What are red spots on lilly pilly leaves?

[deeeff]

hello, approximately one month ago a couple of the plants in my Lilly Lilly pilly hedge started having there leaves drop off from mostly the external and highest leaves. 

I suspected a caterpillar attack as this has happened before and sprayed the products with success ultra. 

The leaves have continued to drop since and seemingly even more plants appear afflicted, almost all of the plants (aside from the very healthy deep green ones) leaves are covered in red dots. What is also odd is that there is new growth emerging despite the plants seemingly unhealthy state. The tips of plants seem to be browning and dropping leaves which spreads from the tip towards the trunk but new shoots sometimes emerge elsewhere.

I can’t seem to find anything similar to this problem on the internet, the plants are the goodbye neighbours acmena smiithi variety. I have attached some pictures for reference. Any help would be much appreciated 

 

 

 

[EricL]

Hello @deeeff 

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

It appears to be a type of rust infestation, but just to be sure would it be possible for you to post a close-up photo of one of the heavily infected leaves both at the front and back? This will allow us to better assess the infection. We'll then be able to recommend a remedy for the plant.

Can you please also tell us what your watering habits are and how often do you fertilize the plant? Any other information you can share about what's been happening the past few weeks with your plant will allow us to give you a better diagnosis.

I also suggest having a quick look at this guide: How to diagnose and revive a sick lilly pilly by @Noelle. 

If you have any other questions we can help with, please let us know.

Eric

[deeeff]

Hello, 

I fertilised the plants twice this year once at the beginning of spring and once again approximately two months ago when I planed two new trees to fill gaps in the hedge. I typically water the plants twice a week in warmer weather with quite a heavy watering, sometimes watering in the early evening (which I am now realising may have been a mistake). I have 24 plants in a hedge row and the spotting seems to have now infected almost all of them in some capacity though I have lessened my watering of the plants now that the weather has cooled down. The plants at the lower sections of the plants appear a deep healthy green still but the upper outer segments are yellowing where the spotted leaves are, the plants are still producing new growth though but are losing leaves faster then it is produced. I have attached the photos as requested, thanks for all your help. 

 

 

[MitchellMc]

Hi @deeeff,

I'd agree with my colleague that it has the appearance of a fungal infection and could be Myrtle rust. Have a look at this discussion: Lilly Pilly Cascade - spots on leaves. You'll note our horticultural expert @Noelle has made a recommendation on appropriate steps to take. Hopefully, she'll be able to chime in and let us know her thoughts.

Please let me know if you have any questions.

Mitchell

[Noelle]

Hi @deeeff 

My first reaction was potentially myrtle rust but then the leaves also appear to be exhibiting signs of a major nutritional deficiency, which could why the plants have succumbed to disease in the first place. Healthy plants are better able to resist diseases. It's vital to take action immediately on both fronts.

[MitchellMc]

@deeeff,

So, it sounds like you'd be best to contact your "State's Department of Primary Industries or equivalent as soon as possible to firstly obtain an accurate diagnosis and then what action needs to be taken". Provided it is not myrtle rust, you should start a feeding regime to restore nutrient deficiencies.

Mitchell

[deeeff]

What is strange is that the lower growth of the plants is a deep dark green and look healthy, some of the unaffected or less effected plants are also a deep dark green, it is only the leaves that are affected that have yellowed and are dropping. I have had a look at Myrtle rust symptoms and your correct it does appear the same but I am located in Perth Western Australia where Myrtle rust hasn’t been detected previously, I will take the advice to alert the appropriate parties, thanks everyone for your assistance. 

[MitchellMc]

If we can rule it out, @deeeff, we can then work on resolving the issue. Regarding the attacked growth, I also noted that myrtle rust attacks actively growing shoots, stems and other soft young tissues.

"This fungus was found in Australia for the first time in 2010 and was detected in the northern part of Western Australia in June 2022." So it's not entirely off the cards that it has made its way to Perth. Let's hope it's just something that looks similar.

Mitchell

[deeeff]

Thanks a lot mate, I have contacted them and will follow up on this post when I have information one way or another, I’ve also attached another picture which shows the contrast between affected and unaffected leaves. 

 

[deeeff]

Hello everyone, had this investigated by the department of primary industries and agriculture in WA and they’ve said that it is not Myrtle rust, it is some form of fungal infection but as to exactly what they are at this stage unsure and the samples are undergoing further testing. The dieback of the plants seems to have slowed down in winter but the leaves are dulling further with a lack of new growth, is there any steps I can take now knowing it isn’t Myrtle rust on the plant ?