Mysterious organism on RMJ

[Gaijin]

I was inspecting one of my Rocky Mountain Junipers a bit closer than usual today and discovered this. Can someone help me identify it please? It is only on one pad. Fortunately it's the lowest pad on the lowest branch, and can be cut off if necessary without compromising the styling.

 

[quietobserver]

Possibly the beginnings of cedar Apple rust.

How to Avoid Cedar Apple Rust in Conifers | American Conifer Society

Learn how to avoid or control rust fungal diseases of cedars and pines.

conifersociety.org

 

[Wires_Guy_wires]

I second for apple cedar rust. Cut it off and clean your tools.

 

[penumbra]

Yes^

 

[Gaijin]

Possibly the beginnings of cedar Apple rust.

How to Avoid Cedar Apple Rust in Conifers | American Conifer Society

Learn how to avoid or control rust fungal diseases of cedars and pines.

conifersociety.org

That was a suspect, but it didn't look quite like some of the pics I've seen. Thank you for the link, good article. I'm sure you're correct.

 

[penumbra]

That was a suspect, but it didn't look quite like some of the pics I've seen. Thank you for the link, good article. I'm sure you're correct.

This is the way it starts before it gets humongous. I have seen a lot of this in Virginia.

 

[LanceMac10]

Hopefully your not too attached to the tree.....

 

[PiñonJ]

 

[Dav4]

Definitely Cedar-Apple rust. I've been fighting it on one of my RMJs for almost a decade. I've been remov ing infected branches as I notice the galls, and I've been applying clearys granular systemic fungicide every spring along with preventative spraying... it didn't really help much. Anyways, between that and tip blight, which kills the tips of multiple branches every year, I've begun grafting shimpaku onto the two RMJs I have left.

 

[Gaijin]

Definitely Cedar-Apple rust. I've been fighting it on one of my RMJs for almost a decade. I've been remov ing infected branches as I notice the galls, and I've been applying clearys granular systemic fungicide every spring along with preventative spraying... it didn't really help much. Anyways, between that and tip blight, which kills the tips of multiple branches every year, I've begun grafting shimpaku onto the two RMJs I have left.

View attachment 291573View attachment 291574

Hmm. Not very encouraging. So judging from the last couple posts, you feel it's not just going to go away with removal of the infected branch? Something I'll be fighting more or less forever?

 

[Dav4]

Hmm. Not very encouraging. So judging from the last couple posts, you feel it's not just going to go away with removal of the infected branch? Something I'll be fighting more or less forever?

I believe environment is everything when it comes to growth habits and prevalence of disease. RMJs are from colder, semi-arid climates and the extra humidity down in GA certainly helps the fungus take hold. Without knowing where you're from, I can only guess. Personally, due to the susceptibility to fungal disease and the predisposition to rank, lanky semi juvenile growth here in GA, any RMJ headed into my garden in the future will be destined to get new foliage.

 

[Gaijin]

I believe environment is everything when it comes to growth habits and prevalence of disease. RMJs are from colder, semi-arid climates and the extra humidity down in GA certainly helps the fungus take hold. Without knowing where you're from, I can only guess. Personally, due to the susceptibility to fungal disease and the predisposition to rank, lanky semi juvenile growth here in GA, any RMJ headed into my garden in the future will be destined to get new foliage.

I think the Shimpaku grafting might be the move to make. I'm not willing to chuck it in the bin or burn it just yet. Thanks for the reply.

 

[Wires_Guy_wires]

There are multiple varieties of apple cedar rust.
Here's an article about treating one version: http://agris.fao.org/agris-search/search.do?recordID=CN2014002461

University of Kentucky advises to do this:

Control: Eliminate nearby red cedar and common juniper where possible, or remove and destroy cedar rust galls and rust-infected juniper twigs. Spray with fenarimol, propiconazole, chlorothalonil + fenarimol, triadimefon, mancozeb, or mancozeb plus thiophanate-methyl. Make 3 applications at 10-day intervals beginning when orange rust masses develop on junipers (April through May).

I've been succesful at stopping new fruiting bodies to form with thiphanate-methyl (systemic soil drench, applied once a year in spring) combined with copper sulfate (applied twice a year, spring and summer) and biological warfare treatment with Trichoderma viride (applied randomly in the growing season, but at least three weeks after any other treatment).
I've become a big fan of the trichoderma viride, since it also helps a whole lot combating stuff like mildew.

 

[Gaijin]

There are multiple varieties of apple cedar rust.
Here's an article about treating one version: http://agris.fao.org/agris-search/search.do?recordID=CN2014002461

University of Kentucky advises to do this:


I've been succesful at stopping new fruiting bodies to form with thiphanate-methyl (systemic soil drench, applied once a year in spring) combined with copper sulfate (applied twice a year, spring and summer) and biological warfare treatment with Trichoderma viride (applied randomly in the growing season, but at least three weeks after any other treatment).
I've become a big fan of the trichoderma viride, since it also helps a whole lot combating stuff like mildew.

Does trichoderma viride have a trade name it's sold as? It would probably be a different name in the Netherlands perhaps. I have mancozeb and copper sulphate on hand, maybe some of the other stuff, I'll have to check the active ingredients on the different bags of chemicals I have. I just applied a systemic called Bonide 'infuse'. The active ingredient is thiophanate methyl. (as you mentioned) I applied about a tablespoon over the soil surface. We are expecting a good rain today to water it in. I'll follow your protocol, thank you. Ultimately I will probably do the grafting, but obviously that's not an overnight process, and I want to maintain the health of the tree in the meantime.

 

[Wires_Guy_wires]

Trichoderma viride as I bought it on ebay, came from Russia under the tradename Trihophlor or trihoflor.
I'm not a 100% sure that it works for rust, but I'm a 100% sure that it does no harm.

 

[crust]

copper-based spray to control. Copper Octanoate. remove fruiting bodies.

 

[NOZZLE HEAD]

First.
If possible remove Roseaceae secondary hosts from the area, or inspect them mid summer and remove leaves or fruit that have rust like symptoms. There are fungicdes that are registered for treating these as well but the choice depends upon what their use is, ornamental or for fruit.

Second.
Treat with a fungicide. Eagle 20 EW at 6 to 12 fl oz/100 gal water. Foliar spray. Mid summer when spores are shed from other hosts.
Addition of a drench fungicide will provide incremental control.
copper sulfate will only be effective if applied precisely preceding spore release from the alternate hosts (Roseaceae), not recommended due to short active life, no systemic activity, and potential for phytotoxicity.