black rot

[palito]

So this morning I noticed that the new growth in one cattleya had stalled completely.... I touched it and it felt loose. I squeezed it and it was mushy and leaking some brown juice... so i pulled it out...

I googled and it seems to be the dreaded "black rot" disease which is supposed to be a very nasty aggressive fungus that kills cattleyas quickly.

I cut about an half an inch from the rotting point and already found green healthy tissue, i soaked the wound in fungicide.

Should I be more aggressive and cut more extensively to stop this infection? any tips are welcome.

[fred]

it sounds like you treated this realy well with the use of fungicide

as it is a new growth I was wondering if you have been watering or misting the orchid and water has run into the center of the new growth as this will also cause the growth to rot as well

[kmarch]

I think you"ve handled this well. The best treatment I know for this kind of rot is 1) don't waste time in treating it, 2) cut it all off, cutting back into healthy tissue to make sure you have it all gone, 3) treat with fungicide.

Watch it carefully for any more signs of rot. I'd reduce my watering. It would be good if the cut could dry out good and seal the incision. About 6 months ago I lost a growth on my Slc Wendy's Redstone to this kind of rot. I did what I suggested and it seems to have stopped the rot and I now have 2 healthy new growths in full swing.

Good Luck!

[Cynthia, Prescott, AZ]

You may want to try to increase you light for your problem plant and make sure all misting is done early enough in the day that there will not be any moisture on the leaves and new growths when the temp starts to fall late in the day.

[palito]

thanks all for your insight.

this plant is a basket exposed to a lot of sun and had been growing well. The problem is the unusual rain this season. It rains every day/night, it is not windy and the plants never get dry grrr.

I moved it to a place sheltered from the rain to let it dry.

[palito]

hehe. this is an update exactly one month after my original question.

The surgery worked!. the plant is now growing 4 new leaves simultaneously, but slowly. It used to grow only one leaf at a time but at a much faster rate.

Other orchids got the same nasty black rot in the growth points or in the aerial roots. but it doesn't surprise me. There is an epidemic of rot, blackspot, mildew and all sorts of fungi right now in the area with all the rain and stagnant air around.