Shiva wrote:
torgo wrote:

Botrytis is NOT a bacterial infection. It's
a fungus.

You're absolutely right. I was confused because I saw Cass post that
canker is a bacterial infection, and thought I remembered her posting that
botrytis is a bacterial infection. I have always been confused about the
nature of canker. This explains why my regular use of fungicide keeps this
hideous crap out of my garden.

Sadly, I know entirely too much about botrytis. When it just affects
the aging bloom, it often looks like this:

http://home.earthlink.net/~cbernstei...s/botrytis.jpg

On a light pink rose, I doubt that someone would see browning petals
and not see any of the polka dots that are so characteristic of the
scourge. That's certainly my experience, at least. On a dark red rose
it can be hard to see spots before the petals brown, but on a lighter
colored rose, those polka dots are visible long before the rot sets in.

Yes, I've seen the effects of Botrytis cinerea in many forms,
most of which are quite disgusting.

So says another poster who does not protect his or her roses from fungal
disease by spraying with a fungicide. I would not know, because all I have
ever seen was the telltake bloom rotting on the stem. After that, my
fungicide apparently kicks in. I rather like that.

I'm fairly certain that not all petal rot is caused by botrytis. Some
just can't take untimely rain, gather the rain in the bloom, and
self-destruct from the inside out, as described by Saki.