How to treat lilly pilly with mottled leaves?

[dars]

Morning,  We had a row of 5 lillie pillies die.  The leaves changed colour and then fell off.  We have cleaned and replanted and the new lillie pillies have been doing very well (last 4 months)  however the same issue is starting up again.  I've attached a picture of the leaf, can anyone tell me what this is and what the treatment is? 

 

 

[MitchellMc]

Welcome to the Bunnings Workshop community @dars. It's wonderful to have you join us, and many thanks for your question about Lilly pilly care.

I believe that is Black spot, which is more commonly seen on roses. It's a fungal disease that can be treated with a fungicide. 

Ensure the plants have good air flow around them and clean up any fallen debris and dispose of it. Black spot thrives in moist, humid environments. Weakened plants are also susceptible to it, so ensure you fertilise adequately. You might like to apply some Powerfeed to them.
 

Let me tag @Noelle, @mich1972 and @mashthyme for their thoughts.

Please let me know if you have any questions.

Mitchell
 

[Noelle]

Hi @dars 

Yes, the leaves do look lilke they're affected by a fungal disease so Mitchell's advice is, in my opinion, the best way to go.

Additionally, I'd look at cleaning up the soil under the lilly pillies, raking up dead and fallen leaves and other leaf litter to remove potential sources of the disease spreading. Infected leaves will develop spores that can become airborne and blown on to healthy leaves on the trees. Removing all fallen leaves is just another step in controlling fungal diseases. Don't add this leaf litter to the compost bin or other parts of the garden - bag it and put it in your household rubbish bin until all signs of infection have disappeared.

[mashthyme]

hi there @dars and thanks for tagging me @MitchellMc 

I'm not 100% sure that it is a fungal blackspot, it looks somewhat bacterial also because of its uniform appearance. I did a Google search and was thoroughly disappointed with the results. I couldn't find anything about black spot or bacterial diseases for Syzygium australe only information for rust (it's not rust).

So I went to my university library but unfortunately they have just transitioned me to alumni so I need to pay $20 for my subscription to their library (which will still limit my access) and I don't have the money for that this fortnight, but I'm aiming to get it very soon so I can subscribe (to my life-line).

thanks