Douglas.C
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Vapor Pressure Deficit
Buzzword that was just hitting the forums a few years ago. Used to prevent moisture buildup on plant surfaces in greenhouses?
I remember the common chart being shown around. I checked my room environment against it back then and shrugged. Years later I come back to the forums and what do I see? 70% humidity and 80F+ room temps? Wow, talk about growing upside down for cannabis.
I'm sure VPD has it's place in cultivation, even for cannabis, but the chart folks are using is definitely wrong. At 72F it says 35% humidity produces 17.something VPD. I flower at 25-30% humidity, 35% lowers quality in my garden. So somewhere around 18+ VPD in my plants? Poppycock! Or, if it is 18+, cannabis loves it.
Here it is, years later, and my cannabis is even more trichome dense than ever. Cannabis around me has gone downhill in quality (or just stayed the same??). This sucks for people using cannabis, and this VPD stuff has a lot to do with it. Every time I hear about a grower complaining about how hot it is in their flower room, I cringe. Every time someone hands me a bowl of "their best," I gag or feel the burn.
Cannabis LOVES 72F and 25% humidity during flower. Or it could be that it hates it, either way it responds by increasing the number of trichomes per square inch. Terpene and cannabinoid production are amazing, I can't wait to get my next harvest tested.
Keep in mind that these conditions need to be present BEFORE you initiate flowering, the density of the trichome coverage is pretty much set at the beginning of flower. At least as far as I've noticed.
Anyone else found the joys of low temp, low humidity quality?
Douglas
Buzzword that was just hitting the forums a few years ago. Used to prevent moisture buildup on plant surfaces in greenhouses?
I remember the common chart being shown around. I checked my room environment against it back then and shrugged. Years later I come back to the forums and what do I see? 70% humidity and 80F+ room temps? Wow, talk about growing upside down for cannabis.
I'm sure VPD has it's place in cultivation, even for cannabis, but the chart folks are using is definitely wrong. At 72F it says 35% humidity produces 17.something VPD. I flower at 25-30% humidity, 35% lowers quality in my garden. So somewhere around 18+ VPD in my plants? Poppycock! Or, if it is 18+, cannabis loves it.
Here it is, years later, and my cannabis is even more trichome dense than ever. Cannabis around me has gone downhill in quality (or just stayed the same??). This sucks for people using cannabis, and this VPD stuff has a lot to do with it. Every time I hear about a grower complaining about how hot it is in their flower room, I cringe. Every time someone hands me a bowl of "their best," I gag or feel the burn.
Cannabis LOVES 72F and 25% humidity during flower. Or it could be that it hates it, either way it responds by increasing the number of trichomes per square inch. Terpene and cannabinoid production are amazing, I can't wait to get my next harvest tested.
Keep in mind that these conditions need to be present BEFORE you initiate flowering, the density of the trichome coverage is pretty much set at the beginning of flower. At least as far as I've noticed.
Anyone else found the joys of low temp, low humidity quality?
Douglas