i understand that this doesn't really answer your question but i thought that you might find it interesting and useful...
Low Maintenance Mothering
Stasis& Selective Light Intensity
Using clones of a favorite plant is the best way to perpetuate the traits we like most about that plant. It also helps bring some uniformity to a garden so we can rest assured that all the plants grow in the same manner and at the same rate. For the Sinsemilla cultivator one of the best things about using clones is that it removes the anxiety ridden step of sexing plants, eventually culling the males, then growing whatever females Mother Nature has seen fit to leave us with.
Unlike seeds, using clones requires a living plant from which cuttings can be taken. While cuttings can be taken from a crop destined to be harvested, many people don't want to compromise their producers and will designate a separate plant to be the mother for their next generation of clones. Because a vegetative phase is more conducive to taking cuttings, and generally used for rooting them, a separate space is set up to isolate plants receiving a flowering photoperiod from those receiving a vegetative photoperiod. The vegetative space occupied by the mother plant(s) will need to be maintained separately. Timing the plant's growth in such a way as to deliver enough cuttings, at the right time, and of a good quality is of the essence.
The need for cuttings develops as a crop nears harvest. Advance time must be allowed for the cuttings to root well so their placement in the system will coincide with the timely harvesting of the flowering plants. This means that a mother plant will be growing for almost the entire duration of a crop before her services are ever needed again. Under the wrong conditions this length of time (e.g. 60-90 days) can produce a mother plant that will easily outgrow its allotted space, or demand your time in order to maintain the growth within the space limitations. This hands-on maintenance usually takes the form of removing or redirecting growth. What's described here are two methods of
reducing growth so that the time spent using hands-on methods can be eliminated.
The Stasis Photoperiod
Vegetative photoperiods generally range from a constant 24 hours to 16 hours of light per day. Its goal is to prevent the plant from flowering, thus for mothers, providing good vegetative stock for cuttings. Needless to say 16 hours of light per day will produce less growth than more hours will, so for purposes of growth reduction fewer hours of light per day is preferable.
Because the flowering response of cannabis is triggered by the duration of the dark phase, it will flower when it receives 12 hours of
uninterrupted darkness, but it will not flower with 12 hours of
interrupted darkness. Manipulating light timer settings in such a way as to provide 12 hours of light over a 24 hour period, but not permitting 12 hours of uninterrupted darkness to occur, can reduce growth by 25% when compared to the traditional 16 hour vegetative photoperiod without triggering the flowering response. A timer capable of 4 on/off cycles per day, using the settings in the following table, will produce such results.
Timer settings for a 24 hour period
beginning at 7pm
ON
OFF
7 pm
6:00 am
9 am9:20 am1 pm1:20 pm4 pm4:20 pm (off til 7 pm)
As you can see from the below graphic, over a 24 hour period these timer settings will provide 12 hours of light and 12 hours of darkness, but will not trigger flowering because no single dark phase is long enough to do so.
The above are examples of one timer schedule that's known to work well, others are indeed possible.
Selective Light Intensity
Because a stasis photoperiod requires multiple on/off light cycles per day, it's best applied using fluorescent lighting, rather than stress HID lighting system components with so many daily on/off cycles. It also makes sense that if one wants to reduce growth that he would opt for lighting that provides fewer lumens. Unlike HID lighting, fluorescent lighting often uses multiple bulbs to distribute light over a given area. Configuring a multiple fluorescent lamp set-up so that each light can independently be turned on or off allows a grower to not only control the duration of the light per day with a stasis photoperiod, but to also control the light intensity.
Selective light intensity with fluorescents is nothing more than using as few tubes (less light) as needed to keep growth to a minimum during the times cuttings are not needed, and using more tubes (more light) just prior to taking cuttings so that shoots used for cuttings will be more robust and make for better clones. Turning off half of the available lamps during this time can reduce growth by 50%.
The combined growth reduction from using stasis and selective light intensity can approach 75%. The benefit is that the time spent on manual hands-on mother maintenance is replaced by the flick of a few switches.
