Fungus - BL Ports of Paradise

[Clawhammer]

I found some yellow spots on the front of 2 of my Blc Ports of Paradise's older leaves. Turned them over and there were little white spots on the underside where the yellowing was. Other leaves do not have either yellowing on top or little white spots on the bottom.

I am guessing fungus and thinking a systematic like daconil. Let me know your thoughts and any experience with this. Should I treat all catts in my collection?

Thanks everyone.

[Roberta]

Little white spots on the underside of the leaves where you see chlorotic areas on top? Scale would be my guess. Your pesticide of choice... and then go back in a week and do it again. And the week after that again, with something else (so you don't create resistance) The bane of Cattleyas.

[Clawhammer]

Originally Posted by Roberta

Little white spots on the underside of the leaves where you see chlorotic areas on top? Scale would be my guess. Your pesticide of choice... and then go back in a week and do it again. And the week after that again, with something else (so you don't create resistance) The bane of Cattleyas.

Thanks Roberta, exactly. I have been looking at the plant for about 30 minutes with my magnifying glass for about and can't find anything. I have had scale on a couple other plants, but never this kind of chlorotic spotting. Do some plants have a worse reaction to scale bites than others?

I'll alternate Bayer 3-in-1 and Azamax as you suggest.

[Roberta]

Originally Posted by Clawhammer

I have had scale on a couple other plants, but never this kind of chlorotic spotting. Do some plants have a worse reaction to scale bites than others?

I'll alternate Bayer 3-in-1 and Azamax as you suggest.

I see it from time to time on other plants too (like Oncidinae and Vandas, etc.) but Catts are prime offenders. I don't think the little nasties are particular. They hide under the leaf, and suck the juices from below so they can be at it for quite awhile before it appears on the top of the leaves.

[Clawhammer]

Scale confirmed, thanks Roberta. Better than a fungus or a virus I guess

Would you treat the other catts too if you were me? I try to limit the use of these kind of chemicals because I grow inside. Anything indoor friendly-ish? Thanks and for steering me down the right road.

[Roberta]

Originally Posted by Clawhammer

Scale confirmed, thanks Roberta. Better than a fungus or a virus I guess

Would you treat the other catts too if you were me? I try to limit the use of these kind of chemicals because I grow inside. Anything indoor friendly-ish? Thanks and for steering me down the right road.

You can just keep an eye on things... But if you wanted to treat with Bayer's or other systemic, might head off the spreading. Anything lighter as a preventative is probably useless since likely only to kill on contact... or in the case of scale, maybe not. It's really persistent.