Total darkness period before flowering
- Thread starter vangs
- Start date
Its pretty much triggering the plants by letting them know its time flower meaning the veg season is over and its close to being fall season/flowering season. I read that 2-3 days total darkness. I think the reason is they flower sooner then later and it helps flowering in some type of way. I mean this step is really up to you.
oldhippie64
New Member
the amount of darkness depends on who you ask. I've heard 24-72 hrs of darkness when you flip lights to 12/12 . it is to speed up the onset of flowering. the reason this is that the plant makes a hormone during the night that during the day gets destroyed(it's a light sensitive molecule). the hormone triggers flowering. So when you give them this darkness it gets to make enough hormone to all at once to start flowering instead of having to wait for the build up from just going 12/12 without the darkness.
Fuzzy Duck
Well-Known Member
I'm not sure why people do x period of darkness before flowering, to me it does not make any real sense at all !
In nature when growing out doors you don't get 3 days of total darkenss to stimulate flowering as its all based on photogenic period of day light normally assoicated with 12/12 to trigger plant hormones for flowering...
Fuzzy Duck
Well-Known Member
By how much does this speed up flowering by ?
oldhippie64
New Member
it speeds up the start of flowering, it doesn't speed up flowering time. they still take as long to finish from the start. The start of flower isn't when you flip lights, it's when the plant has enough hormone built up to flower. it takes about a week if you just flip light for hormone levels to get high enough to start flowering. with a period of darkness it's almost as soon as light come back on. so I'd say a couple days to a week sooner
Fuzzy Duck
Well-Known Member
Well it only takes 5 to 10 days for a plant to start flowering tho.
Clones will have pre flowers on as they are already sexed & come from a mature plant which may take as little as a few days to start flowering.
Plants from seeds... well they not going to start flowering intill plant is mature enough to do so & at best takes about a week.
I never give a dark period before flowering, like fuzzy duck said, why??? nature doesn't do this so why do it to the plants?? If someone could show me some actual scientific proof of a dark periods effectiveness I may switch my ways, but otherwise I'm sticking with what nature does.. btw I usually see flowers develop in 4-6 days.
oldhippie64
New Member
I don't understand the it's not natural comments as indoor grows don't follow nature. Our lighting schedules don't follow any natural patterns and our spectrum doesn't change thru out the day as in nature, they are a constant. Then there's hydroponics which isn't natural at all but is good way to grow. What I'm trying to say is indoor grows aren't about replicating nature, it's about giving them the best conditions we can. I see tk gets his to flower a little faster then others report by reducing lights more then normal but this could be strain related.
Fuzzy Duck
Well-Known Member
I took a brief look at plant hormones which may factor into flowering by inducing total darkness to increase hormone & earlyer development.
Well a lot of us would be aware of auxin hormone a pretty interesting hormone which doesn't like light & is present in the apical dominate shoots... plays a good role in growth/plant organ development & slightly less in flowering.
Anyway heres a copy 'n' pasted extract.
Organization of the plant
As auxins contribute to organ shaping,[4][5] they are also fundamentally required for proper development of the plant itself.[4] Without hormonal regulation and organization, plants would be merely proliferating heaps of similar cells. Auxin employment begins in the embryo of the plant, where directional distribution of auxin ushers in subsequent growth and development of primary growth poles, then forms buds of future organs. Next, it helps to coordinate proper development of the arising organs, such as roots, cotyledons and leaves and mediates long distance signals between them, contributing so to the overal architecture of the plant.[4] Throughout the plant's life, auxin helps the plant maintain the polarity of growth,[4] and actually "recognize" where it has its branches (or any organ) connected.
An important principle of plant organization based upon auxin distribution is apical dominance, which means the auxin produced by the apical bud (or growing tip) diffuses (and is transported) downwards and inhibits the development of ulterior lateral bud growth, which would otherwise compete with the apical tip for light and nutrients. Removing the apical tip and its suppressively acting auxin allows the lower dormant lateral buds to develop, and the buds between the leaf stalk and stem produce new shoots which compete to become the lead growth. The process is actually quite complex, because auxin transported downwards from the lead shoot tip has to interact with several other plant hormones (such as strigolactones or cytokinins) in the process on various positions along the growth axis in plant body to achieve this phenomenon. This plant behavior is used in pruning by horticulturists.
Finally, the sum of auxin arriving from stems to roots influences the degree of root growth. If shoot tips are removed, the plant does not react just by outgrowth of lateral buds – which are supposed to replace to original lead. It also follows that smaller amount of auxin arriving to the roots results in slower growth of roots and the nutrients are subsequently in higher degree invested in the upper part of the plant, which hence starts grow faster.
Effects
A healthy Arabidopsis thaliana plant (left) next to an auxin signal-transduction mutant
Crown galls are caused by Agrobacterium tumefaciens bacteria; they produce and excrete auxin and cytokinin, which interfere with normal cell division and cause tumors.
Auxin participates in phototropism, geotropism, hydrotropism and other developmental changes. The uneven distribution of auxin, due to environmental cues, such as unidirectional light or gravity force, results in uneven plant tissue growth, and generally, auxin governs the form and shape of plant body, direction and strength of growth of all organs, and their mutual interaction.[5]
Auxin stimulates cell elongation by stimulating wall-loosening factors, such as elastins, to loosen cell walls. The effect is stronger if gibberellins are also present. Auxin also stimulates cell division if cytokinins are present. When auxin and cytokinin are applied to callus, rooting can be generated if the auxin concentration is higher than cytokinin concentration. Xylem tissues can be generated when the auxin concentration is equal to the cytokinins.
Auxin also induces sugar and mineral accumulation at the site of application.
Wound response
Auxin induces the formation and organization of phloem and xylem. When the plant is wounded, the auxin may induce the cell differentiation and regeneration of the vascular tissues.
Root growth and development
Auxins promote root initiation.[15] Auxin induces both growth of pre-existing roots and adventitious root formation, i.e., branching of the roots. As more native auxin is transported down the stem to the roots, the overall development of the roots is stimulated. If the source of auxin is removed, for example the tips of stems are trimmed, the roots are less stimulated accordingly, and growth of stem is supported instead.
In horticulture, auxins, especially NAA and IBA, are commonly applied to stimulate root initiation when rooting cuttings of plants. However, high concentrations of auxin inhibit root elongation and instead enhance adventitious root formation. Removal of the root tip can lead to inhibition of secondary root formation.
Apical dominance
Auxin induces shoot apical dominance; the axillary buds are inhibited by auxin, as a high concentration of auxin directly stimulates ethylene synthesis in lateral buds, causing inhibition of their growth and potentiation of apical dominance. When the apex of the plant is removed, the inhibitory effect is removed and the growth of lateral buds is enhanced. Auxin is sent to the part of the plant facing light, and this promotes growth towards that direction.[16]
Fruit growth and development
Auxin is required for fruit growth and development and delays fruit senescence. When seeds are removed from strawberries, fruit growth is stopped; exogenous auxin stimulates the growth in fruits with seeds removed. For fruit with unfertilized seeds, exogenous auxin results in parthenocarpy ("virgin-fruit" growth).
Fruits form abnormal morphologies when auxin transport is disturbed.[17] In Arabidopsis fruits, auxin controls the release of seeds from the fruit (pod). The valve margins are a specialised tissue in pods that regulates when pod will open (dehiscence). Auxin must be removed from the valve margin cells to allow the valve margins to form. This process requires modification of the auxin transporters (PIN proteins).[14]
Flowering
Auxin plays also a minor role in the initiation of flowering and development of reproductive organs. In low concentrations, it can delay the senescence of flowers.
Ethylene biosynthesis
In low concentrations, auxin can inhibit ethylene formation and transport of precursor in plants; however, high concentrations can induce the synthesis of ethylene. Therefore, the high concentration can induce femaleness of flowers in some species.[citation needed]
Auxin inhibits abscission prior to formation of abscission layer, and thus inhibits senescence of leaves.
Gonna do some home work on this matter of darkness before flowering as some seem to swear by it ! but not totally convinced by it myself.
Must be some other plant hormones to take a look at
Well a lot of us would be aware of auxin hormone a pretty interesting hormone which doesn't like light & is present in the apical dominate shoots... plays a good role in growth/plant organ development & slightly less in flowering.
Anyway heres a copy 'n' pasted extract.
Organization of the plant
As auxins contribute to organ shaping,[4][5] they are also fundamentally required for proper development of the plant itself.[4] Without hormonal regulation and organization, plants would be merely proliferating heaps of similar cells. Auxin employment begins in the embryo of the plant, where directional distribution of auxin ushers in subsequent growth and development of primary growth poles, then forms buds of future organs. Next, it helps to coordinate proper development of the arising organs, such as roots, cotyledons and leaves and mediates long distance signals between them, contributing so to the overal architecture of the plant.[4] Throughout the plant's life, auxin helps the plant maintain the polarity of growth,[4] and actually "recognize" where it has its branches (or any organ) connected.
An important principle of plant organization based upon auxin distribution is apical dominance, which means the auxin produced by the apical bud (or growing tip) diffuses (and is transported) downwards and inhibits the development of ulterior lateral bud growth, which would otherwise compete with the apical tip for light and nutrients. Removing the apical tip and its suppressively acting auxin allows the lower dormant lateral buds to develop, and the buds between the leaf stalk and stem produce new shoots which compete to become the lead growth. The process is actually quite complex, because auxin transported downwards from the lead shoot tip has to interact with several other plant hormones (such as strigolactones or cytokinins) in the process on various positions along the growth axis in plant body to achieve this phenomenon. This plant behavior is used in pruning by horticulturists.
Finally, the sum of auxin arriving from stems to roots influences the degree of root growth. If shoot tips are removed, the plant does not react just by outgrowth of lateral buds – which are supposed to replace to original lead. It also follows that smaller amount of auxin arriving to the roots results in slower growth of roots and the nutrients are subsequently in higher degree invested in the upper part of the plant, which hence starts grow faster.
Effects
A healthy Arabidopsis thaliana plant (left) next to an auxin signal-transduction mutant
Crown galls are caused by Agrobacterium tumefaciens bacteria; they produce and excrete auxin and cytokinin, which interfere with normal cell division and cause tumors.
Auxin participates in phototropism, geotropism, hydrotropism and other developmental changes. The uneven distribution of auxin, due to environmental cues, such as unidirectional light or gravity force, results in uneven plant tissue growth, and generally, auxin governs the form and shape of plant body, direction and strength of growth of all organs, and their mutual interaction.[5]
Auxin stimulates cell elongation by stimulating wall-loosening factors, such as elastins, to loosen cell walls. The effect is stronger if gibberellins are also present. Auxin also stimulates cell division if cytokinins are present. When auxin and cytokinin are applied to callus, rooting can be generated if the auxin concentration is higher than cytokinin concentration. Xylem tissues can be generated when the auxin concentration is equal to the cytokinins.
Auxin also induces sugar and mineral accumulation at the site of application.
Wound response
Auxin induces the formation and organization of phloem and xylem. When the plant is wounded, the auxin may induce the cell differentiation and regeneration of the vascular tissues.
Root growth and development
Auxins promote root initiation.[15] Auxin induces both growth of pre-existing roots and adventitious root formation, i.e., branching of the roots. As more native auxin is transported down the stem to the roots, the overall development of the roots is stimulated. If the source of auxin is removed, for example the tips of stems are trimmed, the roots are less stimulated accordingly, and growth of stem is supported instead.
In horticulture, auxins, especially NAA and IBA, are commonly applied to stimulate root initiation when rooting cuttings of plants. However, high concentrations of auxin inhibit root elongation and instead enhance adventitious root formation. Removal of the root tip can lead to inhibition of secondary root formation.
Apical dominance
Auxin induces shoot apical dominance; the axillary buds are inhibited by auxin, as a high concentration of auxin directly stimulates ethylene synthesis in lateral buds, causing inhibition of their growth and potentiation of apical dominance. When the apex of the plant is removed, the inhibitory effect is removed and the growth of lateral buds is enhanced. Auxin is sent to the part of the plant facing light, and this promotes growth towards that direction.[16]
Fruit growth and development
Auxin is required for fruit growth and development and delays fruit senescence. When seeds are removed from strawberries, fruit growth is stopped; exogenous auxin stimulates the growth in fruits with seeds removed. For fruit with unfertilized seeds, exogenous auxin results in parthenocarpy ("virgin-fruit" growth).
Fruits form abnormal morphologies when auxin transport is disturbed.[17] In Arabidopsis fruits, auxin controls the release of seeds from the fruit (pod). The valve margins are a specialised tissue in pods that regulates when pod will open (dehiscence). Auxin must be removed from the valve margin cells to allow the valve margins to form. This process requires modification of the auxin transporters (PIN proteins).[14]
Flowering
Auxin plays also a minor role in the initiation of flowering and development of reproductive organs. In low concentrations, it can delay the senescence of flowers.
Ethylene biosynthesis
In low concentrations, auxin can inhibit ethylene formation and transport of precursor in plants; however, high concentrations can induce the synthesis of ethylene. Therefore, the high concentration can induce femaleness of flowers in some species.[citation needed]
Auxin inhibits abscission prior to formation of abscission layer, and thus inhibits senescence of leaves.
Gonna do some home work on this matter of darkness before flowering as some seem to swear by it ! but not totally convinced by it myself.
Must be some other plant hormones to take a look at
Fuzzy Duck
Well-Known Member
Auxin is a plant hormone, which is a growth substance. Auxin is made in cells near the tips of plant roots, or shoots; where the plant divides as it grows. All the time, new cells are being produced, which eventually find themselves behind other cells. These older cells have to grow, by getting longer. Auxin makes these cells get longer - it diffuses backwards towards the older cells. Auxin stimulates these cells to lengthen. Eventually, auxin is broken up by enzymes in the plant. If light is shone on one direction, the auxin tends to accumulate on the other side, the more shady side. The cells on this side therefore grow longer faster, meaning the shoot bends towards the light. This is positive phototropism. The growth of a plant is also affected by gravity. When a shoot is growing laterally, auxin accumulates on the lower surface of the shoot, causing the cells on the lower side of the shoot to grow faster, so the shoot grows up. Besides the shoot, the root is also affected by auxin. The roots are more sensitive to auxin, and when the auxin accumulates (builds up) on the lower side of the root, the high concentration of auxin inhibits (stops/slows down) the growth of the root on the lower surface, therefore the root will grow downwards. This is geotropism.
oldhippie64
New Member
fuzzy that told me more about that hormone auxin then I already knew, it sure does a lot. I think the only way to be sure is to experiment with a set of vegging plants/clones. I say that cause we don't even know everything about how our bodies work, let alone another types of lifeforms. we may not have found the other hormones at play yet.
Fuzzy Duck
Well-Known Member
Thats cool we are all learning, a lot of use just grow plants for smoke/meds most of us don't even understand the basic's involved let alone look into the botany of the subject at hand.
Quite an in depth subject really & even i don't fully understand all of it
I wouldn't call it a science ! more of improving base knowledge for a greater foundation.
Fuzzy Duck
Well-Known Member
The only other hormones in plants worth a note where - strigolactones & cytokinins worth doing some home work but these didn't really play a role in early flowering...
Auxins are pretty much what we're looking at & may appear to be light sensitive as they move to the shaded areas of the plant of the apical dominate stems, also related to plant organ production which we may think off pre flowers/buds/pistals etc
From my own experience a large majority of growth does occur through out the night time period !
This i presume to be the optimal time of auxins hormone & growth ? as light may cause lower levels of the hormone ?
Hence some may believe a prolonged period of darkness may enhance early flowering by increasing hormone level etc !
Now fuzzys theory on this is down to - veg lighting regime...
If using 24/7, 20/4 & even 18/6 may lower auxin levels hence a longer early flowering phase or intill sexed or pistils are formed, due to lack of night/dark hours.
I may put this total darkness before flowering, down to growers using above lighting regime - hence this method being used ?
Where as growers who use a more normal lighting regime or longer dark periods are less likely to suffer with longer/late early flowering as auxin levels may be more normal than when switched to 12/12 flowering regime.
NOTE
Its just fuzzys theory based on logic & what i can learn quickly about the matter !
It may be wrong !
I'm just a guy who's been a gardener for some 20 years expanding his knowledge basis, easy done when knowing the basic's...
P.s - i'm not botanist or hold a degree in the matter & all of the above is a self educated assumption based on what was aviable to me to read asap to form my conculsion !
If interested in the matter, home work/research is always worth while
Auxins are pretty much what we're looking at & may appear to be light sensitive as they move to the shaded areas of the plant of the apical dominate stems, also related to plant organ production which we may think off pre flowers/buds/pistals etc
From my own experience a large majority of growth does occur through out the night time period !
This i presume to be the optimal time of auxins hormone & growth ? as light may cause lower levels of the hormone ?
Hence some may believe a prolonged period of darkness may enhance early flowering by increasing hormone level etc !
Now fuzzys theory on this is down to - veg lighting regime...
If using 24/7, 20/4 & even 18/6 may lower auxin levels hence a longer early flowering phase or intill sexed or pistils are formed, due to lack of night/dark hours.
I may put this total darkness before flowering, down to growers using above lighting regime - hence this method being used ?
Where as growers who use a more normal lighting regime or longer dark periods are less likely to suffer with longer/late early flowering as auxin levels may be more normal than when switched to 12/12 flowering regime.
NOTE
Its just fuzzys theory based on logic & what i can learn quickly about the matter !
It may be wrong !
I'm just a guy who's been a gardener for some 20 years expanding his knowledge basis, easy done when knowing the basic's...
P.s - i'm not botanist or hold a degree in the matter & all of the above is a self educated assumption based on what was aviable to me to read asap to form my conculsion !
If interested in the matter, home work/research is always worth while
LMFAO At ur first sentence I know right!! and No its all strains that Ive tried that with.
oldhippie64
New Member
thanks tk it's good to know it wasn't strain related. not that I thought it was. it's easy to think you are replicating the natural conditions after all it's a natural product. but really nature isn't that simple. I wasn't trying to be funny just honest. Hope I didn't offend anyone.
Muttt
New Member
I'm offended ..... LOL.
I give a break of 36 hours complete darkness between veg an flolwer and in my experience it does speed up onset of flowering. How can i say that? Well firstly i have hundreds of indoor grows behind me and second because i have done like for like experiments. i found on average flowering begins 3-4 days sooner than not giving the dark period. Not only that but with the dark period i find the plant develops more flowering sites. These experiments involved giving plants identical nutrient schedule and clones from same mother. I did this for 6 grows and got similar results each time. In the grand scale the differences arent huge but they are there. Im not a scientist so i cant give scientific explanation but in my experience from doing it there is a diff. Its like wen people say removing fan leaves have a neg effect on plant and plaant needs them but have never tried high defoliation so they dont even know. Just because something is in a book doesnt make it gospel. Just as diff strains may react differntly to dark period before flower. These are the strains i used: White widow, Super Lemon Haze, The Church, A.M.S, Big Bang and Himalayan Gold. There was faster flower start and more flower sites on all these strains. Hope this helps.
- Thread starter
- #20
yeah man, deffinetly helpful.. i just finished a 48hr dark period. know i know that i did the right thing. if you dont mind me asking, i trim offf alot of fan leaves during veg nd flower, manly because i grow lot of indicas and the leaves sometimes cover the whole plant. ive read that its bad for the plants because of stress and shock and it will slow growth and reduce yield but that was comming from people who never actually defoliated. whats your opinion on the subject?
