Black (or is it purple?) on undersides of leaves

Hey everyone.

This plant, and the other one that are having this issue, have previously had a pretty rough go of it, but they re all still in veg, and I think I have the issues sorted. FWIW, I think I had soil borne critters and nute def(s). Switched to organic nutes, and watered with nematodes. It's only been a few days since I fed then organically with nematodes in the water/nute mix. The plants seemed a lot better immediately after that.

Anyway, I have found 2 plants that have had this black, or maybe dark purple stuff on the undersides of the leaves only, that looks almost powdery.

Generally speaking, the plants all look pretty good, except for a little residual leaf tip curl, which I am hoping will go away soon.

Other general conditions are that it has been low humidity for a veg period (max of 60%, give or take), and the day/night max/min are 86/76, but mostly it stays between 79 and 84.

If this is a problem in the making, I want to take care of it now, but I don't want to actually cause problems by fucking with the plants unnecessarily. Anybody have any thoughts?

Thanks!

u had any ph problems?

Interesting that you'd ask that. I was told that I was probably, and to invest in a good ph meter. I did, then I got stuck on the fact that I couldn't find a definite and accurate way to measure the soil ph. So, for now, the meter sits unused.

But, when I started with organic nutes (Some nice compost tea including bat guano, mixed with comfrey tea), all the problems that I was having seemed to go away, unless this one was happening, too. Maybe it was, I don't know.

More than likely a form of mold/fungus. Better address it ASAP!

^Slanty said:

More than likely a form of mold/fungus. Better address it ASAP!

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Ok, thanks. I pruned the leaves that had the issue. Any other suggestions?

Why is everything in that picture green? EvVen the wooden stool and the should be white baseboards, lol

SaneLawsMake4SaneSociety said:

Ok, thanks. I pruned the leaves that had the issue. Any other suggestions?

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yeah... what is your humidity levels? Do you have good air flow? A couple things to look into!

Mopaba said:

Why is everything in that picture green? EvVen the wooden stool and the should be white baseboards, lol

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lol, i think its that the flash went through part of the leaf

^Slanty said:

yeah... what is your humidity levels? Do you have good air flow? A couple things to look into!

Click to expand...

low humidity for a veg period (max of 60%, give or take), air flow, meaning new air coming in, old air going out, is good, and air ciculation around the room is good as well.