The DIF and Internode Elongation


New member
"The term DIF refers to the difference between the average day and night temperature and is calculated as:

DIF = day temperature – night temperature

The difference between the day and night temperature can influence internode elongation and thus stem extension. Stem elongation is promoted when the day temperature is warmer than night temperature (positive DIF). During the opposite environmental conditions, when day temperature is cooler than the night temperature (negative DIF), stem elongation is inhibited. A zero DIF refers to conditions where day and night temperatures are equal.

Knowledge of how DIF affects stem elongation can be used to regulate plant height. For example, plants grown at a day temperature of 68°F and a night temperature of 50°F (+18°F DIF) will have a taller finished height than plants grown at a day temperature of 68°F and a night temperature setpoint of 77°F (−9°F DIF) ( Figure 2). An intermediate height response would occur if these plants were grown at a day and night temperature of 68°F (0 DIF)."

Found at

I remember seeing an article on this in HighTimes but have always been reluctant to trust their sources. Anybody have any experience with this technique as it relates to cannabis?


Active member
Thanks for the moment of clarity!
I stumbled on this thread trying to find out why 10k kelvin can be used as a finisher.
It's always boggled my brain why flipping back to the opposite end of the spectrum is beneficial(and how ?)
being that the less kelvin is typically recommended for flowering phase.
The info you've provided will be applied to my current indoor project using hazes and higher uvb in trying to
eliminate stretch, increase stomata size.
"Cannabis uses malonyl-CoA to make Olivtol, which it in turn uses to make THC."