Yellow orange spots on phalaenopsis leaves

[chantrelle]

I have 3 hybrid phalaenopsis that have some yellow orange spots on their leaves.

It’s mainly on the leaves exposed to light (top leaves). I grow my phalaenopsis under T5 Fluorescents.

Here are some pictures

Phal II Spot by chantrell99, on Flickr

It is on the side of the leaf as it exposed to the light.
Phal
II side spot by chantrell99, on Flickr

The plant its self looks rather in a good shape.
Phal II by cha
ntrell99, on Flickr

Here it’s starting on another one

Phal I Spot by chantrell99, on Flickr

Would that be a virus, a fungus or due to the light ?

[Ray]

While I cannot say what the discoloration is, I can say that it is not wise to let water droplets stand on the leaves like that. You should water the potting medium, not the plant itself.

[chantrelle]

Originally Posted by Ray

While I cannot say what the discoloration is, I can say that it is not wise to let water droplets stand on the leaves like that. You should water the potting medium, not the plant itself.

Oh thank you ! I never knew if that was true or not. I will be now carefull with this.

[Ray]

Water droplets are perfect incubation grounds for molds and bacteria...

[Keithj]

Water droplets can also act as lenses, focusing sunlight onto the leaf surface.

Keith

[Ray]

I've heard that, but it seems to me that if the focused light generated enough heat to cause any leaf damage, it would be sufficient to evaporate the water, making that self-correcting.