Different Light Cycle for Flowering Sativa?

After many years of first-hand experience breeding herb indoors as well as outdoors, I am of the opinion that the two most influential factors involving phenotypic variation and expression among current indoor herb breeding projects are the photoperiod (hours of light per day) and the angle of light in relationship to the growing plant.

Specifically, I find the single most powerful influence to the Indica dominant phenotype is the traditional 18/6 veggie cycle and 12/12 flowering cycle. The 18/6 veggie and 12/12 flower cycle is an attempt, however poor, to mimic the Indica-producing photoperiod. It is my belief that this light cycle strongly influences for Indica phenotypic expression.

Sativa phenotype characteristics will manifest under a more equatorial photoperiod, closer to a 13/11 veggie cycle and an 11/13 flower cycle. This is the light timing range to use to elicit more Sativa dominant expression from your plants.

As for the exact photoperiod formula that I incorporate into my growing/breeding regime, this will presently remain a trade secret. My advice is to experiment with different photoperiods, keep good notes and pay attention. Avoid the 18/6 and 12/12 photoperiods, while tweaking the times a bit differently with each breeding cycle until more desirable results in the finished product and their offspring are noted. Here's a hint: work in half-hour increments or a little less, and good luck!

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alaskalive said:

@ Snype
Yes, the article was from here...http://forum.grasscity.com/advanced-growing-techniques/220103-inducing-sativas-photoperiod-light-angles.html

Also, I recently got a copy of the new Cannabis Encyclopedia.. it talked briefly about this light cycle differing for Sativas... Link to that new encylopedia... http://www.amazon.com/The-Cannabis-Encyclopedia-cultivation-consumption/dp/1878823345 I would have to look up the page for reference.. just thought I would mention it in this awesome forum.. see what Experienced Growers would say.

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alaskalive said:

Also, I recently got a copy of the new Cannabis Encyclopedia.. it talked briefly about this light cycle differing for Sativas... Link to that new encylopedia... http://www.amazon.com/The-Cannabis-Encyclopedia-cultivation-consumption/dp/1878823345 pg. 90-91
I would have to look up the page for reference.. just thought I would mention it in this awesome forum.. see what Experienced Growers would say.

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alaskalive said:

I read in a book on MJ growing that Sativas put out much heavier yields if the light cycle in flower is not 12/12...
Anyone out there have any insight into this?

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PetFlora said:

Keep in mind sats are equatorial, where seasonal light does not change (spring- fall) like it does for indicas. IMO, this bio-clock is within the cannabis dna

I find when growing sats that they will take forever at 12/12. I usually keep it there for ~ 4 weeks, then back off by 15 minutes (Which I just did), which doesn't seem like much to us, but to the plant, it's a strong life ending signal. The last ~ 3 weeks I drop it another 15 minutes

Click to expand...

PetFlora said:

Keep in mind sats are equatorial, where seasonal light does not change (spring- fall) like it does for indicas. IMO, this bio-clock is within the cannabis dna

I find when growing sats that they will take forever at 12/12. I usually keep it there for ~ 4 weeks, then back off by 15 minutes (Which I just did), which doesn't seem like much to us, but to the plant, it's a strong life ending signal. The last ~ 3 weeks I drop it another 15 minutes

Click to expand...