An experiment to help determine the effect of different latitude on maturation time using a select cultivar

[Old Piney]

Hi folks Back in December a few of us had a decision going about how the maturation time of a select cultivar would vary grown at different latitudes. At first it was my position was that plants grow at higher latitudes would mature sooner, responding to the rapidly shorting days. Gorilla ganja disagreed with with me , arguing that that although the day light drops faster up north they starts from much longer days and have way further to go . After pondering this I revamped my prediction beleving it would be a wash and the plants would mature at about the same time. I suggested that this would be a great experiment and that all we need is two folks growing the same cultivar at different latitudes. Gorilla ganja took me up on it and offered a cultivar he had to use. His cultivar is a hybrid that expresses about half auto phenos, but for our experiment we are only be using the photoperiod plants .gorilla ganja is at 55 degrees north and I'm at 40 degrees north. I would love to get some feedback from you all with predictions before our results are finalize. Also if any one can direct us to a study on this already done that would be great. Here's a picture of miss k gorilla ganja’s hybrid

 

[Captain Red Eye]

I'm unclear. Are you guys using clones from the same plant or different plants but same cultivar / "strain" ?

 

[Old Piney]

I'm unclear. Are you guys using clones from the same plant or different plants but same cultivar / "strain" ?

Clones would be ideal but we are just using the same strain. I believe the photo period phenos are quite stable with maturation time. I grew out Two females and they are identical with timing

 

[pipeline]

Sweet! Was wondering about this. Obviously the frost is earlier in the north, but do the plants tend to finish earlier in the North than the south? I would think they would finish earlier because daylight would cut off earlier.

The angle of the sun becomes lower especially after September 21, the first day of autumn.

May be able to check the sunrise and sunset times at various dates to determine how they compare and how each location is changing week to week over time. May begin to help find an answer, but the best way is to grow out clones or stable phenotype strains.

 

[goingrey]

The microclimate will play a part as well. Shorter days might speed up flowering but cold temps will slow down everything.

 

[goingrey]

Also if any one can direct us to a study on this already done that would be great.

Some pretty early research referenced in this paper unfortunately the source doesn't seem to be digitized

Between 1912 and 1914, Julien Tournois worked on hops (Humulus sp.) and Cannabis [short-day plants (SDP)] and concluded that shorter daylength can accelerate their flowering (Tournois, 1914).

A Daylength Recognition Model of Photoperiodic Flowering

The photoperiodic flowering pathway is crucial for plant development to synchronize internal signaling events and external seasons. One hundred years after photoperiodic flowering was discovered, the underlying core signaling network has been elucidated ...

www.ncbi.nlm.nih.gov

Some more recent research:

Development of a hemp (Cannabis sativa L.) simulation model 2.The flowering response of two hemp cultivars to photoperiod

The duration from sowing to flowering is an important determinant of fibre yield potential in hemp, since maximum stem yield occurs shortly after flowering. As a short-day plant, daylength has a key influence on the timing of flowering in hemp. This paper reports on studies into the effect of...

www.publish.csiro.au

 

[kro-magnon]

Hi folks Back in December a few of us had a decision going about how the maturation time of a select cultivar would vary grown at different latitudes. At first it was my position was that plants grow at higher latitudes would mature sooner, responding to the rapidly shorting days. Gorilla ganja disagreed with with me , arguing that that although the day light drops faster up north they starts from much longer days and have way further to go . After pondering this I revamped my prediction beleving it would be a wash and the plants would mature at about the same time. I suggested that this would be a great experiment and that all we need is two folks growing the same cultivar at different latitudes. Gorilla ganja took me up on it and offered a cultivar he had to use. His cultivar is a hybrid that expresses about half auto phenos, but for our experiment we are only be using the photoperiod plants .gorilla ganja is at 55 degrees north and I'm at 40 degrees north. I would love to get some feedback from you all with predictions before our results are finalize. Also if any one can direct us to a study on this already done that would be great. Here's a picture of miss k gorilla ganja’s hybrid View attachment 19050778

Interesting experiment, curious to see the results in the different latitudes. Elevation could also have an impact as well, what do you think?
Good luck with this, keep us updated with the evolution of the plants.

 

[GreenestBasterd]

Great idea and interested to see the outcome!

What are the genetics of the strain you are both using?

 

[zaprjaques]

subbed good luck with your endeavors!

 

[mr.brunch]

Good experiment
i think it used to be said that maturation delays a week by every 1° further north

All the best

 

[Rodehazrd]

I’m subbed.Great question OP .

 

[Old Piney]

Thank everyone for your interest I will be posting up some pictures and early results latter today

 

[Old Piney]

Great idea and interested to see the outcome!

What are the genetics of the strain you are both using?

It's @gorilla ganja’s I believe he said it was a kush x Durban auto

 

[Old Piney]

The microclimate will play a part as well. Shorter days might speed up flowering but cold temps will slow down everything.

Good point. My plants are just in the ground and gorilla ganja’s are in his buddies greenhouse .He's grown them just outside so he should be able to tell us the difference in maturation time between the two

 

[Old Piney]

Elevation could also have an impact as well,

Another good point goes with the microclimate

 

[pipeline]

GIF animation of satellite imagery during sunrise.

 

[Old Piney]

Sweet! Was wondering about this. Obviously the frost is earlier in the north, but do the plants tend to finish earlier in the North than the south? I would think they would finish earlier because daylight would cut off earlier.

The angle of the sun becomes lower especially after September 21, the first day of autumn.

May be able to check the sunrise and sunset times at various dates to determine how they compare and how each location is changing week to week over time. May begin to help find an answer, but the best way is to grow out clones or stable phenotype strains.

Nice! A prediction that's what I'm talking about ! I was thinking like you but gorilla ganja makes the point that during the summer solstice they are much longer up north so they have further to go

 

[kendermag]

Hi folks Back in December a few of us had a decision going about how the maturation time of a select cultivar would vary grown at different latitudes. At first it was my position was that plants grow at higher latitudes would mature sooner, responding to the rapidly shorting days. Gorilla ganja disagreed with with me , arguing that that although the day light drops faster up north they starts from much longer days and have way further to go . After pondering this I revamped my prediction beleving it would be a wash and the plants would mature at about the same time. I suggested that this would be a great experiment and that all we need is two folks growing the same cultivar at different latitudes. Gorilla ganja took me up on it and offered a cultivar he had to use. His cultivar is a hybrid that expresses about half auto phenos, but for our experiment we are only be using the photoperiod plants .gorilla ganja is at 55 degrees north and I'm at 40 degrees north. I would love to get some feedback from you all with predictions before our results are finalize. Also if any one can direct us to a study on this already done that would be great. Here's a picture of miss k gorilla ganja’s hybrid View attachment 19050778

Very interesting experiment!
In my opinion, although there are many variables, I believe one of the most important is the critical photoperiod (CP)
Equatorial varieties have a CP close to 12h, and others from higher latitudes around 14h. Some semi-autoflowering varieties have it for 18 hours.

If, for example, the CP of your variety is 14h, at a latitude of 40ºN it should begin to flower at the beginning of August, which is when daylight lasts 14 hours.
At a latitude of 55ºN it should do so 15-20 days later, at the end of August.

Then I think we would have to add the flowering time, which under equivalent conditions, should be similar.

The climate is also important, I understand that the cold slows development.
Altitude is also related in this sense, the higher it is, the colder it is.

I'm also not sure how this affects, as well as the different number of hours... perhaps it affects size and production more than the total flowering time...

 

[Old Piney]

Very interesting experiment!
In my opinion, although there are many variables, I believe one of the most important is the critical photoperiod (CP)
Equatorial varieties have a CP close to 12h, and others from higher latitudes around 14h. Some semi-autoflowering varieties have it for 18 hours.

If, for example, the CP of your variety is 14h, at a latitude of 40ºN it should begin to flower at the beginning of August, which is when daylight lasts 14 hours.
At a latitude of 55ºN it should do so 15-20 days later, at the end of August.

Then I think we would have to add the flowering time, which under equivalent conditions, should be similar.

The climate is also important, I understand that the cold slows development.
Altitude is also related in this sense, the higher it is, the colder it is.

I'm also not sure how this affects, as well as the different number of hours... perhaps it affects size and production more than the total flowering time...

Nice! That sheds some light on things.Have no clue how equatorial stains even flower and to add to the confusion they have crops for almost all seasons

 

[Brother Nature]

Cool thread..