VPD and Leaf Temperature

[ACannabisCritic]

The VPD charts that I have seen do not consider leaf temperature.

There is anecdotal evidence that the difference between garden air temperature and leaf temperature can be as much as +/- 10F from one grow to another depending in large part on the amount of infrared energy coming from grow lights.

My point here is that several different grows can have the same VPD, but drastically different water vapor pressure (WVP) differences between the leaf's stomata and the air.

I have been looking at the WVP of the leaf (leaf temperature at 100% saturation) and its relationship to the WVP of the air. I think there may be a useful ratio in these numbers that could translate to variable environments.

I would like to ask some of you to help me gather some data. I need just enough to convince me there might be a hypothesis that could be tested.

I welcome your comments and questions...Jeff

 

[exploziv]

I grow under leds. As I have what I call more than enaugh ventilation and air movement I have never worried about this. But now that you mention it, next time I visit the plants will check leaf temp as well. I have an infrared termometer for that.
May I ask what difference you observed in the relationship between leaf temp and air temp under leds versus under hids? Any info on this?
Will report my measurements once I take them.

 

[Ibechillin]

In the lighting thread in my signature there is a good amount of information on LST.