Black rot on Cattleya? - Orchid Board

SJF · #1 06-01-2013, 10:26 AM

Hi,
This Cattleya (in the first four pictures) was in a four inch pot. I had to cut off the rest of the plant due to yellowing and softening of the p-bulbs. They turned dark and I cut those sections off. I sprayed what remained in the first four pictures with Physan 20. I cut if off and reported it in a much smaller pot in Orchiata. I thought I got all the diseased plant areas off. I love the flowers on this one and now what is left of it has yellowing and browning of the remaining pseudobulb. I sprayed it with Physan 20 last night. Would a systemic fungicide save it or is it a total goner now?

The last two pictures are of an orchid (different one than first pictures) that arrived from the grower with black pseudobulbs. I cut them all off and repotted it. This is what is left of that one. The leaves on one area turned yellow. This one, unlike the other, doesn't have soft pseudobulbs. Should I cut more off and treat it systemically?

Lagoon · #2 06-01-2013, 04:47 PM

It looks to be an old cane on its way out, so I'm not so sure I would be saving this piece, This how many of my catt p.bulbs have died off.

SJF · #3 06-01-2013, 04:52 PM

Quote:

Originally Posted by Lagoon

It looks to be an old cane on its way out, so I'm not so sure I would be saving this piece, This how many of my catt p.bulbs have died off.

Thanks, the first four pictures are what is left of a larger plant that was in a four inch pot. I am really sad that I won't be able to save it. I bought it in Jan or Feb and the flower was beautiful.

The other pictures are of another plant that I tried to take the bad parts out of. Another are is now yellowing.
It arrived in trouble.

Lagoon · #4 06-01-2013, 04:55 PM

Don't sweat too much, this small piece will not flower again, you're new growths will

SJF · #5 06-01-2013, 04:59 PM

Quote:

Originally Posted by Lagoon

Don't sweat too much, this small piece will not flower again, you're new growths will

Thanks, that is all that is left of this one though. The last few pictures are of a different plant. I wasn't clear in my descripton. It was clear in my head and it didn't translate to my fingers, lol

Leafmite · #6 06-01-2013, 05:50 PM

Black rot!

I went through this and lost many of my cattleyas. I saved a few with cutting and isopropyl alcohol but most were too far gone by the time I found they were infected. It cropped up in different cattleyas even weeks later! To prevent this, increase calcium and plant your cattleyas on top of the medium. I haven't had a case since. Good luck!

james mickelso · #7 06-01-2013, 05:59 PM

The last two pictures are of a plant that is just aging. Not all brown, shriveled pbulbs have rot or anything other than just old tissue. The second to the last pic is of some pbulbs with this years growth buds beginning to grow. Look at the base of the pbulbs. You'll see the new buds. They take awhile to get going but they will get going this summer. Just water it as normal and watch them grow. The first series of pics I can't see the bases. That is all that matters when pbulbs get old. Too many people throw away perfectly good plants just because they don't look like the pictures in the books. Take out the top most media in the first plant so that you can see the bases of the pbulbs. Don't keep it too wet. The new buds are growing from the starches and sugars contained in the old pbulbs because they have no roots of their own yet. Lewt nature take it's course and next year you should have those lovely flowers again. Here are some pics of nearly dead plants that have now grown new growth and are on their way to looking good again.

naoki · #8 06-01-2013, 06:59 PM

James, you are a good orchid doctor! Did you have to do something special to save the 1st and third ones? Or just keep them drier with higher air humidity and wait? Did you figure out what caused it?

james mickelso · #9 06-01-2013, 09:55 PM

I use a lot of different techniques to save or propagate the rescues. The first pic shows an orchid that I think to be about 10 years old according to what was in the pot when I unpotted it. Lots of old stumps and no roots and nothing but dirt which at one time was large bark. I kept the newest (last 3 years) growths because there were latent buds that had not shrank. I used a modified spag and bag on this. The next season the buds swelled and I got two pbulbs out of it. I sold this as part of my sale last year. The third one is a pic showing what the 5th and 6th pic was like when I started trying to get the only latent bud going. It now has two good leads and lots of roots. This has been a two year project so far. Couple more years and it should bloom. I have no idea what the name is. Most of this group came with no tags. Here was part of the group I got that I tried to rescue. I saved something from each pot. Three have flowered so far. C. General George Patton (two divisions have flowered with one flowering twice so far. C. Karen Gubler flowered last season. And an unknown C. which was white. My point was never give up on a plant until it is obviously gone. Not every problem is insurmountable. Of course this applies only to those who like the challenge and have the room.

SJF · #10 06-01-2013, 10:28 PM

Quote:

Originally Posted by james mickelso

I use a lot of different techniques to save or propagate the rescues. The first pic shows an orchid that I think to be about 10 years old according to what was in the pot when I unpotted it. Lots of old stumps and no roots and nothing but dirt which at one time was large bark. I kept the newest (last 3 years) growths because there were latent buds that had not shrank. I used a modified spag and bag on this. The next season the buds swelled and I got two pbulbs out of it. I sold this as part of my sale last year. The third one is a pic showing what the 5th and 6th pic was like when I started trying to get the only latent bud going. It now has two good leads and lots of roots. This has been a two year project so far. Couple more years and it should bloom. I have no idea what the name is. Most of this group came with no tags. Here was part of the group I got that I tried to rescue. I saved something from each pot. Three have flowered so far. C. General George Patton (two divisions have flowered with one flowering twice so far. C. Karen Gubler flowered last season. And an unknown C. which was white. My point was never give up on a plant until it is obviously gone. Not every problem is insurmountable. Of course this applies only to those who like the challenge and have the room.

You give great advice.

Have you ever had an orchid recover from black rot?