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72 Hours Of Darkness Before I Harvest?

Discussion in 'Cannabis Harvesting & Curing' started by mikeb437, May 24, 2018.

  1. I’ve seen a couple articles where it says to leave your plant in total darkness for 72 hours before you harvest. Is this a legitimate technique?
     
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  2. Smerb

    Smerb

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  3. Madbud

    Madbud

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    Also cutting and hanging in darkness, it won’t hurt.
     
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  4. G gnome

    G gnome

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    Imo leaving plants in the dark for 3days is a waste of time n space. Drying and curing in the dark however, is a necessity
     
  5. Smerb

    Smerb

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    The studies are out there, its done and not done. Some growers will do this if they have the time/effort, I was led to this by accident, so I studied it and im still going to get more info,thats smerb for ya...Photosynthesis in a Changing World is a book that could be looked into also.

    Copy/paste stuff below.




    Stichting Institute of Medical marijuana (SIMM), the first company to sell marijuana through the pharmacies of Holland, has been investigating the medical possibilities of cannabis, together with TNO laboratories and the University of Leiden.


    One of their discoveries has been that to keep the ripe plants in the dark before harvesting could increase their potency.SIMM’s growers separated a crop of mature plants, harvested half of them and kept the other half in absolute darkness for 72 hours before cutting and drying. Analysis of the resulting dried buds showed that some varieties had seen an increase of THC of up to 30%, while CBD and CBN remained the same."

    Thc degrades in light. Thc is used by the plant as a sunscreen, primarily to deflect UV-b which damages the molecule. The thrichomes are refracting sunlight away from the plant protecting it from the damaging uv-b. The plant produces these trichomes in the twilight hours before sunrise in order to protect itself from the sun. Extending this twilight dark period allows for the plant to continue producing thc without it being damaged by light.
     
  6. heisen

    heisen

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    I'm not so sure a plant produces trichomes for sun screen.if this was true there would be a very noticeable difference in trichs that are directly under the lights.seems to me it's a genetic thing,seems like the lower buds are usually always the frostiest.i know lower temps will make plants appear frostier for sure.there is no scientific evidence I'm aware of that proves why they produce trichs.lots of theory but I think it's for bug protection.makes them not tasty to animals.thc could be like a natural repellant against certain bugs.i know when you stress the plant out they will frost up.
    Not buying the whole Uv bit
     
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  7. GT21

    GT21 I like soup Supporter

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    30% more huh? Wow.
     
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  8. GT21

    GT21 I like soup Supporter

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    Another wow hahaha
    https://www.sciencedirect.com/science/article/pii/S0098847297000051
     
    Last edited: May 27, 2018
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  9. Smerb

    Smerb

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    All indoor growers should be trying to replicate the suns powerful spectrum. That's all I have to say about that.....
     
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  10. heisen

    heisen

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    If that was case outdoor plants would be in higher demand than indoor,I cant give outdoor shit away.
    Trichs come down to genetics and temperature,only thing i ever seen to make a difference.still not buying the whole uv thing.cmh is supposed to have more uv than hps but I see no difference in trichs on the same clones on both different runs.
    Also why do lower buds away from the lights always seem more frosty than the ones right up under the lights?
     
  11. Smerb

    Smerb

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    Some of these studies are NOT on cannabis, that is a bit confusing. The pink carnation:
    Abstract
    Plants respond to environmental stimuli in a diversity of ways including the production of secondary metabolites. Biosynthesis of plant phenolics, including flavonoids, is frequently activated in response to a variety of abiotic and biotic stressors (e.g. extreme temperatures, high radiation, pathogens, etc.). This induced reaction is typically assumed to be a plastic response, but the components attributable to plasticity vs genetic variance in these components are poorly understood. Here, we investigate the variation in flavonoid production (anthocyanins and flavones) in petals and in photosynthetic tissues (calyces, leaves and stems) of Silene littorea. We performed a common garden experiment with maternal families from three populations in which plants were exposed to different light treatments (sun exposure and shade). The concentrations of anthocyanins in photosynthetic tissues increased when plants were exposed to sun, except for leaves that showed very low quantities of anthocyanins in both light treatments; yet flavones are produced constitutively in both sun and shade treatments. The synthesis of both anthocyanins and flavones is mostly plastic, with 25 to 43% of total phenotypic variance explained by light environment. We found significant environmental effects in anthocyanin biosynthesis in calyces and stems, and in flavone production in all photosynthetic tissues. Petals showed considerably less plasticity in anthocyanin production in contrast with the accumulation of these compounds in calyces and stems. Flavones exhibited less than half of the degree of phenotypic plasticity compared to anthocyanins in calyces and stems. Overall, these results provide new insights into the degree of tissue-specific plasticity and flavonoid-specific response. Variable plasticity between flavonoids types in petals and photosynthetic tissues may allow this annual plant to differentially respond to changing light environments, while maintaining constitutive petal color in response to pollinators.
    This copy/paste has nothing to do with cannabis. It just shows how much information is out there but hard to decipher.
     
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  12. Smerb

    Smerb

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    Trichome density and its UV-B protective potential are affected by shading and leaf position on the canopy. Copy/paste
     
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  13. Smerb

    Smerb

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    each bud site gets the same flood of nutes/water. the shaded sites are protected
     
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  14. Smerb

    Smerb

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    I love some greenhouse bud. Full spectrum sun grown, clean environment. We didn't have these lights 20 years ago. I started with the sun but now im indoor, kinda sucks. kinda
     
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  15. G gnome

    G gnome

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    They definitely had lights in 1998

    https://www.bulbs.com/learning/history.aspx?mobile=true
     
  16. heisen

    heisen

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    First grow I ever seen was some crippy in Daytona beach in a small room with some t12 floros back in 95.some other dudes would use stolen mercury vapor street lamps.
     
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  17. G gnome

    G gnome

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    Theyve been usin mh n hps since at least the 80's
     
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  18. Smerb

    Smerb

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    Im talking todays bulbs. The uv T5's. SolisTek. Cmon guys. CMH. Electronic ballasts. Led. etc.
     
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  19. PharmHand

    PharmHand

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    It’s not that hard to decipher, you just have to have an open mind and be WILLING to learn. The info is out there, on this site even- years ago.... This is nothing new, but you know that. Some just don’t believe in/trust/ understand science and how peer reviewed studies by people FAR smarter than they are can save them the time and trouble of their own trial and error. Post links, they won’t read them. Everybody learns differently I suppose. You can lead a horse to water.......
     
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  20. PharmHand

    PharmHand

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    I was using Hortilux super HPS in 2000. My uncle used eye ultra ace mh bulbs in 96 which btw put out more uv than the paltry amount cmh do. I had 430watt Philips son agro enhanced spectrum HPS back in 95 which put out just as much uv as Philips 3k cmh. Honestly I feel uv is a little over hyped. Some is important but too much can ugly up a plant fast. The 10k finishing mh put out a good amount of uv and will force your plants to finish faster and purp quickly but the numbers are really close
     
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