It's not powdery mildew, that usually shows up on the leaves and they just look greyish and maybe a bit powdery.

I hate to say it, but it looks like bird poop. Maybe a bird was standing on the rose canes?

ditto

Bird poop would be my guess, as well. From the quantity, do you have a big tree and an owl nearby?

Remember not to look upward at the sky while in your garden.

Its the funniest thing we do have owls but there is no big tree close to this rose and its not that big for an owl or any bird to sit on, but maybe. I have this white stuff on other roses too, it is right around the leaf buds and I took one leaf bud off and there was a drop of clear liquid that came out and dripped down the cane and after it dried it was this white color. Does my rose have a runny nose?? LOL just kidding.... anyway I cannot imagine what it could be except I did give these roses some epsom salts on Friday, but not much maybe a tablespoon for each rose, and Saturday it rained alot but I don't know..... could it be the epsom salt coming out of the bud eyes? This is too strange.....

hahaha you're funny Karl, I just saw your post. I better start wearing a hat!

Oh,That bird must be huge..reminds me of the 300 lb. canary
"Here Kitty, Kitty...."

It's not drying spittlebug foam, is it?

If you don't think it's bird doo-doo, take a sample to your county extension agent for a diagnosis. then let us know.Do you have a lot of seagulls? Don't know how but they crap out more than they eat.
If their diet includes a lot of fish, their droppings are really oily and gloppy.

Thanks everyone. You guys are funny.
Karl I do live near the ocean and we do have seagulls, and they are like buzzards they eat everything! I will definitely be keeping my eyes in the sky.
I sprayed some Bayer Disease Control on them last night and this morning the white stuff is almost gone, My one rose cleared up completely. But the spray itself could have just washed it off if in fact it is bird doo. I was thinking that it could be Powdery mildew, and since I don't have that many leaves it decided to develop on the canes? I will just have to wait and see if it comes back.
Again thanks for everyones' help, appreciate it.

Mildew attacks only very young, soft stems along with young foliage and the bases of buds. It is powdery or flocky-looking. That pic doesn't show mildew or any fungus I've heard of.

First time I got it on my roses it stumped me too. It is in fact powdery mildew. I got it on my bands and treated with copper.
Masha

Here is a link that might be useful: {{gwi:241684}}

Oops, thanks Masha, I retract my dogmatic statement, but I've never seen that in 30 years of looking at roses. Yours clearly is PM.

I never saw it on my roses either. The only time I got it was on the bands that came from RVR and the people at RVR said it was because of an abrupt change of environment (from cold Oregon to hot San Jose).
Masha
P.S. That site, sactorose.org is really helpful to me as it provides good quality pictures of lots of things that can be wrong with roses. Whoever put this site together has my sincerest thanks.

Baldo Villegas's site is a treasure. He has been known to post here.

The OP described her white stuff as a "goo," so I still question whether it is PM.

Thanks Masha, I have a feeling it is PM. We had a period of fog on Saturday night and it was somewhat warm for a while then the temps dropped very fast so maybe it came from that.
I don't know if it is goo or not, I didn't really touch it to see if it is sticky. I guess I should have used another word. Chalky is the best way to describe it.

If it's coming from sap that is drying white, it's not powdery mildew. Powdery mildew doesn't ever invade the rose's inner tissues and is never found in the sap.

Furthermore, while Mr. Villega's site includes a picture of an infected cane, he also points out that in a climate with a winter the fungus goes dormant, residing in black structures found on infected leaves lying on the ground.

That isn't powdery mildew, no matter how similar the appearance to Mr. Villega's picture from California where winter is not at all like it is in New Jersey.

I also agree with everyone that suggested bird poop and NOT PM or spittlebug foam. The ultimate test is to see if the white material can be washed off with water. I wouldn't be afraid to get my fingers in there to wash it off. I do not agree that it is powdery mildew as PM mycelia usually overwinters around the prickles/thorns and not as in the picture. Also, it cannot be spittlebug foam because when it dries it does not have the white chalky material as is in shown in the picture. The dried up foam also washes away readily. The spittlebug nymphs also produce copious amounts of foam. If you wash it off, the nymph will produce more within a few hours. The other possibility that nobody expanded on was sap but sap is usually does not dry up white like in the picture.

I would be more than happy to see samples and see if it is indeed PM. If I can't do it, I will share it with my plant pathology colleagues for their own diagnosis. Please email me directly and I will give you instructions on how to mail me a sample for diagnosis

Here is a link that might be useful: Baldo's Bugs & Roses Website

Thank you so much, I sent you an e-mail.

And as to quantity of poop from one bird:
Last night I left the mower I use to drag stuff around the farm under a different tree.
There was a bird in that tree over that mower last night.
The amount of stuff from your bird doesn't hold a candle to the amount from my bird.
That is all.

Ann

LOL.

I have powdery mildew on my canes - it gathers around thorns on some roses. I have to spray tomorrow as I have alot of rust and the PM is coming on fast now that it is April. I hate spraying but I will tomorrow morning.