Phal Disease Spreading Fast: Virus, Fungus, or Bacteria?

[mbentley]

Dear Orchid Board Community,
I have a dear collection of many different types of orchids in my home, and recently, all of my Phals have started developing an unsightly yellowing (and then browning and cell collapse) in the foliage. The blight is spreading quickly. They have all succumbed within about 3-4 weeks. I have noticed one of my paphs is also displaying some yellowing, although it does not appear as dire.

I'm concerned that it is one of the dreaded viruses that plague orchids and that I will loose much of my collection. I have started preemptively treating with physan, just in case it is a fungus or bacteria. I have not done any pruning or cutting recently of any of the orchids, nor do I recall adding any new orchids to this particular table in the last few months. I'm attaching some photos representative of various stages of this ailment. I hope folks in the forum can help me identify what is killing my orchids.

Many thanks!
Merideth

[Ray]

It's really hard to diagnose such things from photos alone, but I'd guess an acidovorax (pseudomonas) infection is the likely cause. It is a water-borne bacterium, so any splashing between pants can spread it easily.

Your Physan application is a good topical treatment, but I'd recommend a copper-based treatment for the internal infections, or Inocucor Garden Solution, which is a blend of beneficial bacteria and fungi that predate pathogenic ones. (Full acknowledgement, I am the sole US online retailer of Inocucor 's product, but I only do because I believe in it, and they asked me to...)

[jkofferdahl]

This is a post where I'm glad Ray answered! Your photos are rather frightening. A bacterial infection can pretty quickly destroy a plant, and as he pointed out it can spread from simple splashing.

Like Ray, I use a copper-based fungicide/bacteriacide instead of Physan. It's systemic, meaning that it gets into the plant.

[mbentley]

Thanks to Ray and Jeff. I've ordered Inocucur, Phyton 27, and a horticultural oil (just in case it's false spider mites). Given the extent of the infection and how quickly it's spreading, I'm going to go straight to the Phyton on the phals. The paphs, oncidiums, and milts will probably get the Inocucur treatment.

I fear I've already lost a few of the phals, but I'll see how it goes.

[Ray]

DO NOT use Inocucor and Phyton or Physan together. Inocucor's living cultures will be killed by them.

[mbentley]

Gotcha. Just like probiotics and antibiotics in people!

[greenpassion]

I need to chime in here. I looked up the product that Ray has and I found the price to be inhibiting for me. Does anyone out there know of anything that is comprable but priced lower? I still have not decided weather to take my chances with this Sogo V3 comma or throw it away.

[NYCorchidman]

My thoughts.
The first photo, pseudomonas.
The third one, is it Paphiopedilum? It looks like a natural dying back.
The rest looks highly virus related.

If they are supermarket mericlone hybrids that are highly replaceable, I wouldn't go through any headache but rather start new and clean.

[mbentley]

Unfortunately, these are not supermarket specials, but a collection I have been building for about 12 years from very reputable growers. Now my tropical plants (mainly philodendrons) have also started melting. They turned brown and pretty stinky over a 5-6 day period. I've also noticed that the hostas outside my windows also have similar spotting on the foliage, as do the leaves on my neighbor's dogwood tree near the border of the property. It's been pretty rainy in my area all Spring/Summer, and I'm wondering if this isn't a fungus or bacteria that I've picked up from outside? I usually take care to keep my humidity levels around 60% and air flow high (from a ceiling fan) in my orchid room, so the environmental conditions should be fairly good.

I'm treating aggressively with Phyton 27. I'm not sure what to expect, other than to hope it will halt the spreading. I very much appreciate everyone's input on the problem. It's nice having a community to go to for advice!