Rusty neck

[Fredmax]

I have a problem that seems to eventually impact all my paphs and would like to better understand the cause, as shown in the pic the neck of the fans all seem to get this reddish rust marks that tends to eventually deteriorate the leaves. I've dealt with mealybugs (the white on the roots is remnants of a confidor tablet), and have seen spider mites time to time so am trying to control them, would the damage be attributed to them or is it a fungal issue that's the cause? Me and my paphs thank you.

 

[Russ1992]

I have the exact same issue with mine. I have no idea what the cause is either.

 

[Ozpaph]

First, the roots look really dry. I dont think its rot as its the leaf edges. Could be 'bug' damage. Id check you are watering enough. Better air movement. Close observation.

 

[SouthPark]

True ------ maybe more air movement in the growing area can cut down or eliminate chances of that happening. Earlier this year, I have a baby Paph. vietnamense that started getting fairly bright rust coloured patches on the leaves to begin with ---- maybe mites started things off. And then the rot started ...... was not lightning fast rot .... and not snail pace. I tried thiomyl and yates anti-rot phosacid ----- which didn't help. And finally tried copper spray ----- which stopped whatever it was in its tracks. The result was impressive. Immediate stop of all spreading activity.

I have a vietnamense growing right next door to the one that developed issues, and other plants all around it. This was the only one that got affected by whatever that was.

 

[Fredmax]

Wow that doesn't look good, impressive that it got halted.

Whatever has got my plant (lost tag but think it's P jackii) is getting momentum, the same affliction took out a few species last season - all starting with the rusty neck. Strangely every brachypetalum is unaffected. Much like last year the decline occurred right on spring when I moved them from the house to the greenhouse. I do have spider mite issues, but that's from the house.

I have restricted water over winter but the dry roots was directly after I sprayed it with Confidor ( Imidacloprid) and let it dry out before repotting, some did better after I transplanted in clay balls, the leaf loss slowed.

 

[SouthPark]

Fred - you're in Australia too, right? I bought 'liquid copper' from Bunnings. Provide some nice gentle air-movement around the plant too if at the moment it doesn't get much air flow.

True .... totally agree Fred ..... for the baby Paph --- the rot maybe took out three-quarter of one leaf ..... and once the copper spray was applied, the undamaged portion has just stayed like that --- remaining green and functioning. Also interesting that a single older leaf was untouched - and remained in pristine condition throughout the 'ordeal'.

 

[Ozpaph]

I think they are too dry. Check the underside of the dying leaf tip by wiping with a clean moist white tissue - any spider mites etc???

 

[Fredmax]

Just an update, I cut the leaf below the yellowing and am growing in on my windowsill where it can be monitored, I have been watering it vigorously in the warmer weather and the yellow has stopped. I've also used a insect bomb as was recommended to me for the mites and has worked wonderfully.

It's safe to say I've got the potting media wrong, but tried to put it in a dry media so stop further rotting. I need to do some searching on the precise media to use but am starting to think the leaf issues are a result of dehydration as it stopped the moment I watered it more regularly.

I'm also certain the red marks are mealy related as other non slipper orchids show similar neck marks and can usually find a few of them in the crevasse of the leaf, these things are a true pest! For fungicide I'm using something fairly nuclear called Octave in straight powder form, it seems to work well but have to mask up and wear gloves within 1 mtr of it, I haven't seen other fungicides have as instant effect on slippers.

 

[Ozpaph]

glad its doing better

 

[Russ1992]

Just an update, I cut the leaf below the yellowing and am growing in on my windowsill where it can be monitored, I have been watering it vigorously in the warmer weather and the yellow has stopped. I've also used a insect bomb as was recommended to me for the mites and has worked wonderfully.

It's safe to say I've got the potting media wrong, but tried to put it in a dry media so stop further rotting. I need to do some searching on the precise media to use but am starting to think the leaf issues are a result of dehydration as it stopped the moment I watered it more regularly.

I'm also certain the red marks are mealy related as other non slipper orchids show similar neck marks and can usually find a few of them in the crevasse of the leaf, these things are a true pest! For fungicide I'm using something fairly nuclear called Octave in straight powder form, it seems to work well but have to mask up and wear gloves within 1 mtr of it, I haven't seen other fungicides have as instant effect on slippers.

I have applied Copper, Thiomyl, Physan, and Hydrogen Peroxide to mine as well to no avail. I don't have the leave dieback that you experienced though. I was starting to suspect a pest issue as well but I can't find any spider mites and I don't see any Mealybugs.

 

[Guldal]

If you have a good, nice orchid nursery with an experienced owner in your vicinity, I would in your shoes ask them for advice.
If they are someone you already know, I think you could just bring one or two of the plants, when visiting. If someone you haven't encountered before, I think I would give them a telephone call, telling them, that you are planning to come by and buy a couple of plants (and of course dutifully do so, if their response is positive) and ask, whether it would be ok, if you brought a couple of examples of the ailing plants for good advice.

My mentor in all things orchiadic, Hans Christiansen of Fredensborg, with whom I over the years have developed a friendship, is never stingy with advice, when it comes to culture and/or pest control. And with his 50+ years experience as independent nursery owner, I can't fathom when some amateur growers (as in f.ex. a few members of our orchid society) think they know so much better, than a man with this vast, professional experience.
Sometimes I sense, he doesn't think all the questions, he gets from his customers are equally qualified, but - as I've mentioned before - he is working from a maxime of the higher good: The plants, "...but they are living beings!"

Kind regards,
Jens

 

[Russ1992]

This

If you have a good, nice orchid nursery with an experienced owner in your vicinity, I would in your shoes ask them for advice.
If they are someone you already know, I think you could just bring one or two of the plants, when visiting. If someone you haven't encountered before, I think I would give them a telephone call, telling them, that you are planning to come by and buy a couple of plants (and of course dutifully do so, if their response is positive) and ask, whether it would be ok, if you brought a couple of examples of the ailing plants for good advice.

My mentor in all things orchiadic, Hans Christiansen of Fredensborg, with whom I over the years have developed a friendship, is never stingy with advice, when it comes to culture and/or pest control. And with his 50+ years experience as independent nursery owner, I can't fathom when some amateur growers (as in f.ex. a few members of our orchid society) think they know so much better, than a man with this vast, professional experience.
Sometimes I sense, he doesn't think all the questions, he gets from his customers are equally qualified, but - as I've mentioned before - he is working from a maxime of the higher good: The plants, "...but they are living beings!"

Kind regards,
Jens

This is exceptional advice I really appreciate it Jens. I will be doing this for sure.

 

[Ozpaph]

looks like trauma with secondary ? fungal infection which is localised. Probably nothing to worry about.

 

[SouthPark]

I had one rust patch begin to grow in a vietnamense fairly recently ----- but this time, with the advantage of having previous knowledge about what could work ----- sprayed that part with copper solution. And it really has stopped it dead its tracks - whatever it is.

 

[cnycharles]

One note for people who have spider mites; if you apply imidacloprid, it’s like fuel on a fire for mites. The population will grow

 

[southernbelle]

One note for people who have spider mites; if you apply imidacloprid, it’s like fuel on a fire for mites. The population will grow

That is true, as imidacloprid does not kill mites of any kind. There are some combination products (Bayer) that contain it and other things that say they do, but alone it’s does not.

 

[cnycharles]

Here’s an article that suggests that imidacloprid kills some spider mite predators, which wouldn't necessarily affect mites in a home, but seems to show that fecundity of the mites increases after being exposed to imidacloprid

https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0020018
most things get unhealthy when exposed to chemicals but it seems mites get ‘happy’

 

[SouthPark]

For the spidermites ------- there's a product called azamax ------ could give that a try (if available) - although it does have a bit of a smell.

Or maybe neem oil spray with a bit of pyrethrum liquid mixed in for good measure - for spidermites that is.

 

[Ray]

I am a big fan of Azamax, even at $100 for a quart. It’s a good insecticide and miticide, and affects adults and juveniles.

 

[richgarrison]

+1 on azamax...

applied via a fogmaster or spray or drench i've done all of them

and similar issues to the ones in this thread have almost gone completely...

in a crowded northeastern us greenhouse with 700+ slippers