After my first post about a photoperiod plant that flowered with 16 hours of light per day I’m going to test a few plants to see how much darkness they need to start flowering. When it happened I put the plant on 24 hours of light per day for a week (continuous light for a week) after it flowered when it shouldn’t have. Since then I have been reducing the light by 1 hour every 2 weeks and am down to 22 hours of light per day. I am just changing the timer by 1 hour in a one off event every 2 weeks.
Should I be reducing the light by 1 hour at a time or should I do it in 15 minute increments, or 30 minute increments?
Should I be reducing the light every 2, 3 or 4 weeks?
I am reducing the light by 1 hour every 2 weeks but maybe 3 weeks would be better because I will be able to see the plant start to flower before reducing the light any more.
You have made this way more complicated than it needs to be.
If this is truly an experiment then do you.
As for typical lighting practices there is no need to do any of what you are saying. Cannabis is a C3 plant which means it doesn’t need a dark period to live. BUT… it does need a dark period to metabolize stored energy from photosynthesis.
Most folks run 18/6 throughout veg for both Photo and Auto’s and some just let the autos continue through flower on that schedule, for us photo growers we have to drop to 12/12. You do not need to step down or up during the switch. Maintain proper DLI/PPFD for plant type and stage of growth and you will be fine.
Yes I know I’m over complicating it but I am a science geek as well as a gardener and sometimes things interest me. All the info I read said you just flip the plants to 12/12 light cycle and they flip, which is correct for photoperiod plants. However, after one of my plants flowered while getting 16 hours of light per day I am now interested in finding the actual times for my specific plants. If one flips at 16 hours and the other flips at 14 or 15 then I can get all excited over the numbers and try with other plants.
Strains from higher latitudes (not equatorial) or crossed to them (hate to use indica anymore) to crest hybrids will flower with just an abrupt drop in light I have found. Regardless if that’s down to 16 or 14 or 12 on. If you are going 20 or 24 on and drop it to 18 or 17 I sometimes see some preflowers form.
Equatorial strains ( hate to use sativas) will not flower unless they reach the 12 hour threshold. Sometimes just 11 on to really get them going into flower. At least this had been my experience.
Rather than explain the subtle differences to most growers whom would not ponder the implications, it’s easier to just make the standard operating procedure go to 12/12.
Those high lat ones that start to flower will go back into veg eventually if the days don’t continue to wane in hours of daylight. Interesting enough……
I’ve done what your thinking of doing my last grow.
I was running 18/6 and over 4 days time I reduced daylight 30 minutes in morning and another 30 minutes in evening just to better mimic nature.
When I got to 14 hours day and 10 hours dark I stopped. They all went into flower.
I’ve flowered many times running 14/10 for photos with no issues.
As mentioned earlier maintain the recommended daily light integral (DLI) based on stage they are in.
I’m always down for a good experiment, that’s how we learn right?
The amount of hours needed will be very strain and some pheno dependent.
This is actually a study big breaders use to determine stability and resilience for the general public. (Hours of darkness and light leakage allowance)
Glad you’re having fun with it.
