Vanda Cell collapse???

[Hennie Steyn]

Hi everyone,
within days about 50 of my Vandas attracted a disease, cell collapse or whatever!!! Can anyone help?

[RedEcho]

To hot or cold? It looks a little like sunburn but not quite. I lost some orchids to freeze, this year, they looked similar.

[Hennie Steyn]

Nope, temp range between 23 - 40c under 50% shade plus plastic!

[Kmac]

It looks like some kind of fungal or bacterial rot, but that really doesn't help much. You might find this article helpful: http://www.houstonorchidsociety.org/...ySueBottom.pdf

What an awful thing to have happen...hope that you can stop whatever this is.

[orchidsal]

I know this doesn't help much, but I am so sorry this has happened..........I wish I knew how to help you, but I have never encountered this kind of "cell collapse" before. Good luck and I hope someone can seriously help you stop this progression in its tracks! AL

[opaline]

I know this doesn't help much, but I am so sorry this has happened..........I wish I knew how to help you, but I have never encountered this kind of "cell collapse" before. Good luck and I hope someone can seriously help you stop this progression in its tracks! AL

Very sorry to read of your misfortune and bad luck here at this time, i can with confidence measure the great extent of the devastation and disappointment clouding your world at the moment. Bacterial/ fungal infections spread extremely quickly after entering the plant through varying channels. If it were one plant it could be a infection that has entered through a wound but for all your plants in this quantity it could possibly be.

1 'Drift' from nearby usage of chemicals causing tissue damage - phytotoxicity and secondary bact/fung infection.

2 Contaminated water source?

3 cold water prolonged contact and filtered sun exposure.

I can see from your pics that these are plausible due to signs and symptoms. Cell tissue collapse, fungal and bacterial.

You will need to take measures too isolate and treat with strict hygienic practices - the slightest drop of water from infected will contaminate new easily.

[opaline]

To help whilst you are clouded by what has happened, will be a bit clearer. Easy to discount possible culprits.

Drift - gardeners/ contacters spraying poisons/ weedkiller. The chemical? mixed in with water as molecules can travel uncertain distances on a windy/ breezy day. Likely if your incident is sudden.

Water/ storage contamination - Last summer my friends kid amused itself by throwing offcuts of railway sleepers into rainwater butt or tried to anyway. After i screamed and gave him some money to stop crying i could not take the chance with plants as lethal/ toxic (now banned) chemicals and poisons were used to treat sleepers.

Any idea on the period of time this commenced till now? Primary bacterial/ fungal infection causes plant parts to smell bad, go brown and mushy however very common as a secondary ailment.

[zainal abidin]

OMG so sorry to hear that to me look like bacterial or fungi infection I personally will cut the affected leaves but you said " within days" I agree with Matt could be somebody sabotage your water source.Logically if infection it will take at least few days to a week go and investigate to rectify the problem if not due to infections.

[tucker85]

I'm no expert but have you changed anything about watering or light? It looks more like a physical or culture damage rather than a disease. I notice it doesn't have a lot of roots for a vanda that size. When a vanda with a small number of roots is exoposed to too much sun or placed in a less humid environment it can get burnt. If nothing has changed about the culture then I would suspect some kind of contamination of the water source. Good luck. I hope you find the problem.

[opaline]

- cool and damp (spraying too late in day near a temperature drop) . All those crowns and bracts perfect for collecting water which is lethal. Pathogens will enter through epidermal cell damage from rot.

Extracted from gardener article - info and awareness.
Pseudomonas Cattleyae
Pseudomonas cattleyae, also known as 'brown wet spot' occurs mostly in phalaenopsis. However, a similar wet bacteria infection can occur on other orchids as well.

Plants develop brownish black, soft areas usually starting on the underside of the leaves and quickly penetrating to the leaf surface. This affliction is a destructive rot which can spread with amazing speed, taking in the entire plant within only a few days. The cause is a combination of cool temperatures, high humidity and inadequate air movement. Prevention is easier than the cure. Keep minimum night temperatures around phalaenopsis at least 60 to 65 degrees F along with brisk air circulation. Brown wet spot can not develop under such conditions.

Remedy: If the disease has reached the crown portion of the plant, there is no cure even if some of the leaves look healthy. On phalaenopsis, if caught early, the affected portion of the leaf should be cut off (well below the afflicted area) with a new razorblade or some other sterilized cutting tool. Wet rot on other orchids must be treated by lancing and then cutting and/or scraping out the damaged tissue.

Dust the cut surface with sulfur or a good powdered fungicide. Lacking these, you can use regular mouthwash, applied half strength. Try to rapidly dry off the injury by placing the plant before a fan. Isolate from your regular growing area to prevent any spread of the disease.