Worst black rot ever!

[orchidaddict789]

In the past, occasionally I had a new growth rot off here and there, and the only plants I lost were due to not reacting quickly enough. Three weeks ago, it killed one of my catt seedlings. I was upset, but not as much, because I could easily get another seedling...

Last week, I noticed with horror that one of my catts had a completely black bulb, and I quickly took out scissors and began cutting off the rhizome. I made about three cuts until the rhizome came out clean (i.e., white instead of brown), and then I made an extra cut just in case. And yes, I do sterilize my scissors between each cut, using bleach and Lysol. In total, I lost 2 bulbs and 1 new growth attached to one of the bulbs. I used rubbing alcohol and cinnamon on the cut, and I used a Q-tip to wipe the rest of the plant with fungicide.

I placed it in front of not just a fan, but a fan that uses UV to disinfect the air.

Yesterday, I thought everything looked OK, until I looked closer...and the brown has spread to the rhizome connecting the next two bulbs (just the rhizome, not the bulbs). The 3rd bulb even had rot starting from the top of the bulb and progressing downward. It seems like the rot was able to "jump" and start from a fresh new location? Cut cut cut ...and I barely have half of my plant left.

This is the most stubborn rot I've ever experienced. It seems like I've exhausted all possible solutions short of autoclaving the plant.

Anyone else had issues like this, and were able to save the plant?

[ARodney]

Shanara had a bad case of rot about two months ago which I think she still has a few plants still recovering. I don't know how to post the thread but look through the older post and you will find it. As for the rot, have you isolated the plant, cause if you didn't, it will jump to another plant. Also, what type of fungicide are you using. Besides cinammon, do you have captan? Do you have a systemic? I don't know the chemical names for the fungicides but have you tried them.

Sometimes what I do is remove the entire plant from the pot and mix, cut off the rot and spray with the fungicide. Everytime I'm gonna water, I water with a little fungicide in the water. I also don't repot, I let the plant sit in a clean pot with no medium. I know it puts the plan in stress but I don't give any ground for the fungus or rot to grow.

Hope this helps, Adelia

[orchids4me]

Shann did her thread is called "I'm starting to freak out". She had professional spayers come after sending tissue samples from 3 plants to figure out what exactly needed to treat this. She lost a a huge chunk of her collection to this and she's still at the tails battling it last I heard she still had some struggling in recovery. But it was a daily new plants popping up with it through her collection
It was horrifying at how quickly it was hitting her collection .
Make sure you isolate or toss them to protect yours while your ahead.

[orchidaddict789]

Thanks all, I checked out Shannara's thread. Oh my goodness, I can feel for her. I really hope hope everything's OK now!

As for me, in a matter of hours, the rot on the catt had spread to the next 3 pbulbs. More cutting...I'm barely left with anything. I can't believe how fast it spread! I removed the plant from its pot and medium and it was laying it bareroot right by a fan. Yet still, the rot spread. I wonder if the fungus is actually "inside" the tissue, so no matter how much I spray the plant with fungicide, the fungus is unaffected?

I've been using Daconil. It's the strongest fungicide I have in my home and it's worked in the past...I've also been experimenting with rubbing alcohol and bleach on the plant. I can't believe black rot can be so cruel!

And I just discovered that my cymbidiella that's a few ft away from the infected catt came down with black rot too. It was at the base of the new growth, and after cutting out the entire new growth, I noticed some of it has spread into the parent pbulb. Once that bulb's infected, the whole plant's done for.

[orchidaddict789]

My other question is...do you think it's because I have too many orchids? I wonder if a room can only hold up to a certain # of orchids before rot starts wreaking havoc...

My orchids aren't packed together so closely that there's no breathing space. Now I'm nervous just checking my orchids, in fear of what I would find.

[orchids4me]

Just for good culture practice it helps to have some room between the pots so the air flow can circulate through them. It help keep some issues at bay.
How do you water with a water can ? Hose? Or at the sink ? Splash can spread this also but in shanns case out side even with Fans it spread once it got in there. She had a lot of rain during the beginning of this so vry damp and florida humid so the fans to hlpe move more air even though were out side.
You need to really inspect your whole collction. Wash your hands between. Or get some antibaterial wipes use between each pot inspection is something I recommend try and stop any further spreading. You may want to get some disposable razor blades if your going to keep cutting at them also no matter how you sterilize those sissors I'd be afrais to keep them around ... You never know... For sterilizing mine I have a small torch I use.

[Shannara]

Hey Guys,

Sorry I haven't been on the board much lately and almost missed this thread. Sometimes life can get a little crazy and keep me from my hobbies.

As to the main issue here about the black rot...wow, yeah it's scary thing. I am having periodic calls with a gentleman I was introduced to via the AOS. He recommended I get a specific fungicide to paste onto any cuts of the orchids where I remove the rot. If you want to PM me I can tell you where to buy it. It is no longer available from what I can tell and there was only one source I found and they only have 5 cans left. I am going to place another order with them and get at least 1 more can. If you want to call and talk to them they seemed to be very very nice on the phone. You can purchase the product on their website too.

The only fungicide I found that is systemic to treat phytophthora, and you can buy without a license, is Alude made by Cleary. I am having a REALLY hard time getting the wholesaler to get the product in so I can buy it. I just talked to the Cleary rep again yesterday asking her if there is anything she can do to move the process along so I can get this here to spray my quarantine plants. If I can't get it soon I might have to consider paying for another spray of Heritage and Subdue. I would try looking up Cleary's website and finding their rep page and call the person assigned to your part of the country. If you have any problems PM me and I can talk to my rep about getting a gallon container for you also. They said they were ordering an entire case of 1 gallon containers...but it is taking an eternity and I am losing plants while we wait. It costs somewhere between 60-70 bucks for the jug but you only need a couple teaspoons per gallon so it will last forever.

One thing I would recommend you get immediately is get Mancozeb (it's even available on amazon). I use it whenever I water my sick plants. I want to avoid spreading anything if possible whenever water is exposed to the plants since that is how this nasty water mold travels. If you are concerned about your collection having widespread contamination I would consider spraying a systemic fungicide like Hertiage, Subdue, or Alude on the plants that could have been exposed. It can be hard to find someone licensed to spray these restricted fungicides but if you have any local garden centers who have their outdoor or tropical plants sprayed they might know someone you can call.

I am still having black rot crop up in my isolated group. So far half are showing signs of the nightmare. In the past two weeks I pulled a total of 3 plants that looked funny. The rate of sick plants is definately slowed way down in the past weeks...knock on wood. I have already tossed at least a dozen plants because they reached a point where cutting would not save the plant. The total number isolated, sick, or dead is around 3 dozen. I still feel sick in the gut about it but there is nothing I can do but what I have been doing. Luckily the weather has changed and frequent rains are no longer a major issue for me.

I would do as the others have suggested. Check EVERY plant. Gently pull back any of the brown bracts (there like the sheath for new growth) and check the area between the p-bulb and the rhizome. Isolate anything that looks funny and watch for at least a month. It can take awhile for it to show signs. I took a torch to any scissors I used for cuts and then switched to X-acto blades and tossed them after every cut because I was getting really paranoid. I would burn or seal in a ziplock bag any infected growth you cut off. Get a 100 pack of disposable gloves if you can too. Your going to need to build up an arsonal of gear and products to manage this.

Keep fans going on your plants as much as possible. I ran a huge power cord outside and run the fans often, especially after rain or watering, if it rains I hose them down with Mancozeb afterwards.

This is one of the toughest things you will go through with your plants. Try your best not to let it overwhelm you. Believe you me this has brought me to tears more than once but I have to kick myself and keep going. I hope you can get a handle on it soon. Feel free to PM me if you need to vent or need any additional information or help.

Good luck,
Shann~

[orchidaddict789]

Hmm my plants have been close enough to each other that their leaves/bulbs are touching. I am going to spread them out now.

I water with a watering can. I hold each plant over a bucket and pour water through each pot, and then I throw the water outside. Ah, I think the rain could be an issue. It rained everyday for three weeks straight in September, but since the start of Oct, it's been a bit drier.

I cut off a chunk of the Cymbidiella's last remaining bulb and dusted it with cinnamon. Now I have two small pieces of the original infected catt. *sigh* I wiped all surfaces as well as the windowsill. I inspected all plants in that problematic area and so far, so good.

And I'll go digging in the garage to see if I have any disposable blades...

[orchidaddict789]

Thank you Shann for the reply! I was typing my previous response before my internet disconnected. Anyways, that is really great fungicide info--very interesting, I'm not too familiar with any fungicides other than the run-of-the-mill types--and the Mancozab, never heard of that. Thanks for the info! I think I really need to step up my arsenal of fungicides.

Been working on my grow area until 1am, and phew, nothing so far. I also checked my nearby orchids. There were a few times when I had a few bad shocks because of a reddish tinge on a pbulb or a brown bract that looks like a brown pbulb...okay, maybe it's just too late in the night.

Oh no, three dozen plants. I totally feel for you. Every plant is like a child to me and seeing just two of my plants suffer is pretty devastating (especially if it's a plant you really like!). I guess I just haven't grown orchids long enough to experience all the ups and downs. I'm glad to hear the rate of rot has subsided, and I hope everything goes better now!

And I found one blade that's pretty rusty. Probably should go buy a new one...anyways, off to sleep...

[katrina]

Originally Posted by orchidaddict789

Ah, I think the rain could be an issue. It rained everyday for three weeks straight in September, but since the start of Oct, it's been a bit drier.

If your plants are inside...rain outside has zero impact on those plants.

There is no rule per se for number of plants a room can hold but I think it's best if they aren't crammed together super close. Air flow between the plants is beneficial. With that said...I'm pretty crowded....see pic below. This was taken last year...crowded but I have good air flow between the plants. I also have 2 ceiling fans that run 24/7 and various other smaller fans that fill in where the air flow from the ceiling fans don't quite reach.

Given that outside weather isn't an impact here, I would say look at your culture. Even plants too close don't get rot...unless other factors are at play. I would look at the watering.

[jerrymeola]

I hear the term black rot used a lot and then hear fungus spreading thought he rhizome.

These actually indicate two very different fungi.

Black rot is Pythion fungus often starting as a black spot on the leaves spreading into the rhizome.

Fusarium fungus starts in the rhizome and spreads up. It often turns the rhizome brown rather than black.

Pythion is a fungi that grows. Fusarium acts by stopping the capillary action of the plant so that the leaves and pseudobulbs never get water.

Pythion is easy to stop by cutting a leaf before it gets into the pseudobulb. Fusarium you need to cut the rhizome. Neither fungus can be 'cured'. The best you can do is stop the spread. Fusarium is much harder to stop as fungal cysts can be throughout the pot and can even hibernate for years before starting again.

It is very rare to stop fusarium once it is active. Cutting is the only solution but from my experience I do not even try any more. I rarely save a plant then it takes years to recover to where it grows well again. I would try it on only the rarest and most valuable plants. The original post describes a common infestation of fusarium with typical results.

The really bad bad news is fusarium grows everywhere in the world and is common in grass and peat moss. The best care is strong plants that can resist the infestation. Overall good care all the time.

They both spread easy so isolate isolate isolate.

[orchidaddict789]

Katrina, thanks for sharing the pic. Nice setup. I see, I have a fan but I don't think it can reach all the nooks and crannies in the house. I was just wondering about the rain raising the indoor humidity.

Jerry, thanks for the info. The first few pbulbs turned black so I thought it was black rot, and then the rhizome started turning brownish/shriveled...or even shriveled without much of a color change. Ohh I've heard of fusarium wilt--maybe that's what happened to some veggies I planted outdoors this spring. So pythium and pytophthora are similar fungi?

I guess the cymbidiella had black rot. I could pull the whole growth out and the bottom half the leaves were black. Hurray, now I have two different fungi, the more the merrier (not).

[Filb]

Originally Posted by orchidaddict789

So pythium and pytophthora are similar fungi?

Yes they are both categorized as "water molds" and are not actually classified as fungi.
Most of the species in both of those genera are nasty, nasty pathogens.

[orchidaddict789]

Originally Posted by Filb

Yes they are both categorized as "water molds" and are not actually classified as fungi.
Most of the species in both of those genera are nasty, nasty pathogens.

Ah interesting. I always thought they were fungi. I just did some quick research on water molds in general and found they are classified as protists because unlike fungi they do not have chitin cell walls and are diploid instead of haploid.

And pytophthora caused the Great Potato Famine. Talk about nasty.

[wgowen]

Have a Calanthe vestita, actually several from a parent plant, that contracted rot from who knows where, and which nearly did them in. As a last resort immersed the (leafless) bulbs in a bucket of water with about a quarter cup of bleach, let them soak for a few seconds, dried them out and repotted. These are terrestrials so dirt on the bottom, bark on top. Worked well and the senior plant is just about to bloom without going dormant first.

[Leafmite]

I had this and did the cutting but kept swabbing the 'non-infected' bulbs and leaves with alcohol, twice a day, put the plant by a heating vent in a warm, dry room (it was February), and didn't water for a week after it dried. Saved the cattleya and it recovered. (Recently, I gave it away as it was still closer to blooming than the other former seedling sibling.) I started this by getting a little water in a new growth and...wow! Nasty. I hope you eliminate it. Good luck,
leafmite

[RebelCowgirl]

Oh this post had me very afraid of rot now

[Leafmite]

Katrina, beautiful setup! And a cute guard kitty, too!
Leafmite

[katrina]

Originally Posted by Leafmite

Katrina, beautiful setup! And a cute guard kitty, too!
Leafmite

Thanks! As for the guard kitty...he's just waiting for an opp to sneak in and eat one. Orchid muncher! He likes to eat leaf tips and/or flowers. He can be very destructive so it's a good thing he is so cute.

[RebelCowgirl]

Originally Posted by katrina

Thanks! As for the guard kitty...he's just waiting for an opp to sneak in and eat one. Orchid muncher! He likes to eat leaf tips and/or flowers. He can be very destructive so it's a good thing he is so cute.

My cat does the same thing so now I keep him away from all of my orchids. I had an Ivy sitting on the end table and he completly distroyed it