Petal Blight on my Dpts.!

[Phal-lover]

Ok, so the title speaks for itself. My Doriteanopsis Ox Queen has petal blight. (Little brown spots on the flowers) What should I do? I really love this 'chid, and I want it to live.

[Bud]

petal blight= is a warm weather disease and normally does not become severe until May. It's those muggy, misty, rainy days that all the petal blight fungus go berserk and rot all those flowers that you waited a whole year to see. Since it is at the height of autumn, your flower must have been wet and the fungi feasted on it. Since it is fungi=you need a fungicide spray. I usually do a mixture of liquid cinnamon extract and soap combination with tepid water....but this must be done when you see it start a discoloration but your picture shows almost half of the flower is infected.
this fungus loves moist humid environment so this is why I do not wet the flowers and leaves when I water the plant=or I make sure they dry out fast with good air circulation.

[Phal-lover]

I'll try this, but I don't have a picture up. Once I spray the orchid should I wipe it or leave the water on?

[NYCorchidman]

Remove the affected flower(s) as the spots continue to release spores that will linger on in the growing area.
also, the spots will not disappear, it is a dead tissue eaten up by fungi.

Keep the flowers dry, do not mist on them.

There is a preventive spray to keep this from happening, but once the spots appear, there is nothing to do.
At home culture, you do not need to spray as dry air at most home usually keeps them at bay. only at large scale greenhouse with too much moisture in the air with poor ventilation, can this be an issue dropping the value of the flowers.

It is usually just unsightly but hardly ever deadly. so just pick off the affected flowers and you are done!

but how big are the spots?
Petal bright on orchid flowers are usually as tiny as pin head. If you see something bigger, it could be something other than petal blight.

[Phal-lover]

They are very tiny, but there are some clusters on a few.

[NYCorchidman]

Ok, sounds like a Botrytis attach then.
I would remove all the flowers that are spotted. They will serve as a source of future attach when the conditions are favorable for the fungal growth, although not very likely at dry home environment usually.

[Phal-lover]

Ok, I will/did. (but now my orchid looks sad with a huge spike and only one flower)

Also, I keep my orchids outside. I live in Florida, so outside conditions are mostly favorable. Will this cause more mold growth than inside?

[NYCorchidman]

With so much breeze, whether you feel it or not, outside, petal blight is hardly a problem outdoor.
It is mostly a greenhouse thing for orchids at least. I'm not saying it's not possible outdoor.

By the way, even in the south Florida, winter can get quite cold so I would watch out leaving phals outside.

The spike may sprout some more flowers. You never know.

[Phal-lover]

Ok, good.

I know, but right now it's 82 degrees. :P I bring them in when it gets colder. And by colder I mean 60.

And how would they grow? Off a side spike or buds straight from nodes?

[NYCorchidman]

It really depends, phals do interesting things.
Two most common things I've seen happen are:

Any of the "sleeping eyes" (dormant nodes) below the oldest flower (the one that opened first) may branch out and make flowers either shortly after the initial, or the "main", flowering fades, or long time thereafter.

The tip of the spike will continue to elongate to produce some more buds, but not many unless it is an equatris and its related hybrids which can make quite a bit of flowers continuously at the growing tip.
When you see the tip green, it's more likely that the old spike tip will elongate, but some spikes whose tip look like they are not going to do anything any more, may still add some more flowers.

Well, 82 is about ideal growing temperature for phals I would say and 60 is rather low but when the plants are gradually conditioned to that low, they won't be harmed. I still wouldn't put my phals under 65 minimum.