Autoflowering tropical Sativas (NLD)

[Donald Mallard]

which allows adaptation to different latitudes continuously, with critical photoperiods ranging from 12 hours to 18 hours or more.

i think this is yet to be seen ,
i saw the trait in zamal , and have seen it in other tropical sativas ranging back some time ,
but im not so sure they were able to adapt to latitudes out of the tropical zone so easily , if at all ,
maybe im missing something with what you said , if you would like to elaborate further ??

what i saw was not true flowering , just that they showed a heavy set of pre flower , in hours longer than 12/12 , up to 18/6 ,
it would be interesting to find what method would reset the plant in order to stop it ,
ie a root prune , repotting , heavy pruning ,, etc

 

[kendermag]

i think this is yet to be seen ,
i saw the trait in zamal , and have seen it in other tropical sativas ranging back some time ,
but im not so sure they were able to adapt to latitudes out of the tropical zone so easily , if at all ,
maybe im missing something with what you said , if you would like to elaborate further ??

what i saw was not true flowering , just that they showed a heavy set of pre flower , in hours longer than 12/12 , up to 18/6 ,
it would be interesting to find what method would reset the plant in order to stop it ,
ie a root prune , repotting , heavy pruning ,, etc

I have not explained myself well... I was referring to the fact that the highly variable critical photoperiod is what allows cannabis to thrive in such different latitudes, let's say from 0º to 60º latitude.

Nor did I mean that adaptation is quick or easy, but rather that it takes time, numerous generations.

Landraces or wild varieties have different critical photoperiods (CP), the most equatorial ones have a CP close to 12 hours, and the most northern ones, 15 hours or even 18 hours.

The average CP of cannabis may be 14h or 14.5h.

Within the same relatively stabilized variety, there may possibly be slight variations in CP.
But it could be these slight variations that allow adaptation... for example, if you plant thousands of seeds of an equatorial sativa landrace at a latitude of 60º, I understand that only a few, those with the highest CP, would produce seeds before frost. But with the passing of generations, they would probably already have a high CP (18h) and would be adapted to that latitude.

This is what I meant about adaptation.

On the other hand, I think that with a photoperiod close to the CP, the plants begin to develop pistils.
If the photoperiod is only slightly below the CP, the transition to flowering is slower. It would be like exposing a plant to 14h, its transition to flowering is slower than exposing it to 12h, and therefore flowering is longer.

For this reason, an equatorial sativa flowers faster with photoperiods of 10 hours or even less.

I also think that the CP is only one factor, the maturity of the plant also influences, or that it does not have space for the roots, the temperature and etc.

 

[gorilla ganja]

On the other hand, I think that with a photoperiod close to the CP, the plants begin to develop pistils.
If the photoperiod is only slightly below the CP, the transition to flowering is slower. It would be like exposing a plant to 14h, its transition to flowering is slower than exposing it to 12h, and therefore flowering is longer.

I agree with this.

The average CP of cannabis may be 14h or 14.5h.

I think you could be a little high on this, though. I would guess 80 % of cultivars, not including autoflowers, would flower between 12-13.5 hours CP. That's why most indoor growers use 12hrs, which works for probably 90%+ of cultivars.

 

[kendermag]

I think you could be a little high on this, though. I would guess 80 % of cultivars, not including autoflowers, would flower between 12-13.5 hours CP. That's why most indoor growers use 12hrs, which works for probably 90%+ of cultivars.

You're probably right. As usual, there is little literature about recreational cannabis...

There are some quotes about hemp's CP:

"It is necessary to determine critical photoperiods for different genotypes because they are dependent on the latitude of origin (Clarke, 1999; de Meijer and Keizer, 1994). For Thai hemp, critical photoperiods of 11.0 to 12.0 h have been reported (Sengloung et al., 2009). Cannabis with French origins has a critical photoperiod between 14.0 and 15.5 h (Struik et al., 2000). Mediterranean hemp has a critical period between 14.4 and 14.9 h (Cosentino et al., 2012)."