VPD for flower ? Help

W

Wzrdovoddz

Member

Jan 27, 2020

• #1

Hey,

Does anyone know if the VPD is different for flowering as opposed to veg ? And if so what the VPD chart for flowering ? Thanks

 

twalte

Well-Known Member

Jan 27, 2020

• #2

hope this answers your question.

 

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W

Wzrdovoddz

Member

Jan 27, 2020

• #3

twalte said:

hope this answers your question.

Click to expand...

It absolutely does. Thank you

 

JohnDee

Well-Known Member

Jan 27, 2020

• #4

Wzrd,
I'm a fairly low tech guy...but to use vpd accurately...you need an infrared laser meter to measure leaf temp. The temp scale in the chart you just downloaded is probably leaf temp and not room temp. Hell...I'm not even sure it matters...but thought i'd mention it.
JD

 

W

Wzrdovoddz

Member

Jan 27, 2020

• #5

Wouldn’t leaf temp be pretty close to room temp ?

 

JohnDee

Well-Known Member

Jan 27, 2020

• #6

Wzrdovoddz said:

Wouldn’t leaf temp be pretty close to room temp ?

Click to expand...

Pretty close...if that's what you're shooting for. Remember infrared from HIDS heats up leaves...so I'm guessing they used leaf temp for a reason
JD

 

greg nr

Well-Known Member

Feb 7, 2020

• #7

The chart is assuming leaf temp 5 degrees cooler than room temp. It will be different for led.

Remember transporation (evaporation) is a cooling process so the leaf will be cooler than the room. Under hid, there is lots of infrared so the leaf temps will be higher.