Fusarium oxysporum on Catasetum

[Lars Kurth]

Hi,

I just have lost a nice Catasetum which I bough this spring at the RHS orchid show. The plant was imported from South America and grew on really well. Suddenly over a period of 3-4 weeks it deterioted very quickly. I didn't notice earlier and when I saw the plant this morning, I knew that this was probably the end of it. Maybe some parts could be saved through major surgery.

I thought I'd share some of the pictures. It may help somebody in the future. I am pretty sure the plant had Fusarium oxysporum - probably already when I bought it - and the onset of winter triggered a rapid demise or secondary infection with Erwinia.

It looks as if the disease spread from the rhizome to pseudobulb 3 (the latest growth and thus the most suscteptible and from there to the older bulbs 2 & 1).

The two tips of the older pseudobulbs were still firm and had no colouring,so it may still be possible to save a bit of the plant. But it is unlikely.

In any case: I was surprised about the speed of the demise and the lack of any warning signs. It just shows that one has to be extra careful with imported plants at this time of the year.

I don't think that I overwatered: if anything I kept my Catasinae too dry. I stopped watering nearly a month ago after the plant flowered for a second time this year.

Regards
Lars