Two Oncidium issues: Black stripe on one, new growth dying on other

[My Green Pets]

Issue 1: The black stripe!

This stripe of blackening tissue has appeared very suddenly on this Oncidium hybrid's leaf. Is this indicating something serious? It reminds me of the symptoms a Brassia showed earlier this year...its pseudobulbs eventually rotted, one by one! Don't want this to happen again!



The rest of the plant looks fine, I think...



Issue 2: New growth dead?

This is a Sharry Baby hybrid that is putting out a new growth. Unfortunately the newest leaf has turned brown and died. Is this new growth finished? Could it have happened because water got in there and festered? Could it spread/Should I remove it?

Thank you!

[Leafmite]

I am not certain what the line in the leaf signifies but I would probably remove the leaf.
With the Sharry Baby, I would try to remove all the leaf that is brown and then pour Isopropyl alcohol into it for a few days in a row (do not get the alcohol on the roots). You will lose the leaves affected but if the pseudobulb is not yet affected, it should be okay and at least put out a new growth when it reaches maturity. It might even bloom. I have had this happen before. :|

---------- Post added at 06:22 PM ---------- Previous post was at 06:19 PM ----------

Just wondering...what is the plant behind the Brassia? It doesn't quite look like my Piper but it is just as pretty.

[tucker85]

I think both plants look pretty healthy. I wouldn't worry about the black line. It might be something that happened while the leaf was growing out. The second one has some fungus on that one new growth. Your orchids will be less likely to have fungus problems if you give them plenty of calcium. You can use a cal/mag fertilizer that contains calcium, a cal/mag supplement from hydroponics stores, or dolomite lime in the medium. If you're using distilled water or RO water, I would consider using both a cal/mag fertilizer and a cal/mag supplement once or twice a month.

[NYCorchidman]

For the first picture, virus (particularly CymMS comes to mind) or fungal. I would lean more toward the virus.

Second pic, definitely a rot starting on the new growth.
I would also cut off and do something about it as this kind of wet brown rot progresses quite fast.
I would take that entire new growth off as the older pb will easily just send up another one in no time.
Otherwise, you are risking the rot move into the pb, which is then the end of the plant, so act fast!

For your first plant, test for virus if it's valuable to you.

[judith_arquette]

I lost a bllra. Tropic Tom 'Honker' to the same black stripe thing as your pic. Eventually all the pbulbs rotted like your Brassia. I wish I had treated mine sooner and more aggressively but being pretty new to all this I was uncertain and chose the "wait and see" route...
Good luck and please keep us posted.

[My Green Pets]

Thank you guys and gals for your help! Tonight, based on your suggestions, I attacked these problems!

Issue 1: Removed plant from basket and picked all old, rotten potting material from the roots. Cut off the entire affected leaf and pseudobulb, leaving me with a small, two-bulb division. Soaked plants in insecticide/fungicide solution for 20 minutes. Repotted in lava rock.

Issue 2: With sharp pruning scissors, I snipped off the new growth as close to the bulb as I could. The cut looked clean so I sprayed with fungicide and put the plant back in its spot.

Fingers crossed that it did the trick! Moral of story: Water carefully and sparingly in winter!

[RJSquirrel]

I dont know why you chose lava rock, but many use it...

I got tired of cutting my hands up handling it and it didnt seem to help me any with my overwatering issues.

[Jenn4a]

Originally Posted by NYCorchidman

For the first picture, virus (particularly CymMS comes to mind) or fungal. I would lean more toward the virus.

I guess I wasn't the only one who thought so initially. I've been doing some "research" on illnesses and I recognize that a stripe/streak isn't a good sign.
I have no personal experience with viruses, but I'd watch for more streaks to show up on other leaves and pseudobulbs just in case. :/

[Leafmite]

Originally Posted by RJSquirrel

I dont know why you chose lava rock, but many use it...

I got tired of cutting my hands up handling it and it didnt seem to help me any with my overwatering issues.

I do agree that the red lava rock is tough on the hands. I also agree that it can hold water. What is nice, though, is that it doesn't hold more and more water as time goes on, as bark does as it decomposes. I always use basket pots with the red lava rock, as well as with my new favorite medium, LECA. I kill everything in bark and I don't like the cost of buying new potting medium and disturbing the roots every year so this sort of medium makes quite a bit of sense for me.

---------- Post added at 01:56 PM ---------- Previous post was at 01:49 PM ----------

I agree with Tucker that a little extra calcium can go a long wy with preventing the die-off of new growth. The other two suggestions are to always make certain that the orchid is planted on top of the medium so that just the roots are in it and, secondly, when watering, be careful not to get water in the new growths. I learned these three things the hard way. :|

[My Green Pets]

I am a fan of lava rock so far, just needs to be flushed well from time to time. I wear gloves when handling it

Some pics post surgery

1. The little division repotted in bark.

2. Together with the larger plant in beautiful, clean, rot-free lava rock

3. The stump of the amputated rotten growth.