I would really like to know how defoliating affects VPD. Especially as its a common practice said to increase yields. Leaves are important for so many things so im just wondering why this practice is said to do this.
Here's an easy way to understand what VPD is as a concept if you had trouble with this video. Relative humidity is a percentage because it's the ratio of how much moisture the air contains compared to how much it CAN hold at the current temperature. VPD is basically the other side of that coin – it's a measure of how much MORE moisture the air can hold at a given temperature.
Thanks for this now as a person like me a beginner grower I w I uldhave to get a instrument to use the VPD CHART? Is there another way I can do this if I Need,? If I can't equipment? And again thanks for this lesson #YouDig
Sorry but she doesnt know what she is talking about when it comes to botrytis. Seems like she thinks its just passive mold growth on stressed plants. No, if you have a susceptible variety and inoculum in your growing area, following the vpd curve wont magically protect your plants. Its generally an okay guideline (recommends around 50 percent humidity in warm conditions.) I would say go down to 40 in the last 2 weeks. Saving some on your hvac bill isnt worth losing a full crop due to testing positive to botrytis.
Not a word about leaf surface temps, which is a major factor of VPD. Think of a triangle, where you have to keep 3 factors constant within a parameter- air temp at top of canopy Relative humidity at top of canopy leaf surface temp at top of canopy you are looking to maintain 1-2 degC cooler leaf surface(LST) than ambient. Everything can look fine in the numbers if you ignore LST, but maybe little growth.. then you check LST and find it is 5-6 degC below ambient, then you realise why LST is also on the VPD chart along with air temp & RH.
Vpd is scary for cannabis for sure. Finding the happy middle. I like my humidity 55% but temps in mid to high 70s. If I get over 65% I worry and when lights shut off the the humidity should stay below the temp as if it goes above the temp that can cause issues. Juggling the VPD take the proper equipment and can be expensive on a large scale. Humidifiers dehumidifiers a/c and heaters etc are all needed to keep your humidity in check
"Do people know about VPD?" What kinda question is that? What amount of quality information can be derived from such an arbitrary question? Her response to that alone consumed 2.5 minutes of your video!
Her response in a nutshell: Yeah sure, but lets educate 'em some more.
Ah.. thank you very much for sharing this knowledge to every one.. i have been playing with vpd in my grow tent for a year now.. i have better understanding now..
Thank you for the knowledge drop I live in canada and in the winter I have a hard time keeping rh over 25 % and definitely noticed a nutrient deficiency I think it's time to get a good humidifier and if I understand right around 50 % rh at 70 degrees Fahrenheit should shock the plants less ??
Hello, could negative pressure ventilation (in a grow room or tent) influence VPD ? Could there be relations between the two we could control ?
I would really like to know how defoliating affects VPD. Especially as its a common practice said to increase yields. Leaves are important for so many things so im just wondering why this practice is said to do this.
🤔
0.50 literally…. not really
Good info although i was hoping for more numbers?
So, when she says "VPD is low", doesn't it mean "VP" is high?…
So just add humidity?
Here's an easy way to understand what VPD is as a concept if you had trouble with this video. Relative humidity is a percentage because it's the ratio of how much moisture the air contains compared to how much it CAN hold at the current temperature. VPD is basically the other side of that coin – it's a measure of how much MORE moisture the air can hold at a given temperature.
Hello! 😀
People like Nadia: 10/10. Next level West Coast growers: 10/10. This video as useful educational material: 4/10.
Thanks for this now as a person like me a beginner grower I w I uldhave to get a instrument to use the VPD CHART? Is there another way I can do this if I Need,? If I can't equipment? And again thanks for this lesson #YouDig
Wow amazing video thank you very helpful
Sorry but she doesnt know what she is talking about when it comes to botrytis. Seems like she thinks its just passive mold growth on stressed plants. No, if you have a susceptible variety and inoculum in your growing area, following the vpd curve wont magically protect your plants. Its generally an okay guideline (recommends around 50 percent humidity in warm conditions.) I would say go down to 40 in the last 2 weeks. Saving some on your hvac bill isnt worth losing a full crop due to testing positive to botrytis.
Not a word about leaf surface temps, which is a major factor of VPD.
Think of a triangle, where you have to keep 3 factors constant within a parameter-
air temp at top of canopy
Relative humidity at top of canopy
leaf surface temp at top of canopy
you are looking to maintain 1-2 degC cooler leaf surface(LST) than ambient.
Everything can look fine in the numbers if you ignore LST, but maybe little growth..
then you check LST and find it is 5-6 degC below ambient,
then you realise why LST is also on the VPD chart along with air temp & RH.
Vpd is scary for cannabis for sure. Finding the happy middle. I like my humidity 55% but temps in mid to high 70s. If I get over 65% I worry and when lights shut off the the humidity should stay below the temp as if it goes above the temp that can cause issues. Juggling the VPD take the proper equipment and can be expensive on a large scale. Humidifiers dehumidifiers a/c and heaters etc are all needed to keep your humidity in check
"Do people know about VPD?"
What kinda question is that? What amount of quality information can be derived from such an arbitrary question? Her response to that alone consumed 2.5 minutes of your video!
Her response in a nutshell: Yeah sure, but lets educate 'em some more.
Ah.. thank you very much for sharing this knowledge to every one.. i have been playing with vpd in my grow tent for a year now.. i have better understanding now..
Great information very knowledgeable 🌟
NICE
Common sense would say osmotic pressure will have to be taken into consideration as well? How do the 2 relate??
Thank you for the knowledge drop I live in canada and in the winter I have a hard time keeping rh over 25 % and definitely noticed a nutrient deficiency I think it's time to get a good humidifier and if I understand right around 50 % rh at 70 degrees Fahrenheit should shock the plants less ??
when i did vdp my garden went to next level
spring in vermont can be interesting ………great video