SQl2kGuy
Well-Known Member
Keep asking questions and reading journals ... there's a lot you can do for your plants.
Trust this chart?
- Thread starter Dinger
- Start date
Keep asking questions and reading journals ... there's a lot you can do for your plants.
Gazoo
Member
Yes the Leaf temp to Ambient DIFFERENCE is a key VARIABLE in the chart readings ALONG with the
GROW STAGE
I have been using the CHART above with the -2c readings BTW there is a -1c chart as well that I used
to calculate out the Difference for A ZERO leaf to ambient difference.
(Move the ANSWER 4 places to the right for zero difference)
Also found using HID & T5s I need canopy to be at 21 inches below HID for the -2c
Had the chart enlarged and printed at Kinkos just enough room to add the F readings
SQl2kGuy
Well-Known Member
Hey @Gazoo ... I'm glad you popped in and pointed that out.
I have been assuming that my leaf temperatures were around 2°C (4°F) below ambient. I'll buy the temperature gun one day though to do canopy readings.
Actually, this week when I let the canopy drop below 30 cm (12") ... the leaves hated it and started to curl.
Alright ... ttyl
SQl2kGuy
Well-Known Member
Yes the Leaf temp to Ambient DIFFERENCE is a key VARIABLE in the chart readings ALONG with the
GROW STAGE
I have been using the CHART above with the -2c readings BTW there is a -1c chart as well that I used
to calculate out the Difference for A ZERO leaf to ambient difference.
(Move the ANSWER 4 places to the right for zero difference)
Also found using HID & T5s I need canopy to be at 21 inches below HID for the -2c
Had the chart enlarged and printed at Kinkos just enough room to add the F readings
Now that was smart and comes in real handy!
Alright ... I think I have a bit more time to read some other threads today!
ttyl
Gazoo
Member
Yes I have always understood a HIGHER leaf Temp than AMBIENT is a sign of Heat STRESS, Leafs cant
cool enough
EDIT: Before I lowered the canopy and my AMBIENT temps reached 79 and above, my leaf temps
would run + 2F to ambient, so it helped me to recognize an issue
EDIT EDIT Also its good to take an average of Canopy Leaf Temps since it can be different depending on the
spot, even on the same BLADE
My approach is to IDENTIFY, UNDERSTAND and ELIMINATE (if possible) as many VARIABLES as I can
get enough of them pointed in the right direction and things start to get easier
thebigearl
Well-Known Member
Short of buying a small air cond. I'm stuck with what it is.
It's usually in the 40s however we've had a very wet summer this year.
Its actually been in the low 50s since I posted here so it's getting better!
Asking questions is how we find answers. It's a good thing.
Just don't take anyone's, including my answers as a gospel truth and seek out your own answers. Growing plants has been a thing for a very very long time.
Before the modern day, you'd think we hoo-mans were using stone tools until the 20th century if you read all the fertilizer companies propaganda.
Farming has been a aural tradition for 1000s of years.
Someone decided to start writing things down. The answers are out there for the folks that seek truth.
There's actual science out there too.
Just so we don't all get hung up on the VPD thing. I know it's important, but I've just harvested dried and trimmed a few plants grown in 32-35C and 60-95%RH for the entire flower cycle.
My yields were 1.3 g/watt - didn't really change much on the yield thing.
I do have some experience so I knew to keep A LOT of air moving and exchanging in the flower room as well as taking preventative measures for mold/pm.
Southern Ag - Garden Friendly Fungicide - its an organic bacteria that eats mold and the spores.
I had no mold and no PM and my plants were happy most of the time.
So like I mentioned, use those charts as a guide and don't get crazy if you exceed the sweet spot every now and again. It's not going to be the end of your grow.
I'm sure the hot summer sun at noon time temps far exceed 35C at the leaf surface outdoors. The plants will change the angle of the leaves so they don't absorb the full amount of radiation. Just another function of leaves.
Edit - here's my flowers in 35C temps and +70% RH
My yields were 1.3 g/watt - didn't really change much on the yield thing.
I do have some experience so I knew to keep A LOT of air moving and exchanging in the flower room as well as taking preventative measures for mold/pm.
Southern Ag - Garden Friendly Fungicide - its an organic bacteria that eats mold and the spores.
I had no mold and no PM and my plants were happy most of the time.
So like I mentioned, use those charts as a guide and don't get crazy if you exceed the sweet spot every now and again. It's not going to be the end of your grow.
I'm sure the hot summer sun at noon time temps far exceed 35C at the leaf surface outdoors. The plants will change the angle of the leaves so they don't absorb the full amount of radiation. Just another function of leaves.
Edit - here's my flowers in 35C temps and +70% RH
Gazoo
Member
Well said, i also see it as making it as easy on them as I can
keep in mind, I am just a small bit OCD 
OCD lol that's my initials. I just pretend I don't know there are plants in the flower room @ 35C. They do drink A LOT of water when its hot. Gallons a day per plant.
- Thread starter
- #31
Dinger
Well-Known Member
In regards to "Southern Ag - Garden Friendly Fungicide". Is this something that can be sprayed weekly up to harvest.Just so we don't all get hung up on the VPD thing. I know it's important, but I've just harvested dried and trimmed a few plants grown in 32-35C and 60-95%RH for the entire flower cycle.
My yields were 1.3 g/watt - didn't really change much on the yield thing.
I do have some experience so I knew to keep A LOT of air moving and exchanging in the flower room as well as taking preventative measures for mold/pm.
Southern Ag - Garden Friendly Fungicide - its an organic bacteria that eats mold and the spores.
I had no mold and no PM and my plants were happy most of the time.
So like I mentioned, use those charts as a guide and don't get crazy if you exceed the sweet spot every now and again. It's not going to be the end of your grow.
I'm sure the hot summer sun at noon time temps far exceed 35C at the leaf surface outdoors. The plants will change the angle of the leaves so they don't absorb the full amount of radiation. Just another function of leaves.
Edit - here's my flowers in 35C temps and +70% RH
Only need it a few times. But you can spray I think 1 day before harvest. Gotta read the label in that.
I foliared it on 2x this summer on flowering and VEG plants. I haven't seen any PM or bud rot (knock Woody).
I have 2 plants I just harvested hanging. Everything else I ran this summer was mold and PM free.
I foliared it on 2x this summer on flowering and VEG plants. I haven't seen any PM or bud rot (knock Woody).
I have 2 plants I just harvested hanging. Everything else I ran this summer was mold and PM free.
