Violet Bramble Rust...

[Jason Green]

Evening WAB'bers,

I have a lot of bramble in the garden, probably the most widespread plant, and since having seen a random picture at the top of the forum I've recognised a feature on a lot of it - violet bramble rust, Phragmidium violaceum!

I've read this is used as biological control with regards to invasive brambles. The bramble holds a lot of invertebrates... are these at risk now, and will it eventually kill the plants??

Thanks!

Take care,

Jason

[Chris Yeates]

hi Jason

a small note of caution - there are two Phragmidium species on brambles: P. violaceum and P. bulbosum; if yours is very virulent (see attached for view of mostly the uredinial stage) and strongly violaceous on the upper surfaces of the leaves corresponding to the rust areas of attack below I suspect your fungus is the former (a quick look at the spores of the telial stage under the microscope enables an easy confirmation).

as you can see from the photo this attack is very heavy (including on the flowers) yet the plant is fruiting happily elsewhere

I am extremely interested in the rust fungi and have occasionally seen plants which have been more or less killed by them, but these have nearly always been stunted annual plants; I don't think that using a rust to kill invasive brambles would work - it is not in the interests of a parasite that the host is killed after all (though death usually occurs in fungi which attack invertebrates)

cheers

Chris

[Jason Green]

Thanks Chris, I'll get back out tomorrow and check the colour, spread, etc. In a bid to keep the brambles, would it be possible to eradicate the parasite, or wouldn't this be required??

The underside infection seems to be black/yellow.