Cannabis, the effect from increasing photo-period by only 15 or 30 min.

[SpaceJunkOG]

1st pic is a Mango (KC Brains) that I grew in 2011, back then I was experimenting with increased light timing from 12:30/13:30 to 13/11. Note that the leaves ALL have an Indica look to em

2nd pic is my current Mango now in week 5 of flower. Light timing is 10:30/13:30. You can see that the lower leaves are all fat and Indica looking as they were made in Veg under 18/6 (was before I started playing with Gaslight veg) (which I love by the way) and all the new leaves are skinny Sat looking leaves

crazy. I do 10:30/13:30 right now too and I also have a Durban that goes amber in like week 5 or 6 (and finishes in 10), i think you were the one who mentioned the same thing about Durban earlier in the thread? It does it to other African landraces as well, . . . . the trichs start going amber halfway through, while the rest are clear, the cloudiness doesn't even set in until around 13 - 14 wks, then they finish around 16wks with mostly cloudy and a bunch of amber. the high still completely cerebral. never seen anything like it with other genetics. not sure how big a role the photoperiod plays.

the whole reason for 10:30 daylength for me was emulating South Africa's daylength because that's a majority of the genetics i grow right now, I want them to feel at home. it's about 10:30 visible light hours during what would be their harvest season. i start at 11/13 and go down to 10:30 in 1 minute increments each day for the first 30 days of flower.

 

[shaggyballs]

Red light is suppoed to be the key to running long light cycles.
Is anyone using red light at night to run longer than 12 hours in flower?

 

[Charles Dankens]

Red light is suppoed to be the key to running long light cycles.
Is anyone using red light at night to run longer than 12 hours in flower?

I built a far red bar and ran 13.5-10.5 for a few runs. It seemed to work fine. When i updated my rig with brighter more efficient cobs i calculated my ppfd to be over 1k . Because the irradiance was so intense i cocluded that 12'hours or even 10.5 hours was likely maxing out cannabis DLI. Likely wasting energy and possibly damaging the plant. Im still running the far red bar but im back on a 12/12 schedule. Getting the plants into lights-out mode more rapidly through 15 mins of far red may shorten flowering period.


Im not an expert at all so my assumptions may be faulty and my reasoning mistaken.







There is tons of info about far red over on riu. Among the canna sites riu seems to contain the most info on led technical details with regards to MJ.

 

[shaggyballs]

This was cutting edge at the time!

Is anyone using red light at night to run longer than 12 hours in flower?

 

[Acannademia]

There's too many garbage posts diluting quality information in this thread... Can somebody please link me with data using both DLI and PPFD as fixed effects?

I am a trained plant scientist. I work in legal cannabis production and monitor cannabinoid levels through HPLC. Here's some anecdotal evidence that in terms of DLI, the answer is 'it depends':

I recently shifted from indoor production facilities to greenhouse. The PPFD I used in indoor was 1000-1600 PPFD but in the greenhouse environment I only have light intensity of 150-400 PPFD. I've always used 12/12 photoperiod, so DLI is much lower in greenhouse. I don't have experimental data comparing DLIs, but I routinely hit the same or better cannabinoid levels in the greenhouse across a large variety of genotypes as what we would typically see in indoor production. In terms of bud morphology, I believe that yield is lower in the greenhouse but flowers are generally as dense as indoor (except when heat-waves hit).

Colleagues of mine have whispered rumours that they've identified genotypes which have peak cannabinoid production at low DLI, as well as other genotypes that have peak cannabinoid production in high DLI (typical of indoor). It is likely that the optimal DLI level is highly genotype-specific and that it can vary dramatically.

 

[Charles Dankens]

I breed, so my current run is a seed run, it is about done with 3 left to harvest, so yield is measured by seeds LOL but quality in my garden is off the charts because of other things I do. The light schedule has not diminished quality at all. and the plants are doing great that I just flipped 2 weeks ago for a bud run, you are welcome to follow along ,,,,
https://www.icmag.com/ic/showthread.php?t=295624

 

[Cannabologist]

There's too many garbage posts diluting quality information in this thread... Can somebody please link me with data using both DLI and PPFD as fixed effects?

I am a trained plant scientist. I work in legal cannabis production and monitor cannabinoid levels through HPLC. Here's some anecdotal evidence that in terms of DLI, the answer is 'it depends':

I recently shifted from indoor production facilities to greenhouse. The PPFD I used in indoor was 1000-1600 PPFD but in the greenhouse environment I only have light intensity of 150-400 PPFD. I've always used 12/12 photoperiod, so DLI is much lower in greenhouse. I don't have experimental data comparing DLIs, but I routinely hit the same or better cannabinoid levels in the greenhouse across a large variety of genotypes as what we would typically see in indoor production. In terms of bud morphology, I believe that yield is lower in the greenhouse but flowers are generally as dense as indoor (except when heat-waves hit).

Colleagues of mine have whispered rumours that they've identified genotypes which have peak cannabinoid production at low DLI, as well as other genotypes that have peak cannabinoid production in high DLI (typical of indoor). It is likely that the optimal DLI level is highly genotype-specific and that it can vary dramatically.

Well... This site is the antithesis of facts, science, and reason. Most posters, and mods, are anathema to reality. Most of the best growers and most scientifically minded people here, have moved on.... What am I still doing lololol



I suspect that you are having better percents, with lower DLI, due to 2 things, first, the added UV light from the sun, and second, the overall color spectrum being more of a "flat" white light, is more "robust" in all the colors.. In other's, I would call this light "quality"..



You'll never get the best quality light that outpaces the sun, and its overall spectral output. We can only try and replicate indoors what the sun does. Any particular indoor lighting source may be a good approximation, but is still not the real mccoy.


Beyond this, UV is the biggest component I believe with these major differences people find in indoor vs outdoor.... More UV as much as you can push it until detrimes equates to better cannabis with higher cannabinoid and terpene percents.

 

[Veggia farmer]

Hmm. This is interessting. Will try to read more later, lot of not so effecient communication here, but some interessting stuff too.!

 

[romanoweed]

@cannabiologist.

The sunintensity is lower at Noth then on the Equator. The spectrum-balance is however same like at equator with exeption of UV-Portion. So, equatorial Strains will not really get enough Watt at north.

Even the spectrum is pretty similar, Plants wont get enough Watt

It applies for any Strain derivering from further to equator than than your Growspot i guess.

 

[f-e]

Pretty sure the light gets warmer as you move away from the equator. In winter, it gets so warm we use blue lights to make ourselves feel better. Look at white balance vs latitude. It's a charted thing

 

[romanoweed]

@f-e
you were right! cause a steeper Angle of Sun the Light looses some Blue-Parts, and therefore should happen at any Tilt, the deeper , the less blue.

How much i just couldnt find out, tho. I guess its not that much, cause i would see it and say: wow at Northpole its always redish, but i had to read it to believe..

 

[Veggia farmer]

So then strains at an higher latitude is naturally adapted to less blue.

So for more indica expression more red and sativa with more blue?

The sativa smokers got the blues...

I always thought sativa dominted strains flowered better under less intense as indicas? Or was it that sativas just worked better under less quality light?

 

[romanoweed]

your indoor Lights are anyway possibly so different and artificial to sunlight that this is probably too overkill i just assume.

tropical plant need watts