Sudden death of Aerangis

[Lars Kurth]

Hi,

I was wondering whether anybody can help me. I have, or rather had a big specimen Aerangis distincta that is mounted, with 3 shoots the smaller ones with about 4 leaves, the large one had 9. 4 flower stalks.

3 weeks ago suddenly the flower buds shrivelled, then the plant started shedding all its leaves, but one (getting yellow from the growing point), then the roots are drying from the growing point. At first the disease started slow, then accelerated (most of the effects visible in the picture started 3 days ago). I have had this happen once before with another Aerangis that I bought earlier in the summer. Although that happened two years ago.

By the looks of it, I have to write off the plant. Not quite sure what this may be: could be Fusarium, which is odd as I always treat the greenhouse with Cleary's and Agri Foss such that I don't get problems with diseases in the winter.

Any advice would be highly appreciated

Regards
Lars

[Lars Kurth]

Riddle solved: black rot of the stem probably caused by decomposing spaghnum on the mount (between epiweb and wood)

[Eyebabe]

I was wondering if it could be black rot(bacterial erwinia/pseudomonas) or brown rot(fungal pythium) both of which move pretty quickly.

Fusarium progresses much more slowly. Did you consider cutting a rhysome or similar part of this plant to look for a red ring?
I have done that and one time did find it to diagnose fusarium...

But since you already know it's not fusarium, there would be no red ring

[Lars Kurth]

I was wondering if it could be black rot(bacterial erwinia/pseudomonas) or brown rot(fungal pythium) both of which move pretty quickly

Yes, I did cut the plant and there was no ring. I cut through the central rosette to see what the tissue was like and it was totally mushy, a brownish/blackish colour, all along. Probably Pythium or Phytophthora. Definitely not Fusarium.