What disease will this be?

[Merita]

Today cut this pseudobulb of a cattleya, which about nine months ago began to get this color and slowly rising from the rhizome upwards. In the center it was green but the tissue that covered it was dead as you can see. The plant is in good condition and finished its flowering so I decided to cut this bulb that was in the center of it. Apply daconil in the cut, I suspect the fungus Rhizoctenia S. I would like to hear your advice.