Browning Canes

We were just in the garden doing some cutting back and came across this (see pics) on one of our roses. Its nothing we have ever encountered before in our roses. Its on two of the stems, on the one bush and it goes all the way from the top to the base where the cane is joined in the root stock. Anyone have any ideas?

Top
[You must be registered and logged in to see this link.]

Bottom
[You must be registered and logged in to see this link.]

Cain
[You must be registered and logged in to see this link.]

Cain split open
[You must be registered and logged in to see this link.]

[You must be registered and logged in to see this image.]

....any takers?

Borers?

Thank you for taking the time to let me know, Gary....I appreciate it

It looks like boer damage. Is there any small hole with what looks like saw dust around it? We get them in Mrs BR Cant. No other rose just it. We have several of them and nearly all of them get them. We inject some Rose Shield directly into the stem where they are active and it kills them. They do come back after a while but I am not sure where from.

actually we found it when I cut a Governer Macquarie can that was almost 2m tall. The cane was healthy and flowering at the time and the first cut was about a mtr of the union when we notice it and then cut it at the union, where it showed. This is my first borer, so I did not know what it was

Help is on the way, will post morer info shortly.

I checked with Lee and she agrees. It looks like borer damage. The rose can look healthy but the stem will sudenly brown off and die.

Also I was wrong with what I said we used. We use Malathion Garden Spray except we don't spray it we inject it into the stem with a syringe. No needle just put the syringe into the hole (or make one I guess if you cannot find where they got in) and inject some of the liquid into the stem.

There is a fair bit on the net. Just google rose cane borers.

[You must be registered and logged in to see this link.]
This site will be very useful I think now and in the future. I will place the link in "Whats Bugging My Roses" as a sticky. A thanks go out to Kim for alerting me/us to it.

I would have expected to see a hole drilled into the upper end of the cane for there to be a borer. I would also expect to see a tunnel bored from top to the one in the bottom as evidence, unless I'm not seeing it in the photos because they aren't close enough or it doesn't show. When I've found borers, the pith hasn't been darkened and discolored as this one appears. It feels more bacterial or fungal to me. Unless it is Flat Headed Apple Borers, I've not encountered canes splitting open from borers, but I have had them split because of canker.

Thanks Kim,,,the top end of this cane had a large bloom on it and I cut this cane in half to have a look inside. From the outside you would have thought this was a perfectly 2mtr healthy cane....till I pruned it

That seems very odd. If it was a borer, you would see an entry point. Might the rose have been frozen at all? Something has killed the pith and that would have to be disease or temperature.

Frozen...were unlucky if we get down to 5c, otherwise we average around at night 10-12c. To be quiet honest, I could have missed the entry point as I did not know what I was looking for or at.....

John, is there any more of the cane still on the plant ? If so cut it down in 25mm sections till you find new wood (hopefully). Cut/break each section open, trying to find the culprit.
Can you see sawdust in the section from say a boring type of pest. If it is a pest try and get a photo of it. Is it the only cane that has it ?.

I had two canes with it and if you look at the photos, the bigger darkest color(picture 2) was cut at the union bud. So two canes had this markings at the union bud. Im thinking that if there is a critter in there it might be in the union , and might eventually take out the rose

John, when you say bud union, do you mean where the rose was grafted/budded to the rootstock

Thats it...

John, did the browning go into the union and if so, is there any dust or just browning. If you can see dust I would poor/syringe Metho down the hole.
What chemicals have you got on hand.
IMO I would get a very very sharpe knife/scalpel and take slithers off the effected part. You won't kill the union as long as you find the last part of the trouble.

Yep they both went into the union....I do have metho and various other chemicals.......anyone in particular...

John as said earlier I would take slithers off to see how deep it goes into the union, if there is dust, metho/pesticide. If browning a strong dose of fungicide(what have you got)