How do I Manipulate the Photoperiod for Larger Yields

[SmokeyMacPot]

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]

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]

Originally Posted by zolar

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.

[gazan114]

i do this system after 10 weeks of flowering correct? or 2 weeks before harvesting?

[McBudz]

Originally Posted by gazan114

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.