black disease on leaves
 

I am actually quite ignorant when it comes to bananas, so I figured I should ask some knowledgeable people. I believe this is a basjoo. Below is some links which hopefully work correctly and show images of what I'm talking about. Basically a new leaf comes out fine and the banana is continuing to grow and get bigger. However, after coming out, the new leaves quickly start getting what appears to be black mildew/disease and the leaf quickly declines. It grows fast enough to keep producing new leaves, but it is weird the leaves decline this quickly I think. I'm not sure if this is a disease or some sort of cultural thing (water, sun, etc). The black stuff does not rub off, but is an internal part of the affected leaf. I have sprayed with some fungicides and things and it didn't seem to have any change. I have many other varieties of banana, but this is the only one doing this. Any help would be greatly appreciated.

Re: black disease on leaves
 

Where are you located, in the south I'm guessing?

Re: black disease on leaves
 

This picture does not look like Black Sigatoka, but what you discribe is very much like the behavior of Black Sigatoka. What Fungicides did you use? :2239:

Re: black disease on leaves
 

I should have mentioned my location. . .I'm inland southern california. . .zone 9b. . .pretty harsh sun/heat, low humidity, etc.

Re: black disease on leaves
 

This happens to some basjoos here in the south. I do not know the cause, but hot dry weather makes mine look that way too. They seem to like it less than 85f more(at least mine do).

Re: black disease on leaves
 

I actually was wondering if it is getting too much heat. I have a lot of canopy in my yard due to taller trees, but this location gets blasted pretty good middle of the day. Obviously in my part of the country it is very frequently over 85 degrees. Since basjoo is supposedly cold hardy, I have wondered if like some palm trees (such as Rhopalostylis) it also resents too much heat. I.e. it prefers an overall mild climate, not the extremes of heat and cold one finds in california desert.

Re: black disease on leaves
 

Sorry to bump my own thread, but I don't feel I really arrive at a consensus yet. Anyone else care to offer their opinion as well?

Re: black disease on leaves
 

Not real sure what that is, but after seeing a presentation on plant diseases, I would guess it's a bacteria. No, it's not "wet"...not a bacteria.....but probably something bad.
Sorry to say, I would yank it out and dispose of it.
Try contacting this man....
Robert Cating
Grad research Asst, Diseases of Orchids
Plant Pathology Dept, UF
Plantmd@ufl.edu

He gave a great talk on orchid diseases at Jackosnville Orchid Society and is very knowledgeable re: plant diseases!

Margie:waving:

Re: black disease on leaves
 

So I just noticed this (or something very very similar) happening on my Ensete Maurelii. The older leaves have areas of black streaks/areas. That plant has been nothing but problems since I've had it...they're beautiful plants, but I'm tempted to get rid of it if it doesn't just grow normally WITHOUT issues!

Any information you can offer me on such an issue would be greatly appreciated!

Re: black disease on leaves
 

My guess would be fungus. If contact fungicide did not work, try a systemic fungicide.

Re: black disease on leaves
 

it looks like some kind of an environmental stress reaction to me. The newer leaves don't look like that, right (hard to see in the picture). Cut off the leave that bother you and see if it doesn't just grow out of it. Definitely not a cause for destruction of the plant.
Also do you have spider mites?