White spots in hybrid cattleya - Orchid Board

Merita · #1 10-20-2019, 11:21 AM

Hello everyone:
I need advice with this cattleya. More than a month ago I had a leaf of the plant full of these spots, I cleaned it with alcohol and did a transplant because I already needed it. The spots are spreading to all the leaves, I thought they were insects but I'm not sure anymore. I would appreciate a help to identify what is happening, and what I can apply. Thanks in advance for your advice.

SouthPark · #2 10-20-2019, 04:07 PM

Was/is this orchid growing next to other orchids? And how long roughly have you been growing this orchid for? Growing media history ----- no recent repotting or recent weather activity such as lots of rain etc?

If not done so yet, then maybe just isolate the plant for now - and spray the whole plant (all leaves - both sides) ----- a very good heavy spray everywhere with natra soap. Leaves, stems, and all. Then give some good air-circulation. And then monitor the situation with the plant out of reach of direct sunlight.

Are there any markings on the other side of the leaf too?

Merita · #3 10-20-2019, 05:32 PM

Yes, it is close to other orchids, but it does not touch any, what do you think this is? I feel nervous, where can I buy Natra soap? Thanks and tell me please

---------- Post added at 04:32 PM ---------- Previous post was at 04:05 PM ----------

Sorry, I didn't answer all the questions because I got nervous. I bought this orchid in March from Hawaii, she bloomed in July and I already noticed a leaf of the plant like that, I put insecticide when it finished flowering because I had thrips insects in all. In September I did the transplant because it no longer fit in her pot and these days I noticed that all the leaves are getting like this, she achieved two new rapid growths and is getting new roots, what the plant has, I had never seen it I haven't found it online. That's it. Please explain to me what it can be, I already separated it but I have many cattleyas and I want to know the risk I am running. Thanks, I await your response.

SouthPark · #4 10-20-2019, 06:46 PM

At the moment, it's hard to say what the cause is.

As it is the only one affected while being among a bunch of other orchids or cattleya, then just simple monitoring of the situation on other plants will be ok.

Natra soap is what we have here in Australia. It's just a plant safe soap solution for handling insects on plants. In usa, they'll have similar soaps - eg. garden safe insecticidal soap, natria etc.

Some people also just use their own soap solution ----- making sure that the particular sort of soap used doesn't contain too much salts or whatever can harm orchids. So a known plant-safe soap solution is best if there's not enough knowledge about a particular soap.

Also ----- is the damage on upper side of the leaf only? Or also occurring on the under side?

It could be insect related. It could also be bacteria related too, or even fungal related.

While monitoring the situation - and if the spotting continues, then bactericide and fungicide treatments might need to be considered.

Do the leaves of this orchid get wet sometimes? Any recent heavy rain activity etc?

Roberta · #5 10-20-2019, 07:13 PM

In the US, I think Safer's Insecticidal Soap is similar the the Natra soap in Australia. The former is just a potassium-based soap (where generic soaps are based on sodium which is bad for plants) A caution using Safer's Soap... if you have hard water, use distilled water to dilute it if you get the concentrate... the calcium in hard water makes a white gunky precipitate (replacing the potassium, basic chemistry) Merita, I think you live in New York, that's not likely to be a problem, water is very pure. However, plain old dishwashing liquid detergent is fine, too - a few drops in a quart is all that is needed to "drown" insects. But whether that will do any good depends on what is causing the problem.

The first thing I think of when I see those small "nicks" in the surface of the leaf is bush snails... they are too small (like maybe 1/8 to 1/4 inch including shell) to take bites out of the leaves, but can scrape off the cuticle. However, if the problem got worse after repotting into new bark (just about the only thing that can get rid of bush snails) something else may be gong on.

Merita · #6 10-20-2019, 07:58 PM

Thank you, I always thought of an insect, but it would be too large an insect to leave those marks, in two days as it happened on the first leaf of the plant, after I saw that this was dispersing to the other leaves, I thought of bacteria because with A magnifying glass can be seen that they are a little sunken even if they are white, the older ones take on a darker color. This is only at the top of the leaves of the plant, on the underside, there is nothing at the moment. That insecticide does not exist here, natria can be purchased online. The little plant looks like I have chicken pox, I'm going to apply another soap solution in the meantime. My plants grow outside and what has hit me the most lately has been thrips. Greetings and once again, thanks for your help.

---------- Post added at 06:58 PM ---------- Previous post was at 06:35 PM ----------

Thanks Roberta, I don't know what to think anymore, I've never seen this, it's like insects scrape the leaves. Would Murphy soap serve until I go for the Safer? because in Home Depot, which is the closest I have, there isn't now. I forgot, I live in Florida, a horrible hard water. Water the plants with distilled water or reverse osmosis water. Greetings and I will keep you informed.

Roberta · #7 10-20-2019, 08:09 PM

Quote:

Originally Posted by Merita

Thanks Roberta, I don't know what to think anymore, I've never seen this, it's like insects scrape the leaves. Would Murphy soap serve until I go for the Safer? because in Home Depot, which is the closest I have, there isn't now. I forgot, I live in Florida, a horrible hard water. Water the plants with distilled water or reverse osmosis water. Greetings and I will keep you informed.

I'm not familiar with Murphy's soap. If it has sodium, not good. Diswashing liquid would be better. If you do get Safer's Soap, definitely use distilled or RO water to dilute the concentrate. But if the leaves look "scraped" that sure sounds like what bush snails do. And when you repotted, they could have "hitchhiked" if they were hidden among the roots. If you water the plant well (like water running through it, maybe even add a little dish soap) , in a little while look at the edge of the pot or basket. If you see a tiny shell that looks a little like a flying saucer (sometimes the "resident" will even stick its head out, not much bigger than a hair) then you'll know. They hide in the medium and among roots... come out mostly at night. But if the plant gets a good batch, it may inspire them to show themselves. (I know an elderly orchid hobbyist who claims that there are two kinds of people, those with bush snails and those that need new glasses... They are tiny and shy but destructive, they also nibble on roots)

rbarata · #8 10-21-2019, 04:30 AM

Some people put a piece of lettuce on top of the medium.

Ray · #9 10-21-2019, 09:16 AM

Murphy's would be fine, as it's mostly based on plant extracts. I sometimes use Dawn as a wetting agent. No problem with it, either.

Merita · #10 10-21-2019, 12:52 PM

Quote:

Originally Posted by Ray

Murphy's would be fine, as it's mostly based on plant extracts. I sometimes use Dawn as a wetting agent. No problem with it, either.

Hi Ray, I'm glad to see you, I have read that you say you always have Orthene and I wanted to ask you a question. I can use the one they are selling in the stores for fire ants (50% acephate) or buy the granulate by Amazon Orthene 97, the thrips are ending with me, I have sprayed several times and they are not leaving, they are destroying me all the flowering . This year has been horrible, ants, thrips, mites and the ones I don't see.