Phal gigantea brown spots

[Theodoreorchidking]

Is this something to be worried about? On older leaves bur new ones seem to slowly develop it. Large plant

 

[RHS]

Since it‘s a valuable plant, I would first spray with a systemic broad band fungicide, and after a few days with copper.

I saw similar on a small Phal. gigantea of mine a few years ago, and it stopped after that treatment.

In may opionion it‘s a good idea to keep a close eye at Phal. gigantea in general since it is slow growing and too sad if something happens.

 

[Theodoreorchidking]

Since it‘s a valuable plant, I woud first spray with an systemic broad band fungicide, and afer a few days with copper.

I saw similar on a smal Phal. gigantea of mine a few years ago, and ist stopped aft that treatment.

In may opionion it‘s a good idea to keep a close eye at Phal. gigantea in general since its slow growing and too sad if something happens.

Thanks so much

 

[RHS]

Sorry for the many typos, I used my iPad and was too fast.

Btw. it‘s prone for crown root, but I think you know that.

 

[KenAvant1]

I grow a decent number of Phal. gigantea…hard to tell from pics…have you sprayed for spider mites ?

 

[IvoPhal]

From my humble experience, I ptopose you to treat with some systematic insecticide, acetampirid for exmple and of course you can lift gently the plant to inspect the roots.

 

[Theodoreorchidking]

Since it‘s a valuable plant, I would first spray with a systemic broad band fungicide, and after a few days with copper.

I saw similar on a small Phal. gigantea of mine a few years ago, and it stopped after that treatment.

In may opionion it‘s a good idea to keep a close eye at Phal. gigantea in general since it is slow growing and too sad if something happens.

I did the fungus but not copper. The fungus didn't do anything. How do you tell for spider mites because don't they usually have a web

 

[big923cattleya]

You have two kinds of mites. Spider mites and False Spider mites. You do not always see their webbing.
That last image you showed displays what I have always believed it to be, mite damage. You can see it easily in my opinion. So many clones of gigantea have a certain amount of a gray-green shading to the leaves, but in that last image, the area of that large leaf right next to your red shirt is noticeably gray or silvery in color. It is a bit dull, but it looks to me to be a silver discoloration, That is mite damage in my mind.
But you really need to be careful with gigantea I feel because of its slow growth habit and it seems to react negatively more often then other Phalaenopsis to sprays and chemical exposure.
Instead I would suggest wiping down the surfaces of the leaves, top and bottom, thoroughly with alcohol at least once a week for a month or so and see if the newest tissue doesn't improve.
Good luck

 

[Ray]

I agree; mites, which are affected by neither insecticides nor fungicides.

From a cost perspective, the first thing I’d try would be OrganiShield (formerly sold as SucraShield). It is not a toxin, but a “super surfactant” that is a contact killer by stripping the protective coatings off insects and mites; adults, juveniles, and eggs. They then suffocate and/or desiccate to death, and the effect is quick, usually within a couple of hours.