Dying Mango tree - Please help

MattR

Hi everyone,

I live in Brisbane QLD and have a sick mango tree that I'd really appreciate some advice. I first noticed that it was losing it's leaves a few months ago with the leaves looking like in the second picture below.

I thought this was anthracnose and sprayed with some mancozeb and copper oxide plus using a seaweed fertiliser. This seemed to stop the leaf death and some new growth began sprouting on the tree.

However it now looks like something is eating all the new leaves leaving just the stalk as in the third picture below. Could this be an insect of some sort?

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Eric Frei

Could be a few factors at play, soil test will tell us if there is toxicity due to too much of something and deficiencies in other elements. Grass is a competitor and mulch would be better.

Start with a simple pH test.

Also a canopy spray of Confidor might be in order, many are suffering this year after the heavy wet recently and now a dry spell.

There's some fantastic information in the PDF I just loaded here.

Mango Tree Growing and Diseases

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Victor Lindsay

Take samples of the leaf, stem, and roots...send them to your local extension for a lab test. The test will tell you what to do. Try to sent stems that have both healthy and dead wood. Call the extension for additional instructions on how to send in samples. Don't spray chemicals until you know what your treating for, (the first step in any diognosis is to idenify).

Eric Frei

This is Australia, extension offices etc

If a pesticide is sprayed in the absence of a pest, frankly, so what? Nothing happens in the grand scheme of things. However, the probability is 99.99% that there is something unseen so spraying eliminates that possibility. All of that for say $10 why bother with diagnostics?

Confidor is broad based and low potency, it will kill 99.99% of the bugs at play.

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Victor Lindsay

Eric...you and i will always disagree in this area, and that's not a bad thing. If the client is going to send in soil samples, then the same lab will be able to test the leaf, stem and roots.

Victor Lindsay

here is a lab that could do the test, but not sure if it's in your area,

AGWEST Plant Laboratories

http://www.agric.wa.gov.au/PC_90014.html?s=1542272934

Eric Frei

Yes, they might but at a cost, but this is not USA with extension offices and diagnosis is expensive.

Confidor is dirt cheap and effective, spray the tree. So why do you want to waste more money for the same result ..... see if I am wrong then the client is still in front because of the cost of the diagnosis is more than the $10 for Confidor and if I am right they would recommend the same treatment.

I see this type of waste all the time, do tests and guess what, the treatment or mitigation is the same... big business and councils love to waste money on stuff like this.

Would there be any adverse effect to treating a tree with confidor that doesn't have bugs? NO

So do it anyway, it then eliminates one type of pathogen leaving bacteria and fungi as the likely others.

The soil test will tell us what is missing in the soil, and maybe what is there too much of. So could the tree benefit from an application of broad spectrum fertilizer? Yes and NO, because if it has a boron overdose already then you just might make things worse. Could it benefit from just some soil conditioning like Seasol? Yes, but we would still not know of any element overdose or absence. My methodical way is affordable, effective, logical, sound and timely.

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MattR

Thank you both for the quick replies!

I'll see if I can test the soil pH and report back. Will probably pick up some confidor as well. Eric is there a place in Oz to send samples to? Or better to get someone out to have a look?

Thanks again.

Victor Lindsay

Here in the usa, we have a problem with resistence on everything from weeds too pest, so yes, there is a negitive to just broadcasting a chemical that does not target the pest or disease.

Eric Frei

Matt,

Many mango trees are sick, and spotted gums are dying all over Brisbane.

We are in the middle of an undiagnosed epidemic and some species are copping it worse than others.

Kill bugs, kill fungi, fix the soil and hopefully the tree fixes itself.

I can arrange soil test for you if you like, a basic test is around $200 but if you want a bacteria or fungi test then it's way more and can take a month to culture.

Link to spotted gum disease which includes similar disease killing many trees in WA.

Spotted| Spotty Gum| Dieback| Disease| Brisbane - research

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Victor Lindsay

Wow! I just checked on prices for testing. The system in Aust is broken! No way anyone could afford that. Test here in the usa cost $25.00.

My appologies! Spray what ever you think will work.

Eric Frei

Well we don't, especially in an urban environment that likely has never had the treatment before.
There is also biological treatment but that is a longer slower process, something that can be instigated after the initial control, we are getting hotter and wetter with summer right on us.

There is also other chemicals that can be used but Confidor is safest. Carbaryl, Malathion, Mavrick etc can all be used, much room for rotation if required.

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Victor Lindsay

I just sent Hossein Golzar, an e-mail explaning the benifits of affordable test for non-farming samples. Home owners should get a break on testing.