. Not all plants experience shortened stem growth; this effect varies from species to species.

Damage to DNA

Some scientific evidence suggests that exposing plants to ultraviolet light in large quantities may damage their DNA and cause mutations. This can have a number of corresponding effects on plant growth and the reproductive integrity of future generations grown from the seeds of plants exposed to ultraviolet light. These effects differ somewhat, according to the species of plant used and the type of ultraviolet light it is exposed to.

Crops

Scientists have been testing the effects of ultraviolet-B radiation on crops for decades due to concerns about the depletion of the ozone layer. Although the effects vary among plant species and cultivars, most plants are negatively affected to some degree.

 

[GrinStick]

isn't the purpose of the trichomes to diffuse bright light to protect the leaf surface?
if that is the case, more UV (in limited amounts) could stimulate trichome production, but imagine it would have to be earlier in flower, than late(speculating).
prismatic effect of the stalked capitate trichomes could be to seperate the spectrum of light, or to spread it over a greater surface area. haven't asked my girls which one it is yet though.
could be a mechanism to speed decarboxalation, could be just me...

 

[LastWaltz]

Effects of UV Irradiation on Photosynthesis

Cells are especially prone to photo-inhibition during an increase in phtot irradiance. It has been shown that UV irradiation can arrest growth, suppress chlorophyll biosynthesis and inhibit electron transport and net photosynthesis. Most models agree that a light-induced impairment in electron transport leads to damage and an increased rate of turnover of the DI protien of photosystem 2 reaction centre. Photosystem 1 is somehat resistant to UV-B irradiation. In a study by Ibelings UV-B high photon irradiance was found to be damaging while low photon irradiance in subsurface layers of a bloom may offer protection against heat injury. Weis found that at low photon irradiance the light-induced intra-thylakoid acidification stabilizes thylakoid membranes and retains the normal conformation of photsystem 2.

UVB irradiation does not bring about major structural damage but affects overall photochemical efficiency through dissociation of certain protiens.

Tolerance and the minimal inpacts of UV stress is related to a complex system of protective mechanisms. This probably draws its origins from history. Since incident UV irradiation in the past was probably much higher because of lack of stratospheric ozone.

 

[OsWiZzLe]

I've used what considerd to be the strongest UVB bulbs on the market Aqualine Buschke 10k 2 400 watters ...i've tried flowering the whole 9 weeks with them....then the last 2 weeks...and so on...my results...they dont do shit but burn ur skin and eyes...if u want to benefit from UV growing cannabis..... trying to growing outdoors at the highest point on the Island of Maui...nowhere else on earth is the more UV shining down on earth...hhhhmm no wonder outdoor Island herb is so fucken sick ....

I think its funny how u guys think an MH bulb or CMH emit any UVB.... try buying a UV meter and test it yourself....its funny how if u want to think something is working when its not

 

[OsWiZzLe]

http://www.personal.psu.edu/sbj4/aquarium/articles/MetalHalideLamps1.htm

 

[LastWaltz]

IMHO, this is an example of confounding variables. I have not seen one scientifically sound positive test of UV light on increasing potency. Neither has anyone provided an explanation of how UV light is supposed to do this. People keep providing examples, where any number of variables could be contributing to the potency (this is of course subjective since no one has provided a measured THC content of comparison plants) more likely the high elevation in these cases influence other grow factors, soil and atmosphere composition, temperatures, precipitation etc.