Oncidium discoloration

[Nicolasdperez]

Two days ago I sprayed all my plants with a neem solution I have used before with no issue (This time I use half dosage). I am now noticing some discoloration on my oncidium leaves; I have placed it much closer to the window since last time I sprayed it. Is this sunburn? I know the sprays can increase sun sensitivity. Thank you for your time

[estación seca]

It looks like tissue damage from some reason. I don't know whether neem harms Oncidium leaves.

Oncs often have many spots on the leaves, especially in a home rather than a greenhouse.

[Nicolasdperez]

Originally Posted by estación seca

It looks like tissue damage from some reason. I don't know whether neem harms Oncidium leaves.

Oncs often have many spots on the leaves, especially in a home rather than a greenhouse.

Ok thank you. Will this continue to spread and comprise the the health of the plant or does it normally show up in some areas?

---------- Post added at 08:51 AM ---------- Previous post was at 08:45 AM ----------

Originally Posted by Ray

Neem oil is an oil. When applied to a plant that has been warmed by the sun, or is exposed to warming after treatment, oils can cause tissue damage and bud/spike loss.

Generally speaking, I think it’s best to treat early in the morning, before such warming has occurred to avoid that, and when using non-oil treatments, it takes longer for the water to evaporate, giving the plant more time to absorb the chemical.

Thank you for your help again. I applied the solution purposely during the night in an attempt to avoid this issue. I have even sprayed another oncidium (which is right next to this one) and it shows no sign of damage. Looking closely, it seems as if the leaves on the damaged one are much more shiny for some reason. I know neem is biodegradable but should I just gently wash it off to avoid further damage?

---------- Post added at 08:55 AM ---------- Previous post was at 08:51 AM ----------

Originally Posted by SouthPark

Nicolas - also check on air-movement as well. Sometimes - if there's not much air movement around the plant - leaves, stem, roots, media etc --- then some unwanted conditions can arise - like certain sorts of fungus growth.

Thank you for all your help. I think my air movement is fine. All of my orchids are in my room and I sleep with the air on and with an air filter in my room. Although, this oncidium has been a tad bit overwatered so I suppose airflow to roots could be comprised. Could that contribute to this issue? I have had one leaf yellow but the damage looks completely different.

[SouthPark]

Originally Posted by Nicolasdperez

Is this sunburn? I know the sprays can increase sun sensitivity.

If the solution is oily ----- then it might be possible for a leaf to over-heat in some regions of it ------ depending on how much energy the leaf is absorbing in various parts of it. If any parts of the leaf can't get rid of the heat fast enough, then the high temperature in the leaf (or localised regions of it) will lead to break-down issues.

I know that orchid growers recommending spraying of treatments in cool conditions ------ and not in hot and sunny conditions. Now ----- as for how long an oily layer might stay on a leaf --- this is what I don't know.

There is this youtube video here, where somebody applied neem oil solution to a phal. But she said she applied it to the roots too ------ which is probably one of those cases where they don't ask around to find out whether it's ok or not before going ahead with it ------ about applying to roots that is. I don't think it was a good idea (on her part) to apply it to roots.

That link is :

https://www.youtube.com/watch?v=lsONKFmWgHI

Her orchid in that video is still surviving, which is good. But can see some setbacks or issues that she reports.

[Ray]

Neem oil is an oil. When applied to a plant that has been warmed by the sun, or is exposed to warming after treatment, oils can cause tissue damage and bud/spike loss.

Generally speaking, I think it’s best to treat early in the morning, before such warming has occurred to avoid that, and when using non-oil treatments, it takes longer for the water to evaporate, giving the plant more time to absorb the chemical.

[SouthPark]

Nicolas - also check on air-movement as well. Sometimes - if there's not much air movement around the plant - leaves, stem, roots, media etc --- then some unwanted conditions can arise - like certain sorts of fungus growth.