Phal experts..HELP!

[Stone]

One of my amabilis has been doing really nicely on a cork mount. Suddenly it has developed some kind of disease the starts at the beginning of the root (near the leaves) and collapses the root quickly progressing downwards toward the root tip. The tip remains green and healthy for a while then the whole thing is dead! (they are not soft and slimy but more hard and leathery) Some roots are still not affected. Most are. What the hell is going on?????????
I keep them warm, 20-27C and water whenever they are dry (which is every day)
I also have an Oncidium lanceanum with (I think) the same problem. Only on this one it starts as a purple discolouration just behind the tip for a few days before the root collapses.

 

[abax]

Stone, have you got new root tips starting? I have many
mounted Phals. and a lot of the old roots die off as new
roots begin. I've noticed this cycle for many years. Usually
I just cut the old roots off after they've completely dried.
I don't have many hybrids, so I'm referring to species and primaries. Can you post a photo? Are you using a bit of sphagnum on the
mounts? Perhaps the mounts should have some new sphag.

 

[naoki]

Did you use some chemicals recently or spill coffee on it? It's unlikely that this is the cause, but I sprayed with 2% caffeine (to control bush snails), and saw the similar symptoms. Caffeine is a phytotoxin which stops root growths, and roots growth stopped immediately as expected. But I trusted a scientific paper which proposed Caffeine as the snail control, which said they didn't see much phytotoxicity in Orhicds. Catt, Dens, Paphs, Phrags had the retarded growth (immediate stops of growing root tips), but Phals were severely affected by it (and I lost quite a lot of Phal species). Others started to regrow after a couple onths. But the Phals which died had the roots killed in the similar way, and the roots became dry, leathery.

 

[Ozpaph]

do you have a photo?

 

[paphioboy]

Are the roots yellow-light brown and shrivelled?

 

[naoki]

Mike, here is the caffeine damage of a survivor: Phalaenopsis schilleriana. Is your problem something similar? Most of the brown roots used to be healthy before the application. The root death occurred over 2-3 weeks period after application of 2% caffeine (I did apply Metaldehyde and Physan 20 around the same time, but they are unlikely to be the cause). After 1-2 months, the new roots started to appear, so this one will be ok. If you look at the root next to the label, the root death is still progressing (from the base of root toward the tip). It's as if the plant is "aborting" the roots.

 

[Stone]

Mike, here is the caffeine damage of a survivor: Phalaenopsis schilleriana. Is your problem something similar? Most of the brown roots used to be healthy before the application. The root death occurred over 2-3 weeks period after application of 2% caffeine (I did apply Metaldehyde and Physan 20 around the same time, but they are unlikely to be the cause). After 1-2 months, the new roots started to appear, so this one will be ok. If you look at the root next to the label, the root death is still progressing (from the base of root toward the tip). It's as if the plant is "aborting" the roots.

Yes they look similar to that naoki but no caffeine involved. The roots don't change colour they just start to rib and collapse almost as if they are deciccated. As I said though, some (2) roots look ok still. I suspect some kind of pathogen like pythium or something. I soaked the whole plant in Banrot and sprayed all the others too. I'll get a pic of it soon.

 

[paphioboy]

Maybe Fusarium infection. If your plant has a long enough stem and enough healthy roots, I suggest cutting the non-infected portion (top-cut) to remove it away from the rotten base. Then pot separately and discard the portion with rotten roots. I have done this with several phals, both the large-flowered and novelty type.

 

[Kostas]

I have never sprayed pure caffeine but I do spray coffee from both used and new coffee grounds on my cycads and orchids, including species Phalaenopsis, get sprayed too preventively for any(usually non existent thankfully) bug problems. I have never seen an adverse reaction to it by any of the plants, only a nice deeper green coloration very soon afterwards, from minerals contained in the coffee


As to the mount in question, check if it's normal senescence or pathogen related. Root die back can happen normally for a number of reasons but the way it does it sounds more pathogen related, like the stem is rotting for some reason. Maybe it rests on continually moist sphagnum? That wouldn't be very good. Otherwise a stem rot generally isn't too easy to happen on a mounted plant

 

[naoki]

I have never sprayed pure caffeine but I do spray coffee from both used and new coffee grounds on my cycads and orchids, including species Phalaenopsis, get sprayed too preventively for any(usually non existent thankfully) bug problems. I have never seen an adverse reaction to it by any of the plants, only a nice deeper green coloration very soon afterwards, from minerals contained in the coffee

Kostas, I think you are probably safe although I don't know the exact sensitivity of orchids to caffeine! Brewed coffee has 400-800 mg/l (ppm) of caffeine, which is 25-50x less than what I used. And if you are using spent coffee ground etc, caffeine concentration is even lower. But I'm not so sure about the merit (over more conventional fertilizers) from my reading.

 

[Kostas]

I see, way less caffeine. It's enough to knock down mealy bugs and scale for a good many months off my cycads. I actually found used grounds to be more effective than new, I stand coffee grounds but it may be than I used less of the fresh out of fear for phytotoxicity.
I don't use them as fertilizer on the orchids, just as a spray when I do the cycads as there are a few orchids growing among them such as Neomoorea and in the past, P. gigantea(this one is indoors some years now). The dark green cast is just a plus I have noticed

 

[NYEric]

Naoki, the roots in the media are dying - hint.

 

[Stone]

Ok so here's the amabilis below. You can see that the problem starts at the plant and moves down.




And here is a seedling of Cattleya aclandiae:



Thinking back to what I may have done to both of these I remembered having sprayed them with copper oxychloride a couple of weeks ago (and other plants too) It could be chloride poisoning??
A disaster! but some where not affected

 

[gonewild]

When I saw the wire my first thought was what metal is the wire...copper? Then you said you applied copper spray. Your problem is copper toxicity. Excess copper damages plant roots.

 

[Ozpaph]

I seem to remember that dendrobes (?hardcanes) dont like copper oxy. maybe the phals are the same.???

http://staugorchidsociety.org/PDF/FungicidesandBactericidesforOrchidDiseases.pdf

 

[naoki]

What concentration did you use, Mike? In the top Phal, did the roots which are touching the black webby materials died more? Maybe they had a longer contact time. In my case, the mounted plants didn't have enough time to get toxins, and most damages are plants in pots.

I haven't used much copper products other than Phyton 27, but this shows that the phytotoxicity depends on the pH and it can damage roots:
http://www.nzjf.org/free_issues/NZJF08_2_1960/33FE2C4C-E0A5-4254-8184-7545A905ED41.pdf

Here is a related info (which I thought informative):
http://cvp.cce.cornell.edu/submission.php?id=140

 

[Stone]

naoki;553852]

What concentration did you use, Mike? In the top Phal, did the roots which are touching the black webby materials died more?

I probably used about 1gm in a litre. It didn't make any difference whether the roots were touching the fire or not.
So copper? I guess it could be but I wouldn't have expected such a quick response from copper at a more or less neutral pH. The leaves are comletely unaffected. Either way I won't be using that again! I have soaked the affected plants in Calcium hydroxide in the hope that it halts or slows down the damage. Hope they recover :sob:

 

[DeafOrchidLover]

I used ginger for snail control which I had on phalaenopsis species speciso and it works well. ground ginger, I just sprinkle light on its potting media.

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