Brassavola seedling leaves got blackish lines along midrib

[sweta]

Originally Posted by estación seca

Juvenile scale forms crawl to other plants. If you have scale on many plants you must treat all of them.

I'm not sure if other orchids also have scale. I havent notice yet but if juveniles can travel Im guessing its probably on the neighboring orchids. Most of my orchids have just started to recover after previous 2 applications of acephate. I just hope they dont go through setback. Also replacing media is going to cost me quite a bit because I already replaced about 20 orchids with new orchiata bark media after I treated them with systemic insecticide. Is there anything I can do so I can reuse the media?

[estación seca]

The ones treated with acephate probably don't have scale.

[Roberta]

Reusing media is a really, really bad idea - then you risk spreading what one plant had into the other ones. But if you recently repotted, you likely don't need to do it again... the soaking process should kill whatever may be lurking, and the imidacloprid granules will take care of any survivors.

[sweta]

Yes I agree reusing media is a bad idea and even Im against it. I didnt mean mixing up the media and using it for some other orchids but I'm just talking about sterilizing the same media the orchids were potted in. Anyways I just soaked the media in hot boiling water with some dish soap I know this will likely cause bark to degrade faster but its ok I will have to replace media sooner than usual. I think that should kill any insects if there are eggs that survive the imidacloprid granules should take care of rest.

[Roberta]

The freezer also works to kill bugs. And that might be even better than boiling - and won't degrade the medium. Sure, you can put the plant back into the same bark after you have treated it to kill whatever might have been living there.

[sweta]

Wow never thought of the idea of freezing media. How long should we freeze to kill bugs?

---------- Post added at 04:13 PM ---------- Previous post was at 04:08 PM ----------

@Roberta @estación one more question due to soaking orchids in soap water most likely water must be gone inside the leaf and psedobulb joins which could cause rot. Is there anything i can do to save these orchids from rot?

[Roberta]

If they dry out after the soaking, they will be fine. Just keep them a bit warm. (Cold+wet is more likely to lead to rot, warm+wet for a short time is fine)

I'd lust leave the medium in the freezer overnight. Then warm it up before you put plants in it (you don't want to freeze their little toes...)

[sweta]

Originally Posted by Roberta

If they dry out after the soaking, they will be fine. Just keep them a bit warm. (Cold+wet is more likely to lead to rot, warm+wet for a short time is fine)

I'd lust leave the medium in the freezer overnight. Then warm it up before you put plants in it (you don't want to freeze their little toes...)

Sounds good thanks for the advice!

[estación seca]

If there are very many insects making holes in the leaf, too much soak water can enter and damage the plant. I don't think your plant is that badly infested, but there might indeed be some damage from this.

I would reiterate that giving the plant more warmth will help a lot.

[sweta]

Originally Posted by estación seca

If there are very many insects making holes in the leaf, too much soak water can enter and damage the plant. I don't think your plant is that badly infested, but there might indeed be some damage from this.

I would reiterate that giving the plant more warmth will help a lot.

@Roberta @Estación brassavola seedling is not doing well after the water soak. Color of leaves has changed and it looks similar to erwinia fungal infection. Is there anyway I can save the seedling? I'm attaching pictures. Seems to be spreading rapidly.