What the heck is this?

[noochka1]

Can anyone tell me what this is, and how to be rid of it? It's attacking my spicerianum and it needs to stop!!!!! :-(

 

[Ozpaph]

looks like a chemical burn as the leaf was emerging from the axis.

 

[big923cattleya]

I am not so sure about that. If you look at a neighboring plant, up in the right hand corner at the one o’clock position, another leaf on another plant is exhibiting the same discoloration. Have you changed fertilizers, used an insecticide, sprayed alcohol or anything else recently???
The cause could still be chemical in nature but it appears to be on a few different plants.
When you look at the large spot in the center of the image, at least two other leaves have the identical discoloration on them as well. One in fact shows spots when I look at it magnified a bit!

 

[noochka1]

That's definitely a possibility. I had to use an insecticide to get rid of some thrips recently and perhaps I over-applied it. I'm annoyed that it caused the damage, but happy that this isn't a virus or something truly horrific. Thanks a lot!!!!

 

[big923cattleya]

As long as you follow mix directions and apply under appropriate conditions, you should be fine.
I have seen orchid hobbyists mix it too strong or apply at the wrong time of the day and then end up with a chemical burn.
It is like they think a tsp. Per gallon is called for but I really want to kill those stinking bugs so I’ll use a tbs. Well a tablespoon is 3 times or 300% stronger.
Good luck and you are very welcome.

 

[dmcmkl]

I'm not sure about the large area at the base of the leaf, but the other leaf spots look like a leaf spot fungus I developed on a few of my plants. It is spread by water splashing from one plant to another. I treated my plants as directed by an article I found on the St Augustine Orchid web site:

Treatment: Spray with a suitable fungicide containing copper or quaternary ammonium compounds, Daconil or Cleary's 3336, or the some of the fancier fungicides like Heritage or Pagaent, following label instructions.

I sprayed the leaves of infected plants and any nearby plants with Phyton (copper based) and and then Pagaent a couple of weeks later. Stopped the infection and I have not seen it since. Seemed fairly easy to deal with for me at least.

By the way, if it is one of the fungal leaf spot diseases the spots will never go away. They will just stop spreading.

Good luck!

 

[noochka1]

Thanks! I think I might actually have some Daconil sitting around somewhere. I've been using Physan religiously, but it doesn't seem to address some pathogens. I'll give the Daconil a shot this week and see what happens. At recommended dosage, of course

 

[big923cattleya]

Sincerely, I hope you figure out a remedy!!

 

[Ray]

Thanks! I think I might actually have some Daconil sitting around somewhere. I've been using Physan religiously, but it doesn't seem to address some pathogens. I'll give the Daconil a shot this week and see what happens. At recommended dosage, of course

Physan is a particularly effective disinfectant, but it is topical only and will not help control systemic diseases.

 

[Ross]

The "whiting out"spots on your leaves looks somewhat similar to a situation I encountered with my Paphs a few years back. To prevent the chance of bacterial infections during the dark, winter days of November and December here in northern Minnesota, I tried adding a small amount of Physan 20 to my regular waterings. A month or so into this regimen, I noticed white spots occuring. I discontinued the Physan 20 and the leaves were greening up by March. This may not be your problem, but it is something to consider.

 

[l_kikkert]

looks like a chemical burn as the leaf was emerging from the axis.

 

[noochka1]

The "whiting out"spots on your leaves looks somewhat similar to a situation I encountered with my Paphs a few years back. To prevent the chance of bacterial infections during the dark, winter days of November and December here in northern Minnesota, I tried adding a small amount of Physan 20 to my regular waterings. A month or so into this regimen, I noticed white spots occuring. I discontinued the Physan 20 and the leaves were greening up by March. This may not be your problem, but it is something to consider.

Good info. I have been using Physan religiously to avoid bacterial issues, but I'll try discontinuing it for a while and using Daconil periodically instead. Thanks!

 

[Ross]

Good info. I have been using Physan religiously to avoid bacterial issues, but I'll try discontinuing it for a while and using Daconil periodically instead. Thanks!

I still use it. Just not as often and only when I anticipate a problem.

 

[richgarrison]

Realize we are a forum of folks that fundamentally want to help, and have significantly varied experience, knowledge, and trouble shooting abilities. That said, if your issue is a phytoxic reaction to a chemical spray you applied, you probably want to consider that heavily when thinking about applying more chemicals.

In terms of diagnosing ailments, you may find that the photos, diagnostic tools, and remedies documented by Sue Bottom Here are useful. She has published articles in the American Orchid Society journals as well, and is considered knowledgeable on these topics.

Good luck

 

[noochka1]

Thanks, I appreciate that!