Dendrobium Royal chip with black spots on leaves

[marla468]

I am fairly new at caring for orchids and my beloved Dendrobium is not doing well. Please let me know if the spots are something I should worry about, should I spray with fungicide? Which one is best for this type of problem? Do I need to remove infected leaves? If so I might have to cut them all! Some new growth looks promising! Thank you all for your help.

[dbarron]

Don't do anything drastic until you know what you're dealing with (that includes spraying anything or cutting anything).
I am not at all certain, but I lean toward sunburn and possibly mechanical injury. It also looks like the canes are wrinkled, which would indicate it's gone through some dehydration.

[Dimples]

I don't grow those, but what have your temperatures been like? How much light does it get?

[dbarron]

Whoops...got stuck by replying to wrong message (ignore this one)..can't find a way to delete it

[estación seca]

I agree not to cut off anything. I see a lot of scrapes and scratches, which are of no concern. But the leaf with dark banding makes me wonder whether you have spider mites. They readily attack thin-leafed orchids. Do a little reading here on spider mites.

[marla468]

Thank you for the replies! My dendrobium is outdoors, I am in South Florida where it is very hot and it has rained very little this summer. It is usually under an oak tree, I have moved it to isolate it from my other orchids, it now has a bit more sun exposure.

Will not do anything to it for now besides cleaning it with soapy water and see if anybody has a clue of what else it could be. Thanks again!

[Roberta]

The last photo looks like a bit of sunburn. (It may get darker with time... sun damage can develop slowly) The dry leaf tip would be consistent with dehydration. There does look like some mechanical damage - bumps and scrapes. Bush snails can do that too... they are too little to take actual bites, they can scrape tissue from the surface of leaves. For now, I think reduce sun somewhat, water more frequently. Unless you have spider mites (which can be controlled with soapy water if applied every 5 days or so for several weeks) I don't see anything that would spread to other plants. The damaged leaves won't "heal" but won't hurt anything either. Don't cut - I don't see anything fungal. You'll get clean new growth in the spring.

The second photo also shows medium that looks a bit old. When was it last repotted? If it has been more than 2 years, I'd also suggest repotting in the spring when you get new growth. (But not until then) At that point, if you rinse the roots well before repotting, you'll also take care of any bush snail issues that might be there. (Bad roots due to broken down medium can also cause dehydration)

[marla468]

Thank you Roberta! Yes I was going to change pots now, will wait until spring!

[estación seca]

There are lots of fungal issues growing outdoors in Florida. I suggest joining a nearby orchid society.

[Ben_in_North_FLA]

All great advice above on this latouria den. I would not be so concerned about foliage but more so on media as it seems kinda worn and soft. The black leaf tip may be calcium deficiency. As you grow this outdoors I would suggest switching to a net pot and using coarse media to allow roots to dry tween waterings. I have recently bought a few latouria dens and they love the net pots. Will post a few more details with pics in the morning