How to treat Silver Princess leaf disease?

[Merph]

Hi 

Anyone have a solution to this leaf problem.  It is only on one of the silver princess trees (and we have at least 25 on our block). I can't find anything online or via google

Your help is appreciated 

 

[mich1972]

Good afternoon @Merph I love these beautiful trees , looks like a bacterial / fungal infection. Best to spray them with a fungicide that has copper in it. Yates Liquid Copper is a good one. I’m going to tag in @Noelle to see what she recommends 🌿🙂

[EricL]

Hello @Merph 

Welcome to the Bunnings Workshop community. It's sensational to have you join us, and thanks for sharing your question about your Silver Princess.

It's great that you've received excellent advice from @mich1972. A possible second cause for the spots on the leaves are Eucalyptus leaf blister sawfly larvae. If the affected leaves have raised, blister-like patches (as in your photo, where translucent areas with reddish-brown spots are visible when backlit), this is almost certainly due to Eucalyptus leaf blister sawfly larvae. These tiny larvae feed within the leaf tissue, creating the red-brown blotches and translucent patches. The damage can look fungal, but if you hold the leaf up to light, you’ll often see small larvae or tunnels within the affected area.

Unfortunately, soap spray is not an effective solution for controlling eucalyptus leaf blister sawfly larvae because the larvae feed and live inside the leaves. Insecticidal soaps only kill pests on contact, so the spray cannot reach the larvae inside the leaf blisters. For a small, localized infestation, I suggest manually removing and destroying the affected leaves. This will kill the larvae inside the blisters and prevent them from completing their life cycle.

But I am keen to hear what @Noelle's diagnosis might be about the patchy leaves.

If you need further assistance, please let us know.

Eric

[Noelle]

Hi @Merph 

Looks more like a disease rather than sawfly larvae to me. I'd go with @mich1972 's diagnosis and treatment and see what happens/

[Merph]

Hi, thank you all for your contributions.  I have been told that it could be myrtle rust and treat it with Yates 150g Mancozeb Plus Garden Fungicide And Miticide.

I will try it during the week and see how it works

[mich1972]

Hi @Merph I don’t think it’s Myrtle rust , as the spores are yellow and bumpy. Mancozeb Plus is a really good fungicide so there’s no harm in using it and see what happens. My understanding with Myrtle rust is that it is really bad and spreading quickly. I can’t see any yellow spots in the photo ? I would like to ask @Noelle 

[Merph]

Thanks Noelle

I can't see yellow lumps, but still worth spraying to see if it will control the problem

[Noelle]

I would agree @mich1972  that it does not look like Myrtle Rust. I'd agree too that an application of mancozeb would be beneficial as it's a useful control for a number of fungal diseases.

[mich1972]

Thank you ☺️