End of flowering light cycle 10/14?

[luckyduck69]

I've seen a few ppl talking about cutting the light cycle as far as 10 on 14 off the last couple weeks of the flowering phase and also turning down the light intensity, though it makes sense because that's what would happen in nature, but what my real question is, does it affect yield, the last couple of weeks are when they really fatten and harden up all for the sake of more terps? Has anyone tried this and been happy with the results, using less power for a couple of weeks would definitely be a bonus these days but not if it's at the expense of extra yield.

 

[Emilya Green]

Hi @luckyduck69 and welcome to the forum!
Sure, logic tells you that there would be less yield with less light input. The plant by this time has set up for the end and has been building strongly. This path has been set and the plant will continue on, but with slightly less light intensity... I myself reduce by about 20%, but don't always reduce the daytime period. I seriously doubt that either of us are going to lose much in extra plant growth and the buds will still swell and harden. They will also do it faster than if the light had not been reduced, and with less damage to the trichomes. I think the plant makes up for any leaf matter that might not be growing in the reduced light by producing more resin and trichomes... maybe adding to the weight overall.

 

[Buds Buddy]

Haven't ever tried this & I'm flowering now.... so here goes nothing.... lol. May as well try it for myself.
Great question @luckyduck69 & a very good answer @Emilya Green . Thanks to both of you !

 

[stinker]

A few grows ago I had a few plants that wouldn't fully mature. Eventually I added a couple xtra hrs of dark and they started to finish out. I don't think it affects yield as they fatten as they finish, adding the dark helps speed them along I think. In this indoor environment there is so little change. What are the triggers?
I learn by seeing what works and started adding more dark hrs to help along any late finishers in the tent. It helps.

 

[Dwight Monk]

I never noticed any difference, but then rare for me to grow same Strain twice or off Clones of the last batch as Cloning gave me issues after first couple times of working. Shorter light time and cooler temps seem to speed them up but more in the days not weeks, as they think winter coming fast and they still trying to breed. After first couple of grows I usually go under 12 on unless I need the heat as I was growing out in my shed outside, usually do a 10 on but sometimes 11. Seems to vary on the Strain slightly too, but limited amount of grow experience as I started in 2016.

 

[luckyduck69]

Hi @luckyduck69 and welcome to the forum!
Sure, logic tells you that there would be less yield with less light input. The plant by this time has set up for the end and has been building strongly. This path has been set and the plant will continue on, but with slightly less light intensity... I myself reduce by about 20%, but don't always reduce the daytime period. I seriously doubt that either of us are going to lose much in extra plant growth and the buds will still swell and harden. They will also do it faster than if the light had not been reduced, and with less damage to the trichomes. I think the plant makes up for any leaf matter that might not be growing in the reduced light by producing more resin and trichomes... maybe adding to the weight overall.

Hi Emilya and thank you.
Sounds good and my trichs are almost all milky, so about 2 weeks from harvest give or take, i've reduced the light to 11/13 this week and will do 10/14 next week and will reduce the intensity in light the last week on the led side as hps side would be a reduction of 40% min setting and be a bit much to chance to see if it works or not, proof of the pudding as they say. i'll keep a record what happens this time and next flowering cycle i'll stick to 12/12 with just light intensity reduction and compare the 2. Also makes sense that it won't affect yield if they speed up because they think winter's coming, cheers for the input

 

[luckyduck69]

Haven't ever tried this & I'm flowering now.... so here goes nothing.... lol. May as well try it for myself.
Great question @luckyduck69 & a very good answer @Emilya Green . Thanks to bothchers Buds

Cheers Buds, im at the end of flower myself and will let you know if i think it helped, if it finishes at the same speed with less light/power being used it will be worthwhile with that alone.

 

[luckyduck69]

A few grows ago I had a few plants that wouldn't fully mature. Eventually I added a couple xtra hrs of dark and they started to finish out. I don't think it affects yield as they fatten as they finish, adding the dark helps speed them along I think. In this indoor environment there is so little change. What are the triggers?
I learn by seeing what works and started adding more dark hrs to help along any late finishers in the tent. It helps.

good to hear you think it helps and speeds things along, I've a couple lavender Kush that's about 1 week behind everything else, hopefully will help them catch up with the rest.

 

[luckyduck69]

I never noticed any difference, but then rare for me to grow same Strain twice or off Clones of the last batch as Cloning gave me issues after first couple times of working. Shorter light time and cooler temps seem to speed them up but more in the days not weeks, as they think winter coming fast and they still trying to breed. After first couple of grows I usually go under 12 on unless I need the heat as I was growing out in my shed outside, usually do a 10 on but sometimes 11. Seems to vary on the Strain slightly too, but limited amount of grow experience as I started in 2016.

Even with different strains in, i keep a tight eye on the trichs and should be able to tell roughly if it's helped or not. u should look into zibro paraffin inverter heaters if you've cool temps, easy to run, mine has been on normal heating oil for years no problem, have thermostat and timer with no light pollution, was an essential addition to my grow room.

 

[bluter]

i've run diminishing schedules loads of times. 12/12 - 11/13 - 10/14. particularly useful with sativas. i don't reduce the intensity though, you also need piles of light to do it well.

 

[Sativa1970]

Reducing light has two effects.

Leaves have 2 functions. Photosynthesis to create glucose and also to store the glucose. When you "flush" it forces the plant to use up stored glucose without the ability to readily make more. Reducing light has a similar effect just limiting the other half of the equation. I have found flushing makes no difference in the smoke if you cut the lights.

The plant lives for the one purpose of procreation. When you trigger a late season response it will go into a panic mode and will do anything it can as a last ditch effort to catch pollen. All of it's stored energy is sent to the flowers. I turn my lights down just a bit and/or lift them up for the last 4-7 days. I don't change number of hours because I have several plants in the flower room at different stages. Every time I turn down the lights, the next "day" my wife comments on the sudden strong smell. Never need to tell her I adjusted lights for harvest. fortunately she likes the smell.

As Bluter mentioned, it is more noticeable in my land strain sativas than my sativa dominant hybrids. I don't remember it being as noticeable with indica, but I haven't grown any indica in almost a decade. In nature the length of day change is subtle in equatorial satvas but light intensity changes with season.

 

[luckyduck69]

Reducing light has two effects.

Leaves have 2 functions. Photosynthesis to create glucose and also to store the glucose. When you "flush" it forces the plant to use up stored glucose without the ability to readily make more. Reducing light has a similar effect just limiting the other half of the equation. I have found flushing makes no difference in the smoke if you cut the lights.

The plant lives for the one purpose of procreation. When you trigger a late season response it will go into a panic mode and will do anything it can as a last ditch effort to catch pollen. All of it's stored energy is sent to the flowers. I turn my lights down just a bit and/or lift them up for the last 4-7 days. I don't change number of hours because I have several plants in the flower room at different stages. Every time I turn down the lights, the next "day" my wife comments on the sudden strong smell. Never need to tell her I adjusted lights for harvest. fortunately she likes the smell.

As Bluter mentioned, it is more noticeable in my land strain sativas than my sativa dominant hybrids. I don't remember it being as noticeable with indica, but I haven't grown any indica in almost a decade. In nature the length of day change is subtle in equatorial satvas but light intensity changes with season.

i've cut the intensity and 1 hr less last week and might keep it at that till harvest to see if i think there's much difference, makes sense what you're saying as to where a plant grows closer to the equator, the daylight hrs doesn't change much, mine are mainly indica dominant so lowering light intensity should do the trick, hopefully.

 

[bluter]

i've cut the intensity and 1 hr less last week and might keep it at that till harvest to see if i think there's much difference, makes sense what you're saying as to where a plant grows closer to the equator, the daylight hrs doesn't change much, mine are mainly indica dominant so lowering light intensity should do the trick, hopefully.

do one or the other but not both. it's important to understand for a diminishing schedule to work, you need to be over lit for the size of the space.

in other words, if you have enough rig and intensity for a 5x5, that would work for a diminishing schedule if you are in a 4x4 or 3x3, but not in the 5x5 itself.

 

[Sativa1970]

Light reduction is fasting for the plant. If it is healthy and has reserve glucose it will burn it to the finish line. Reducing the harsh chlorophyll and plumping buds. A week plant or starting too early will hamper the plant. It will run out of energy before the finish line.

There have been vary few scientific studies on cannabis specifically but you can assume it is similar chemistry to similar plants. When the light reduces you get the fall effects. Chlorophyll is broken down and scavenged from the plant. Glucose is stripped from the chlorophyll with a byproduct of ethylene. Annuals use the glucose toward flower/seed production. Perennials store it for next years leaf production. Ethylene is gassed off through flowers and/or "green" fruit. This promotes rapid ripening. If you have ever left green bananas in a paper bag to find over ripe fruit the next day, you have seen the effect of the Ethylene gassing off.

 

[luckyduck69]

2 weeks complete of reduced intensity and no notable changes than normal, by eye at least, trichs took same time to change milky/amber, will see if any after drying and curing.

 

[bluter]

2 weeks complete of reduced intensity and no notable changes than normal, by eye at least, trichs took same time to change milky/amber, will see if any after drying and curing.

what were you running for light ?
were you able to add enough in to hit the correct DLI with the reduced intensity or did you pay that any attention ?

 

[luckyduck69]

what were you running for light ?
were you able to add enough in to hit the correct DLI with the reduced intensity or did you pay that any attention

what were you running for light ?
were you able to add enough in to hit the correct DLI with the reduced intensity or did you pay that any attention ?

i was able to cut the LED by roughly 20% and the hps by 40% as this is the only ballast dimmer switch setting, though i lowered the shade to compensate and hopefully reduced the 40% closer to 20/30%, do you drop light intensity yourself?

 

[bluter]

do you drop light intensity yourself?

i often run a diminishing schedule in flower but generally leave the intensity in the 80 - 90% range.

 

[luckyduck69]

i often run a diminishing schedule in flower but generally leave the intensity in the 80 - 90% range.

Unfortunately, i can only do that with the LED light, do you notice any benefit? Someone said it works better on sativas, maybe this is why i didn't notice much difference but does no harm trying out new things to see what works.

 

[bluter]

Unfortunately, i can only do that with the LED light, do you notice any benefit? Someone said it works better on sativas, maybe this is why i didn't notice much difference but does no harm trying out new things to see what works.

it can speed flower up a bit with little to no loss of production. it works for both indica and sativa but you'll notice the shorter flower time on long running sativas more than you would an indica.

i've ran some with 120 day flower times and it cut a good 2 wks or more out.