Bad winter: Bacterial Issue?

[Lars Kurth]

This is the second item in the "Bad winter issue series". I am hoping that maybe somebody can help me identify what it is.

I have had a terrible winter in my greenhouse. I was not around much (travelling 3 weeks out of the month for work) for nearly 5 months now and having other people looking after the greenhouse. I often only had a day in between trips and just enough time to wash clothes.

As a consequence I now have a mixture of diseases as well as maybe cultural issues.

This disease seems to ONLY affect soft tissued and leafed plants, such as Gongora & friends, new growth of Stanhopea, new growth of Dendrochilum, new growth of soft Coelogyne (e.g. Coelogyne payishii), Ornithocephalus. It is VERY fast.

The disease always starts from the tip of leaves on new shoots, which become yellow on the leaf tip. The yellow moves rapidly down the vains, and the tissue dries behind. Sometimes you can see a slight blue sheen on the dried tissue. When the yellow has wandered to the pseudobulb, it becomes yellow, then brown and mushy. When you prick the skin liquid goo comes out. It does not smell. The speed of the disease implies something bacterial. Cutting off the affected leaves before a pseudobulb is affected seems to save the plant (or at least slow the disease), but it can come back. Sometimes watery blisters on leaves.

This has been the biggest issue for me while I was away, as it moves so fast. I had no indication of any issues when I left for a 2 week trip in January: when I got back, many plants were mush.

See attached pictures of early stages, which I have taken over time.