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How do I Manipulate the Photoperiod for Larger Yields

SmokeyMacPot

New Member
The only photoperiod manipulation from years of experiments that offered discernible improvements was this adjustment made for 1 or 2 calendar weeks at the point of maximum flowering rate: Daylength of 21 hours, 36 minutes with a dark period of 12 hours. To accomplish this, you need a 7 day, 24 hour digital timer. During a 7 day calendar week on Earth, the "sun" only cycles 5 times. This permits easily switching back to the regular 12/12 at your discretion. You may want to only alter during peak flower production to stimulate the plant's metabolism. Using this photoperiod throughout the flowering cycle will cause this:

A variety that takes 49 days of 12/12 to mature, won't see 49 - 12 hour dark periods under 21:36/12 until almost 10 calendar weeks have passed.

The total increase in light energy is almost 80%, which will produce larger yields, if all of your other enviromental conditions are kept optimal.

The total increase in flowering period is only 40%, half the potential room for improvement. This means you don't have to be perfect to win out.

Selective application of the 21:36/12 photperiod for only 1 or 2 weeks extends the wait only 2 to 4 Earth days, which makes up the missing 2 complete day and night cycles each week on Planet Ito. This permits the additional light energy to be provided without purchasing additional equipment or overloading existing circuits, which maximizes the existing system's capabilities. The main advantage is that matched with co2 and optimal nutrition, the plants metabolism will increase dramatically. I have only successfully tested this photoperiod for two weeks. The potential for a net increase of 40% over the entire cycle (80% increase in light energy vs. 40% longer wait) is worthwhile. Don't be afraid!

Day 1 - Sunday, 6:00am til Monday, 3:36am
Day 2 - Monday, 3:36pm til Tuesday, 1:12pm
Day 3 - Wednesday, 1:12am til Wednesday, 10:48pm
Day 4 - Thursday, 10:48am til Friday 8:24am
Day 5 - Friday, 8:24pm til Saturday 6:00pm

Author: MisterIto
 

zolar

New Member
i have used a darktime longer than 12 hours to speed up the changes from veg to flower cycle and have found documentation on some agrcultural websites by colleges on this type of manipulation effect on flower cycles common commercial applications poinsettas
easter lilies bedding plants
 

McBudz

Nug of the Month: Oct 2008
i have used a darktime longer than 12 hours to speed up the changes from veg to flower cycle and have found documentation on some agrcultural websites by colleges on this type of manipulation effect on flower cycles common commercial applications poinsettas
easter lilies bedding plants

I was thinking about running this type of cycle (21:36/12)with my next batch of clones. I have a timer that will allow me to do this. If I decide to do it I will keep a journal. Keep an eye out in the next month or two. :peace:
 

McBudz

Nug of the Month: Oct 2008
i do this system after 10 weeks of flowering correct? or 2 weeks before harvesting?

I believe you would do this throughout the whole bloom cycle. It would still be the same amount of day night cycles a normal plant would see but the day period is longer giving more light and energy.

There is a new timer out that allows to you control the length of you day from 14 hours to 34..

Product Description
The Plug‘n’Grow 14-34-Hour Cycle Timer is perfect for gardeners who want their lights to automatically turn on and off in intervals other than the standard 24 hours. Timer regulates any 120-volt, 15-amp gardening gadget via an “on” cycle which can be set from eight to 18 hours and an “off” cycle that can be set from six to 16 hours, meaning growers can adjust the length of their plants’ “days” to anywhere between 14 and 34 hours! Includes a three-year manufacturer’s warranty and daily technical support.

PG112.jpg
 

Enso Boy

New Member
Ed Rosenthal says to start the flowering with 12/12 to force flower then go to 13.5 on/ 10.5 off to increase the yield...He also states that prime ripening will be extended an extra 1-2 weeks; so if you would normally chop at 10 weeks, expect it to go 11-12 weeks.
 

Cultivator

Member of the Month: Jan 2013 - Plant of the Month: Nov 2016, May 2018 - Nug of the Month: Mar 2018 - Creme de la Creme Photos: Oct 2016

SWGreenThumb

New Member
Hey I'm doing a lot of searching trying to figure out if the alternative photoperiod of longer days than nights but with still 12 hours of dark works...

Does anyone have any findings to report? McBudz? Several people mentioned trying it out but I don't see any posts on here saying how it worked... Anyone?

Thanks!
 

SWGreenThumb

New Member
I'm using LED's... I'm wondering if the longer days would help to get bigger buds out of these expensive lights? I was thinking of trying 18/12 or something...
 

willoby

New Member
I'm using LED's... I'm wondering if the longer days would help to get bigger buds out of these expensive lights? I was thinking of trying 18/12 or something...

I don't have any led lights but from what I have read up on almost all leds is that they are rated for a max of about 14-16 hours of light per lighting period. You may want to check with the manufacturer and ask so you dont end up with some really expensive lights that are broke down....I have been checking into it too cause I have Autoflowers that require 20hrs of lights and every led vendor I have spoke with doesn't recommend it for that long....Just a suggestion man.....check it out:goodluck:
 

SWGreenThumb

New Member
Interesting thoughts, willoby. So are you saying the lights might burn out after a while if left on for long periods of time? I haven't heard anything about this, but I am currently using my LED's for 24 hour lighting with no problems. They also come with a 3 year warranty so I'm not too worried about them breaking.

I'm not going to try the photoperiod manipulation just yet... I want to get it down normally first, then I'll fool around a little more.
 

sully508

New Member
i did 48 hours on and 24 off during flowering after 5 weeks. they totally exploded w/ bud.
i did this for 2 weeks to get try to see buds faster. then went back to 12/12 for weeks 8, 9 ,and 10 then went to 11 on 13 off for 2 weeks. ak48 from nirvana
i got 84 grams, 78, and 93 dried 3 plants, i did a 18/6 veg for 6 weeks.
im really not sure if it made a difference or not. but after doing the 48/24 the buds really bloomed.:goodluck:
 

Goldengoose7

Plant of the Month: Sept 2011, Nov 2012 - Nug of the Month: Oct 2012

A VERY intriguing idea and one that I would definitely like to try on my next flowering session that is coming up soon! That timer would certainly make it a lot easier to get the light and dark cycles right.

Just an FYI: This unique timer AIN'T CHEAP, and came out in August of 2010. Retail is $129.00 and the few sellers who are stocking it are asking full price PLUS shipping! :eek:(

Also.. when I Google this model I kept getting the model 011 which looks exactly the same, but does not offer these longer ON / OFF cycles. This one is the 011L not the 011 which sells for a lot less.

Be careful if you order one of these to make sure you are getting this version and not the cheaper cycle timer that uses the exact same chassis.

I'm still debating whether I want to drop $130.00 plus shipping on a new light timer. Unfortunately, my Intermatic 620CLs can't do these ON/OFF cycles. They are 24 hours only.
 

Goldengoose7

Plant of the Month: Sept 2011, Nov 2012 - Nug of the Month: Oct 2012
UPDATE: Bad news if you want one of these unusual light timers!

I have just learned that the 14-34 timer mentioned in this thread has been discontinued!

If you want something like this, best to call any retailer that lists it as being in stock, since if they have to order it for you, they will be told that the item is history!
 

Goldengoose7

Plant of the Month: Sept 2011, Nov 2012 - Nug of the Month: Oct 2012
I found one and ordered it! :high-five:

Looks to be the last new one available for sale in the USA, since I called every shop in a Google search that showed stock before I found a dealer that still had one in stock, and it was their LAST ONE. :welldone:

I want to try a 16/12 light cycle for flowering my Blueberry plants, and this timer will make it 10 times easier to do!
 

kdogsgirls

New Member
I read something that said once your like 2/3rds way through flowering, the plant will benefit from exyra lite..that its right in the point of maximum flower and a long day wont effectthe flowering but that the extra lite gives em more time to grow......total bull , a plant can be revegged after harvest so why wouldnt extra lite fuck it up.......im sticking fo twelve twelve...i worktoo hard at this to maybe fuck em up
 

Goldengoose7

Plant of the Month: Sept 2011, Nov 2012 - Nug of the Month: Oct 2012
When you start playing with this kind of stuff, you have to think outside the 24 HOUR Box!

Its the LENGTH of the DARK CYCLE, NOT the DayLight cycle that effects flowering. 12 hours or more of darkness promotes flowering irregardless of the day length.

I am fully planning to begin running a 14/13 on my Blueberry clones that are coming up on Week 3 of 12/12. I will be posting observations in THIS THREAD.

I've done a TON of reading up on this over the last few weeks, and I have ZERO worry of the plants going back to a reveg state.
 

kdogsgirls

New Member
So if they get 12 hours dark, then 14 hours lite they wont reveg? What if its eleven hourd dark? Reveg? Also id assume that it has to be done far enough into flower?
 
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