Brand new catasetums arrived with black spots on pseudobulbs... help!
 

I received this Catasetum expansum, along with many other orchids, from Ecuagenera on Monday, Feb 28th (so I've not yet had them a week) . This and the other Catasetum had leaves, (so assuming it's not dormant) and were shipped with moist spagh, so once I got them in their vanda boxes I watered them. I noticed these black spots so I spayed it with a fungicidal. (No other plants had the black spots). During this past week, both catesetums have lost al their leaves, which I'm sure is due to the colder weather here, and maybe a little shock, but one also formed the beginning of a new pseudo bulb today. I am not sure if I should cut off this large pseudobulbs with the black spots so the rest of the plant doesn't get it? I guess I am worried that could be too much, since I'm sure it travelled for quite a while. Any advice would be appreciated..thank you.

How cool are you keeping them?

Is the black spot firm or soft? If soft, I would cut it and treat the cut end with cinnamon.

I would also probably unpot them and let them sit bare-root to dry out. I wouldn't water again until new roots were at least 3" / 7.5cm long.

Thank you for your response. The window thermometer (south facing) currently says 70F and 56% humidity.(and 12:00 am) The black spot is hard, and i have not watered them since Monday when the arrived. Also, their roots were very long and plump, so I am confused as to if it is dormant or not. I will definately take I out if the basket and cut off the pseudobulbs as you recommend. Better to be safe than sorry.

Before you start cutting, contact the vendor with the pics. See what they say. Once you cut, you have no recourse.

Is it the pseudobulb or the papery sheath that is black? If it's the sheath then carefully remove it.

If the spot is hard...don't remove the pbulb. Recent imports can be a bit tricky and could take time to establish...needlessly removing the newest growth could result in the death of the plant.

If the leaves have dropped, treat them as dormant. The growth appears big and strong enough...it will sprout new growth when it's ready.

BTW - I would never recommend recent imports as the intro to a new group of orchids. The process is tough on most orchids and they can be tricky to get established. Always better to start out with plants that haven't endured the import process and once familiar and comfortable growing the group...then explore imports.

This is most critical with plants that show strong seasonality like Catasetum. You have a plant cruising along in Ecuador thinking that fall is right around the corner that suddenly gets put someplace where spring is just around the corner.

Remember, Ecuador is right on the equator (which runs right through Quito) so if it lost it leaves, treat as dormant - and it could be a year, without water, before it puts out new growth and figures out what season it is in a place that does have strong seasonality. I wouldn't worry about the black spot if firm, You can pot it up in dry mix, but then just ignore it until it does something.

Thank you all for your input. All the other orchids I received (13 total) are doing wonderfully and this Catasetum is hanging in there. Orchids are such little warriors! Just gonna let her rest and not cut the pseudobulb off unless it gets worse. Right now, she looks much better than she did.