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Author Topic: Help on Yellowing and Leaf Curl on Rose Apples  (Read 1732 times)

MarkoS

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Help on Yellowing and Leaf Curl on Rose Apples
« on: April 30, 2013, 04:40:46 PM »
So first off, I get the impression that rose apples are not supper topics.  But they are a nice hedge with the neighbor.  My real fear is that this hedge is attached to my tropical orchard. 

So let me jump back last fall.  The seven rose apple trees had grown to heights of over 20 feet and were leaning over huge portions of mine and my neighbors yard.  He/ we thought it would be a good idea to make them manageable and trimmed them back to 12 feet.  We got new growth within a few weeks.

Now just this week I noticed a huge color shift in the trees.  Upon closer inspection, it looks like the new growth has yellow spotty leaves.  The older leaves are find with a few spots.  In fact I think I remember those spots from years before.  Any idea what this could be? (Note I'm in Martin County.)

Is it a disease or fungus?  Could it simply be shock and lack of nutrients?  Any thoughts on how to recover?  Do I need to worry about my other plants?  I see no signs of similar issues on them.

Thanks in advance.


pj1881 (Patrick)

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Re: Help on Yellowing and Leaf Curl on Rose Apples
« Reply #1 on: April 30, 2013, 05:27:50 PM »
Whatever it is my neighbors Rose Apple has it too. (Im in WPB FL 33415)

Greenhaven

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Re: Help on Yellowing and Leaf Curl on Rose Apples
« Reply #2 on: April 30, 2013, 11:36:17 PM »
Looks like Myrtle Rust. A bit of a concern here too as so many of our natives are susceptible. If you click on facts,photos and maps, link to prevention and treatment comes up. Unfortunately the regime for fruit/bushfoods has been removed. Don't know if this because of the safety of the fungicides involved. Are some general tips though.
http://www.daff.qld.gov.au/4790_20814.htm
« Last Edit: April 30, 2013, 11:39:34 PM by Greenhaven »

fruitlovers

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Re: Help on Yellowing and Leaf Curl on Rose Apples
« Reply #3 on: May 01, 2013, 02:29:03 AM »
Variously called: guava rust, ohia rust, myrtle rust, it is fungus Puccinia psidii. There are several different strains of it. Very big problem and hard to control, at least so far. Spores are spread in wind. Can affect other myrtaceaes, especially Eugenias, Jaboticabas, and Malay Apple.
Oscar

MarkoS

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Re: Help on Yellowing and Leaf Curl on Rose Apples
« Reply #4 on: May 01, 2013, 05:31:55 AM »
Thanks "Greenhaven" and Oscar for the diagnosis. 

It looks like here in Florida there's less concern.  A Master Gardner's post, "Fungicide application is often not necessary as the disease is seasonal and quickly passes."  But I'm going to hunt down a proper fungicide for "rust disease".  If for nothing else but to protect all the different jaboticaba's I have in the yard.

http://lee.ifas.ufl.edu/Hort/GardenPubsAZ/GuavaRustHomeowner.pdf

fruitlovers

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Re: Help on Yellowing and Leaf Curl on Rose Apples
« Reply #5 on: May 01, 2013, 05:57:05 AM »
Thanks "Greenhaven" and Oscar for the diagnosis. 

It looks like here in Florida there's less concern.  A Master Gardner's post, "Fungicide application is often not necessary as the disease is seasonal and quickly passes."  But I'm going to hunt down a proper fungicide for "rust disease".  If for nothing else but to protect all the different jaboticaba's I have in the yard.

http://lee.ifas.ufl.edu/Hort/GardenPubsAZ/GuavaRustHomeowner.pdf


Don't really understand why this fungus would be seasonal in Florida and year round problem here and in Australia? It's a very serious problem here, maybe because it is a newer introduction?
Here are some control measures recommendations from experiments done in Brazil to control it:
Sulphur fungicides and organic fungicides such as Parzate and Fermate did not control the disease. Bordeaux mixture and home-made cuprous oxide afforded very good protection to the fruits, although the latter injured leaves and fruits. The control programme recommended consists of an application of bordeaux mixture (1: 1: 100) after the first winter rains and another when the trees sprout. The treatment should be repeated monthly until December or January. [For a shorter account see H.A., 22: 1000.].
http://www.cabdirect.org/abstracts/19520304374.html;jsessionid=7E4AFC87762CB37183A5A5A5B63A649E
Oscar

 

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