Any Ideas?? - Orchid Board

Cavs n' Orchids · #1 12-27-2011, 05:26 PM

I have had this Catt for 5 years or so, and I was wondering if anyone knows why some pseudobulbs get this burnt look. It isnt squishy, and it has happened before without hurting the plant, just making it unsightly. It kinda has a burnt look, but I am pretty sure its not sunburn because they leaves have always been fine, its just the pbulbs that are affected. I only fertilize VERY weakly once or twice a month and the roots never get that burned look. Maybe fungal, but I spray 4 times a year with Physan. Anyone ever experience it or have any ideas?
Btw, this guy is C. Hawaii (C. Rembrandt x C. bertii)

Merlyn · #2 12-27-2011, 05:33 PM

I think it just turns that color as it gets old and used up. If it did that on a pbulb with a leaf, I'd worry. My mentor has a HUGE greenhouse with 3000+ orchids, most of which are Catts. When we repot them those burnt looking and leafless backbulbs get broken off and discarded.

tucker85 · #3 12-27-2011, 05:41 PM

The psuedobulb is dying. It may or may not be due to a fugus. When that happens to my cattleyas I cut the psuedobulb off, as close to the base as possible without damaging the rhyzome. If you have any fungicide it would be a good idea to treat the plant. My plants seldom suffer any ill effects from something like that but on rare occasions it can turn out to be an aggressive fungus that will spread to the rest of the plant. Good luck.

Cavs n' Orchids · #4 12-27-2011, 05:47 PM

Thank you for your quick and very helpful responses! I will take your advice and get rid of the offending pb's since they are older ones and physan the cuts. Hopefully it isnt anything that will spread to the new ones!

Ray · #5 12-28-2011, 08:40 AM

1) Don't remove them until they have become like dry husks. The plant is removing stored nutrients from them. If they are soft and mushy, that's a whle different story.

2) Do not apply Physan to a cut. It accomplishes nothing, except possibly poisoning the plant. Physan is a topical disinfectant, and a fresh cut will be pathogen-free, assuming you used a sterile cutter as you should always do. It will not be a very good preventive.

If you just let it dry, it will be fine. If you want to force it to be dry and apply a mild preventive at the same time, dust the wound lightly with cinnamon powder.