Finishing times, Photoperiod, Latitude, and how it all works!!

[BACKCOUNTRY]

Mr. Growitall- I could see how you could see earlier blooming with clones planting after the solstice, but with seed grown plants it is a different matter.
Seeds started later than mid June often lag behind their earlier sisters, I once tried starting plants in early July and ended up harvesting 3 weeks later than their April started sisters.

Generally, the basic rule is that most photo sensitive strains(that being any strain that uses light cycles to trigger bloom) of Cannabis gain the ability to bloom(mature) at about 7-9 weeks of age.
Now take a strain that is triggered to bloom @ July 25th, if you started the seeds around June 25th(the solstice is June 21st) that would give the plants 4 weeks to start blooming. Chances are the plants wouldn't be triggered for at least 3 weeks more, when they are more mature, even if they did bloom on time they would be tiny!

But like I said, I can see how this might work with clones Vs. seed grown plants, considering that they are mature already at planting, just waiting to bloom!

I disagree with the idea that the moon has anything to do with starting bloom, photosenstive plants(not just Cannabis) can not register moonlight because it is too weak to trigger their photchromatic cells. It does not seem to play any role what so ever.

 

[Dignan]

The idea behind plants from seed can start blooming earlier when put out later (that sounds confusing, but hopefully you guys know what I mean...) is that the older plants build up more floral inhibitors, hormones that "hold" a plant in a vegetative state and "resist" flowering. Younger plants have less time to build up floral inhibitors and will begin flowering earlier. Per Robert Connell Clarke, at least. Clarke allowed that this was just his own hypothesis, not necessarily fact.

My own experience this year has supported that theory... but what I've been doing hardly classifies as a scientific experiment and includes far too many variables to draw conclusions from.

And just because a plant begins flowering earlier doesn't mean that it necessarily finishes sooner.

 

[Guest]

Yes of course planting seeds after solstice is different, for this the plant must be old.
Though, growing plants from seeds indoors for a couple months on 24h light to then plant outside once solstice is passed would , I beleive, finish earlyer than if vegged outside. (example planting mothers)

As for the moon having any effect I can't say I have experimented with that but it makes sense to me. In a grow room it is always important to block any light leaks so that the dark period is completely dark. Many use green lights to do maintenance durring the dark cycle. The moon gives off white light, enough to be able to see the plants fairly well. No one would want that in their flowering room. In the situation where the outdoors is treated as a flowering room I would think that moonlight is not negligable. I would love to hear from someone who has experimented with that. Backcountry, do you have any info to back your disagreement or are you just supposing like me?

 

[Guest]

Dignan, I've been told by a breeder that the earlier a plant is put outside before solstice, the longer it takes to finish flowering. Because the plant figures out at what latitude it's at by how long it takes before the longest day of the year (solstice). For example, a self-seeded plant in the far north would be a lot smaller than one half way to the equator come solstice, because there was less time to grow from the last days of frost. So logicaly, the plant will have less time to finish before the first frost. So according to him plants adjust their schedule this way.

But I think it is not really based on time spent before solstice because indoors it doesn't matter how long you veg, the flowering time is consistent. Rather it is based on the rate of increase of light. Example: At the summer solstice (21 June 2003), the next day is just 4 seconds shorter. At the autumnal equinox (23 September 2003), the next day is 2:08 minutes shorter. This is the same for increasing light, the nearer to solstice the lesser the rate of change. So a plant could know at a very young stage how long it has to veg by the rate of change in daylight. Thus it could calculate the aproximate time it has to flower.

Keeping a plant on 24/0 or 18/6 light until being put outside or in a flowering room would then be a way to blind the plant into thinking it has all the time in the world. But then when the light cycle is changed, the plant switches immediately in panic to flowering thus giving consistant flowering times for each strain.

Anyone have any clue as to what I'm talking about? Do I think too much? Maybe I've been out of grass for too long...

 

[Guest]

Here is a graph to illustrate my point:

 

[BACKCOUNTRY]

Well, the basic consensus on OG and so far here(as far as I can see) is that Moonlight is simply too weak to have affect, despite how bright it might seem with a full moon on a super clear night, out away from human made light.

Full moon light is 500,000 times fainter than sunlight for one, very dim!

Here is a webpage that speaks about photoperiodism and controling it in commercial greenhouses, its on the University of Massachusetts website- PHOTOPERIOD CONTROL SYSTEMS FOR GREENHOUSE CROPS, U-Mass

Here is a quote from that page-

....Another important question is, can moonlight affect photoperiodic responses? The answer is no. The maximum intensity of bright moonlight is 0.02 ft-c, and this is not enough to be perceived as daylight by photoperiodically responsive plants....

 

[BACKCOUNTRY]

Dignan, I've been told by a breeder that the earlier a plant is put outside before solstice, the longer it takes to finish flowering. Because the plant figures out at what latitude it's at by how long it takes before the longest day of the year (solstice). For example, a self-seeded plant in the far north would be a lot smaller than one half way to the equator come solstice, because there was less time to grow from the last days of frost. So logicaly, the plant will have less time to finish before the first frost. So according to him plants adjust their schedule this way...

-This almost seems like a plausable theory, but I have to say again that this is not my experience with seed grown plants grown under natural light. Perhaps this does work with some very early Indica varieties(such as those commonly grown outdoors in N. Europe and Canada), but I have never seen this in my October finish Indica dominated strains.

 

[BACKCOUNTRY]

Perhaps you should post this question in a new thread so you can get more input from more members?

 

[Dignan]

I've heard many times about the smallest light leaks causing plants to reveg or, more commonly, turn hermaphrodite. I've even heard people claim that the little red power light on a heater or the cherry on a cigarette can have the same effect.

I personally have never experienced such small amounts of light triggering a plants behavior, but if that does occur, I would say that the Full Moon is certainly far brighter than those sources of light... which would lead me to suspect that it's the spectrum of light emitted by the Full Moon that accounts for the fact that its light doesn't affect photosensitive plants, rather than the relative intensity of the Moon's light.

Just thinking outloud here.

 

[Grasso]

Hello,

Generally, the basic rule is that most photo sensitive strains(that being any strain that uses light cycles to trigger bloom) of Cannabis gain the ability to bloom(mature) at about 7-9 weeks of age.

Not a bit sooner, like one month, if the seedling is raised under good conditions and 12-hours-long days?

Photoperiod is sensed by the phytochrome system which has its peak absorbation at 670 nm, say far-red. Green light has thirty times or so less effect than far-red light has. A red "power on" light in a box can surely confuse plants.

The path of the sun is probably also a factor. Furthermore months of rain delay flowering. The effects of moonlight may be entwined with other mysterious effects. Somehow noone who grows marijuana keeps her candle lit long enough to gain experience over the years and finally draw her conclusions and reveal these secrets to us.

Shiva Mack is a drug/fiber hybrid and flowers right now. Some Shiva Haze (Sensi x Nirvana) are starting to flower. The drug/fiber cross Ruderalis Indica does not flower yet; a hinted auto-flowering intermezzo ended in summer.

Uli

 

[BACKCOUNTRY]

PHOTOPERIOD CONTROL SYSTEMS FOR GREENHOUSE CROPS, U-Mass

....Another important question is, can moonlight affect photoperiodic responses? The answer is no. The maximum intensity of bright moonlight is 0.02 ft-c, and this is not enough to be perceived as daylight by photoperiodically responsive plants....

^^This webpage and quote from the University of Massachusetts pretty much sealed the deal for me, a Professor who studies and teaches this for a living pretty much totally convinced me, you guys really should go check this out, I mean this guy is pretty serious, the reason the moon has no affect is that it is just too dim to begin with.

Take into account how dim the full Moon is, depending on the condition of the atmosphere full sunshine is between 32000 and 100,000 lux, at sunrise/sunset the light is about 400 lux, the full moon on the most clear night is about 0.25 lux max.

I think it is always a good thing to seal all the light you can out of a grow room, but I think plants will actually tolerate quite a bit more than they are often given credit for, lord knows my indoor grows through the years have delt with their share of minor light leaks, but I have only seen hermis online, never in person.

 

[Dignan]

Well said, BC. I'm inclined to agree, actually.

I do think the absolute intensity of the Sun vs. artificial lights indoors might play into it all. The relative brightness of a tiny light leak compared to the brightness of a 1000w HPS lamp is probably more significant than the brightness of the Moon compared to the Sun. Know what I mean?

Either way... outdoors, I don't think the Moon has any affect and it is likely due to its dimness and perhaps spectrum also plays some part in it.

And outdoors RULES, so those are the rules we play by here.

 

[BACKCOUNTRY]

Agreed on all points


Thankyou to whoever stickied this thread, I'm honored that you think this thread may be helpfull to the community at large.
These subjects are some of the most mis-understood by growers, especially for those new to the outdoors.
I am myself still trying to comprehend so many of the different factors involved in photoperiodism, and invite others to add their tidbits, so that we may all be a little more enlightened.

 

[Guest]

I like to read what the tropcal guys are doing. They are fun and different than North America. Chaman and Paz Verde Radical both show that when they planted indica-dom plants that they imediately go into flower. They show photos of one inch plants that are all bud. It is sort of funny looking, but educational as well.

I have read in one online grow guide that one can get an early harvest by going from 24/7 lighting indoor to outdoor spring lighting to get an early harvest, and then after that letting them reveg and get a second crop in the fall. Has anyone ever been successful at this?

One thing I would love to read is if there is anything in photo-period or other factors to increase thc or resin. I know that that is said to be genetic, but I still feel deep inside that something can be done to increase thc.

 

[BACKCOUNTRY]

I like to read what the tropcal guys are doing. They are fun and different than North America. Chaman and Paz Verde Radical both show that when they planted indica-dom plants that they imediately go into flower. They show photos of one inch plants that are all bud. It is sort of funny looking, but educational as well.

Yep, this is because their day length doesn't really change much from season to season, especially so as you get closer to the equator, almost always too short to veg non-tropical strains.
I've heard many stories from growers in Hawaii, and SE Asia concerning this, reading and trying to answer these questions were part of the inspiration to study photoperiod.
Were the plants they(Chaman and Paz Verde Radical ) used for these demonstrations vegged inside under long light cycles first, or were they started under totally natural sunshine?


I think the only way we as the growers can really increase the THC is by making sure that the sunshine recieved by our plants is always as strong as we can get throughout the bloom cycle, and even then I do believe it is mostly up to the genetics after all.

 

[Lambsbreath]

i'm 5° north to equator ( south amerika ) and i can testify that all pure indicas will start flowering after two weeks of veg outdoor, males sometime showing only after 10 days.
I had tested outdoor few nirvana strains like White widow - ak48- PPP- NLx Haze ( it looked like pure NL very broad leaves),papaya, and had only bonzaï type plants, too indica for the 12/hour day light regime.

The only one of their white strain who didn't autoflower too soon was the blue mystic , some pheno would veg for 15 days while other for 3 weeks or a month , and finishing with a plant from 30 cm to 1meter max , with one main cola "one bud" style.

I think it may be because blue mystic have some oaxacan genetic inside that it doesn't autoflower as soon. as others strains mentioned above.

The more sativa you add in it the longer it will veg; 50/50 sativa -indica hybrid like California Orange bud will veg minimum 2 months, Jack Horor minimum 2month and half , Haze 3 to 4 months, Pure local sativa landrace vegging sometime more than 6 months.

I'm now mostly playing with dominant sativas strains but still like to have some shorter strain in the garden like Blue Mystic which can be done from seed to harvest in 2 to 3 months depending on the weather , pheno, and size of the pot.

As i can plant weed anytime of the year, i try to have a perpetual harvest of 10 to 20 females every month. Indicas dominant hybrid can grow best during dry season from Augustus to December here.


One Love from the Amazonian Jungle

 

[BACKCOUNTRY]

Thanks for that personal testimony lambsbreath! Very nice!

All this talk of plants going straight to flower in the perpetual(or near perpetual) outdoor bloom room of the tropics adds more potentcy to my belief that all photosensitive(meaning non-autoflowering) Cannabis plants have a geneticly predetermined preference for the natural photoperiod they like to bloom under, rather than simply blooming when they sense the days are getting shorter.
Most Indicas and Indica dominated hybrids will bloom in less than 15 hours of light, and will bloom faster and faster as the day shortens more and more. Some strains seem to be able to bloom even under 16 hours or more, even without being autoflowering.

I have heard in the past that some Tropical Sativas are thought to be autoflowering more than photoperiod sensitive or possibly a mix of the two, perhaps timing their life cycles with the rainy and dry seasons rather than purely according to the cycles of the sun(the day never gets much longer than 12-13 hours on the equator, not much change in the sun cycles).

 

[Dignan]

I was told by Reeferman a few months ago that at the equator all plants will flower right away... sativas that are native to that kind of photoperiod/region flower right away but due to The Sativa Stretch, they'll always get much bigger than any indica would... but that they never get full-size like the monster sativas we get far from the equator.

Is that not correct?

 

[BACKCOUNTRY]

I assume it is, I was looking for this type of info from people that know, so maybe I have heard wrong concerning the autoflowering tropicals.

 

[Dignan]

No worries... we'll get to the bottom of this!! Inspector BC always gets his man!

Another great BC thread...