The Charts--Helpful charts for making nutrient deficiency diagnoses

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seaslug

seaslug

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VPD explained in an OSU Extension Fact Sheet: http://ohioline.osu.edu/aex-fact/0804.html

I feel like being a troll this morning so I'll say I don't buy it. I'm vegging in a Seattle basement and have 42RH with 70F below plant level. I'm not going to add moisture to get out of the Red Zone and it's raining right now.

2nd edit: I guess the VPD really applies in a greenhouse or tent.
 
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ftwendy

ftwendy

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I think about VPD as a measure of vacuum pressure. It is a measure of how hard the air is pulling water through my plants. Higher temps with lower RH have a stronger pull, whereas lower temps with higher RH have a weaker pull. The most useful aspect for me is the ability to control the same VPD/Vac force at different temperatures and RH.

Example: when everything is perfect, I keep my veg at 65%rh at 80f...... a target VPD of 1.22..... Now let's say it is a cold week and I'm having trouble maintaining a warm veg space, and for whatever reasons the warmest I can get it is 64f... In order to match the VPD conditions at 65%/80f (1.22) at a lower temperature, I need to lower my RH to 40%.

I also use VPD a lot when I'm drying and curing.
 
ftwendy

ftwendy

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I feel like being a troll this morning so I'll say I don't buy it. I'm vegging in a Seattle basement and have 42RH with 70F below plant level. I'm not going to add moisture to get out of the Red Zone and it's raining right now.

You're fine..... all told, 42%/70f (1.5vpd) isn't that far off of what's acceptable - however, the key to this chart is its use in maximizing speed of growth. At 70f your plants aren't working very hard. Otoh, if you were running at 80f, then VPD would become more important b/c the plants metabolism would be cranking closer to capacity. It's most helpful for me at the high and low ends of the acceptable range of temps and rh... like when the power goes out or something strange like that
 
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Seamaiden

Seamaiden

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Hotay, today I'm adding some pix of a boron (B) deficiency, from @IPlay4Keepz -- which were not properly diagnosed until much later. Thread here: https://www.thcfarmer.com/community/threads/take-a-look-at-my-dying-white-master-kush.55023/
so you can follow the progression of observed problems and how he finally made a diagnosis.

And the pix of the plant.


Boron deficiency1
Boron deficiency2
Boron deficiency3
Boron deficiency4
 
caregiverken

caregiverken

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Hi Sea, I hope you dont mind me posting this here..I dont mind deleting or moving it

This just showed up on just 2 leafs
the rest of the leaves and the other plants are perfect so it stood out alot
Leafspots

Im not really worried yet..unless it spreads...Im just wondering if it looks familiar to any one
 
Bigphotoofleaves
caregiverken

caregiverken

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Looks like insect damage Ken...
Thanks FTW
I better spray em then....
I have been just spraying Caps on all the small plants and they are loving it
I always get mites...and it looked like the caps forliar was keeping them away..

But I moved these plants into a tent recently and may have skipped their caps:banghead:
Fucking tents are mite heaven :mad:

I have a brand new bottle of Safer brand 3in1 Ive been saving for a while
I also have a 5gal jug(lifetime suppy) of Stylet oil
 
caregiverken

caregiverken

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Don't forget that you can mist isopropyl inside that tent and if you do it every three days for two weeks, you should have them eradicated, with zero residue (especially if you use distilled water to cut the iso).
Thanks Sea...I do forget about iso..But I have used it before...Great tip!
 
caregiverken

caregiverken

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Looks like insect damage Ken...
I know spider mites make lots of small spots on the leaves...what make big spots like these?
But I dont see well, untill I post a macro shot...lol
I think im seeing the spidermite damage now:banghead:

Nevermind...delete my posts..I was oftopic anyway:bag:
 
M

Mr_Marley_Jim

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Hi Seamaiden,

I don't mean to clog your thread, but does this look like the boron deficiency you posted about previously? I can't figure this thing out, it seems to only be affecting this strain.
 
IMG 6440
Shamus

Shamus

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mg causes mottling like that as well ime on the beginning stages of it at least, could be wrong, is there bite marks on the bottom that looks like its been eaten? if its generally smooth like the rest of the leaf id say mg,
just a throwin it out there
 
Seamaiden

Seamaiden

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Hi Seamaiden,

I don't mean to clog your thread, but does this look like the boron deficiency you posted about previously? I can't figure this thing out, it seems to only be affecting this strain.
I can't make out what you're trying to show. The plants look alright to me, though a bit P-.
 
Amber

Amber

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Thanks FTW
I better spray em then....
I have been just spraying Caps on all the small plants and they are loving it
I always get mites...and it looked like the caps forliar was keeping them away..

But I moved these plants into a tent recently and may have skipped their caps:banghead:
Fucking tents are mite heaven :mad:

I have a brand new bottle of Safer brand 3in1 Ive been saving for a while
I also have a 5gal jug(lifetime suppy) of Stylet oil
Keep changing it up mites adapt well.
 
caregiverken

caregiverken

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Keep changing it up mites adapt well.
Thanks another good tip..
I sprayed em with 50% ISO alcohol /water (a couple times now) and then, stuck them outside..
No mites in the GH right now thankfully..probably too cold at nite :)
 
lone420ranger

lone420ranger

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That's the best damn chart I have ever seen regarding plant defiencies.

Seamaiden, I can't thank you enough for posting this up.
 

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