I have rust

[OrchidTraci]

on my paph leaves. Why is this and how do I deal with it?

[LJA]

You'll need to spray with Disease Control, Traci. At this time of year, when most of the country is hot and humid, fungal and bacterial infections can be rampant. If you don't have any fans set up in your growing area, some extra air movement will help. Also, if you do any gardening where you might come into contact with pathogens on your outdoor plants, wash your hands before handling your orchids. Unfortunately there's no way to "fix" infected leaves without cutting away the diseased portion, but you can at least keep the infections from spreading.

[OrchidTraci]

You'll need to spray with Disease Control, Traci. At this time of year, when most of the country is hot and humid, fungal and bacterial infections can be rampant. If you don't have any fans set up in your growing area, some extra air movement will help. Also, if you do any gardening where you might come into contact with pathogens on your outdoor plants, wash your hands before handling your orchids. Unfortunately there's no way to "fix" infected leaves without cutting away the diseased portion, but you can at least keep the infections from spreading.

That is so strange because I have fans running at least 16 hours a day, and humidity is the same. It has been hot though, and humidy for 3 days. I don't garden near my growing area. It is a back porch outside of the door where I have been growing them. This stinks. What should I spray on them?

[LJA]

Anything that's appropriate for diseases on ornamentals will work--there are a ton of things out there--check the gardening section at Lowe's or boxstore. Ortho comes to mind immediately (Orthonex, Daconil), but there are many other manufacturers. Floofy uses Cleary's (sp?) in Florida and has had good results. It's also a good idea to alternate between things that use different active ingredients--that helps keep anything that seems to persist from developing an "immunity" against the ingredient in just one product. Systemics seem to work particularly well for a lot of people. These get absorbed into the plant's tissues and do their job from the inside out. Their effects also seem to last longer than sprays that just remain on the plant's surfaces. There's also a product out called "Spreader-Sticker" which, when mixed with what you're spraying with, will coat the plant more evenly and help keep the disease control from washing off when you water. The downside is, it leaves a pale blue residue on the plants that's really hard to remove, but most people would much rather live with that than have to deal with repeated and more frequent spraying....

[Dana]

Euhm...what is rust?
I'm guessing it's not the same stuff that is covering most of my bicycle

So what is it? a kind of fungus?

[uncasteeb]

So what is it? a kind of fungus?<!-- / message -->

Correct a type of fungus.

[LJA]

LOL! Dana, yes, rust is the common name for a fungus, specifically Pucciniastrum epilobi, that attacks plant leaves (especially roses). It makes brownish colored, irregularly shaped spots or blotches that can be ringed with yellow where the affected areas meet healthy tissue, and the blotches are sometimes raised, especially on the leaves' undersides. It spreads (like almost all fungi) by airborne spores, and prefers warm, moist areas to proliferate (like at the centers of large, bushy plants, where there's little air movement). In greenhouses that aren't kept up to snuff, in other words, where there are lots of dead leaves, flowers, and debris littering the place, it can get pretty out of control.

Traci, if it really is rust and not some other, less nasty type of fungus, you need to isolate the plant, cut off the affected parts of the leaves, and spray all of your collection with fungicide, every week to ten days, at least three times. It's going to be a pain, I know, but once rust takes hold, it's hard as hell to get rid of by any other means.

[Dana]

ahhhh..thanks for clearing that up for me!

Traci, I hope you won't have to much problems with it..it sounds nasty.

[Aerides]

I just wanted to mention that I had something similar infect one of my best paph divisions. I cut off diseased tissue (ouch) with sterilized instrument and sprayed twice with Dithane (a systemic-you can find it on the web) at a one-week interval and that was that. Mixing directions on the label. I don't like using chemicals, and do so rarely, but if one of my best plants is being threatened, I don't fool around with home remedies.

P.S. For a spreader-sticker, you can use a non-phosphorus dish-washing liquid at about 1/4 tsp / pint. I use Ivory.

HTH,

John

[OrchidTraci]

ahhhh..thanks for clearing that up for me!

Traci, I hope you won't have to much problems with it..it sounds nasty.

It seems to be affecting 2 paphs , nothing else. I think I know how the one got it, and maybe the other got it from touching the other plant. The one (thank goodness) has a minor case and I hope to clear it up.