Pathogen. Thats all I know.

[Dunge]

I offer for your consideration an AK48 from seed that is three weeks into 12/12 lighting.
I first noticed leaf damage back at the flip. Unfortunately it persists to this day when I decided to cut off the troubled vegetation and and try to figure out what is attacking my plants.
Visual inspection found no bugs.
Fungus?
photo 1: First noticed folded leafs with blackened center.
photo 2&3: Front and back.
photo 4: the girls. My troubled one looks good but for a few missing leaves. Lots of new growth and green.
I did a Neem oil foliar spray for lack of any better idea.
You farmers have been a great help in the past.
Any thoughts?

 

[EZnot]

Got the same thing going on with the Blueberrys - WTF!? Thought it was damage from the spider mites, but looks more like a nutrient thing to me. I could use some help, too. Thanks.

 

[Dunge]

Most of my vegetation is healthy and growing; not nutrients. And the damage is highly localized.
What is the size range on mites? Should I be able to see them under low magnification?

 

[Seamaiden]

When I can't figure it out, I move outside cannabis searches. Here are the results of my initial Google searches.

leaf folded blackened center disease

As ever, one thing leads to another...

IPM Series Pome Fruit HG 76 pfv

fire blight treatment

I have no idea if I'm on the right track, just hoping to show you how I've been able to answer a couple of tough problems using this method. Beyond this, search .edu and ag sites. Best of luck!

 

[lazarus718]

Your blackened center disease is a bit of a mystery for me...I'll have to look into that one more. I just sat down at the computer with a glass of a good Argentinian wine and a bowl of my very own Magic Schoolbus, about to put on some tunes then I'll toss on the thinking cap. Your 2nd and 3rd pics of the fan leaf indicate a LIGHT BURN to me bro, especially if localized. Especially if you left the girls unattended for a few days in flower. Just a shot in the dark on that one and it might be something obvious you already would have checked for but thought I'd mention it all the same. Let me see what I can find.

 

[lazarus718]

Alright bro, did my researching and tune listening to and took me about 5 mins to come up with "Blackspot" a.k.a. "Black Dot". If your black spots started as 2mm diameter spots on your leaves near mid vein, then you might have this fungus. It will eventually cause necrosis of the plant tissue and it will turn yellow, die and fall away. It is apparently a bi-product of a stressed plant. From what I read it is a condition that affects cannabis and is not normally found in healthy plants. If it sounds like that then let us know and I'm sure one of us farmers can help you track down the cure.

 

[lazarus718]

Sorry man, forgot to tell you how you transmit the disease between plants:
"The conditions that promote blackspot are wet leaves, splashing water and warm temperatures"

 

[Dunge]

Thanks for the input. I think you might be correct about the fungus and clearly a stress response.
At this point, my other plants seem to be resistant, so I'm just going to see if I can bring her back to health.

 

[xX Kid Twist Xx]

is the fan blowing on them they seem like they are wind burned. since they are seedlings u will see this as clones dont normally get wind burn.

 

[mellokitty]

photo 1 looks like botrytis to me. that's what the underdeveloped/bottom buds on a plant with gray mold sometimes look like.
photos 2 & 3 DO look more like windburn.
what is the troubled one's water uptake like? and has she ever been overwatered or waterlogged at any point? what's your humidity like?
the last time i saw that pattern of mold (yellow stamen with even distribution of necrotic area across leaf tendrils) was when my room got floooooded (like, "they took 3 full days longer than they normally would have before they needed water again"-flooded. good grief.) once i cut off all the gray (but not yellow!) and conditions returned to normal they all came back nicely.

 

[bluewaves]

theres such thing as wind burn? wow i learn something new everyday!!thax guys my problem solve to much direct hit from fan

 

[mellokitty]

@bluewaves: the back-and-forth action of an oscillating fan is ok (and actually welcome) but i find that the first one in the row where it pauses before rotating back sometimes gets it too.

 

[BigCountry]

What's the humidity in the room, and temps, and lighting?

 

[Dunge]

Humidity was too high (60%) and temps too low (68 deg F).
This is the sole clone that I was able to keep going from a sateva seed sprouted July '10.
This seems to be a response to stress but it looks fungal so perhaps it is a fungal bloom allowed by plant weakness.
I have it under fluorescent lights along with other mothers that I am attempting to grow and clone with no indication of communicability.
I can find growth centers that are putting out fresh unaffected vegetation, but many of the nodes seem blackened and arrested.
I am attempting to take clones from this plant but I suspect that cloning from a weakened state will be a disappointment.
Thanks for having a look.
I have attempted to post an image but it keeps failing.
Did they put a file size limit on us?

 

[Seamaiden]

Those temps and RH are not at all out of range. Assuming it is a fungal pathogen, it is my opinion that a systemic may be required. However, if it were my plant(s) then I'd be hitting them, in veg, with Kop-R-Safe, every 7-10 days until something shows one way or the other. I would also give it aspirin.
Aspirin Water Helps Plants

 

[mellokitty]

if it's starting to put out unaffected new growth i would hold off on taking clones off it until it recovers a bit more, you might just clone your problem into your new plants, and unhealthy cuttings off an unhealthy mom might simply not take; if the cutting is too busy trying to stay alive on top it won't put roots out at the bottom.

 

[Dunge]

Don't clone yet. Don't I know it.
Too late. Six cuttings later all are doing well.
Gave her a drink with an aspirin in it as advised.
Last watering was a half gallon (three gallon smart pot) with molasses, seaweed extract, and some soil fungus innocent with humic acid. The pot was full of fresh Fox Farm Ocean Forest three months ago.
Watching and waiting.
I believe the stressor was an acidic rain water bath I gave them back in January. All three of my strains took a shock but this sativa is the only one to look like it may not make it.
This is why I think what looks like a fungal attack is a stress response weather fungal or not.
I will try again to attach a photo.