Phal losing leaves

[sewcrazy64]

I bought this phal in Sept. '09. I repotted it in November, it started putting on a new leaf in December, and has seemed healthy until last week when I noticed the oldest leaf was starting to yellow.

I assumed the old leaf was dying because the new leaf was coming on. Today the leaf fell off in a way I've not seen before. Usually when a leaf drops, the entire leaf turns yellow and completely detaches from the plant stem. This leaf was still half green & when it fell off it left the leaf base attached to the plant stem (see photos). Today i noticed that the remaining old leaf is now yellowing at the base and is starting to break off (see photo #2). I also see what looks like some type of lesion at the base of the leaf.





I am very careful not to get the crown wet when I water. Please tell me what kind of problem this phal has and what I should do.

Thanks,
Dana

[Alana]

Looks like it was broken.. any inquisitive cats or hyper doggies in your home?

[orchidaddict789]

It looks like some sort of leaf rot. The lack of air movement, cold temperatures, bad medium, or possibly cold/wet (not necessarily wet in the crown) may have spurred the fungus. Sometimes fungal infections can appear right out of the blue. I can't tell if it has progressed to the crown. In the photo it looks like the topmost leaf is still fine, which is good. You can try pouring 3% hydrogen peroxide over the plant, or possibly soak the plant in it for a couple of minutes. Do this in the morning...dab with paper towels afterward to dry out the leaves. If the rot is still progressing, spray with a fungicide (people say physan 27 is good).

[sewcrazy64]

Thanks for the advice. How likely is it that the other orchids it was grouped with will get the fungus? Should I treat them preventively?

If it turns out that I need to use a fungicide, I don't have Physan but I do have a general purpose fungicide. Will that work?

Thanks,
Dana

[Alana]

Always a good idea. Spray them down with a good fungicide.

[sewcrazy64]

I don't have Physan, but I do have Daconil and Benomyl fungicides. I read some very old posts here that Daconil and Benomyl fungicides are ok to use on orchids. is that still true?

Thanks,
Dana

[margo]

I would soak it in Peroxide for 10-15 min. Works best for me...

[sewcrazy64]

Thanks Margo! Yesterday when I repotted it I soaked it in peroxide for 30 minutes. Is one time enough or do I need to repeat? If so, do I rinse or wipe off the peroxide or just let it dry?

Thanks,
Dana

[margo]

Once should be enough. I never rinse it off, but I don't let it go in the crown. If I need to pour HP in the croun I dry it with paper towel. If you already did that just leave it bare root for now and only spray the roots every morning. Let the plant get some moist, but don't leave it wet through the night. Give the plant good air movement and low light.

[sewcrazy64]

**UPDATE**
This morning I removed the diseased leaf to expose the stem. I saw that the base of the one remaining leaf was also rotten and then it just fell off. The stem looks like it has some black areas too (see photo.)



I think I know the answer but I will ask anyway. Since the roots appear to be healthy, is there any hope that the plant will put out new leaves? (I'm so sad. This is my family's favorite orchid.)

Thanks,
Dana