What’s causing the black spots?

[vipvegas]

Growing Grape Pie outdoors. Overnight two branches look like something caustic splash on them. One bud is completely bud rot and the leaves are black. The black looks like you painted it on but it’s in the leaf. Is this overwatering? This is the only plant of my 5 outdoors that was in a mix with less perlite.

 

[Gmix]

The only thing I can figure that comes close to that is leaf Septoria.

It’s not overwatering.

 

[Gmix]

I’d remove the affected leaves and rotten buds btw if it is leaf Septoria/some kind of mold or not

You could of got unlucky and some animal took a wizz on it however I’ve not seen anything like it and searching didn’t help much.
Hopefully the others will chime in soon after thier morning peace pipe
Good luck bud

 

[vipvegas]

Thanks for the response GMix. I’m a pretty experience grower with about 30 years growing. I’ve never seen anything like this.

 

[Cannaburg]

Ooooo ooooo oool I know I know.... it's the blue juice from a plane toilet!!!!!


Sorry I couldn't help it but that is a weird one and got me stumped too

 

[Deadstill]

I would really like to get that under my microscope and find out.

What are your environmental conditions like right now? Cool and humid? It could be some sort of fungi or mold.

It could even be bird shit for all I can tell.

Does it scrape off or is it embedded in the leaf?

Definitely remove affected areas, at the very least. With gloves, preferably. And don't touch any other parts of the plants after doing so.

 

[vipvegas]

Does not scrape off this is in the leaf. I’m wondering we have issues with Caterpillars in these parts of socal. I’ve had them eat the interior of the bud and cause rot but never the black. It’s interesting to say the least. I have a maple tree close with a hair hangover and thought it may be sap, but there is no weird feeling or sticky it feels like rubbing a normal leaf. If you look closer the black turns into full necrosis. I have a scope I’ll try to hit it tomorrow once the sun is up after I get off. Didn’t get a chance to but will get the affected area outta there.

Enviro has been pretty warm past week hitting 99. Usually around the 85-90 humidity this last week shot up we usually sit around 45-50 out doors got up to 68% humidity for about 3 days before this. I’m in outskirts LA area.