Author Topic: Rust on Myrtaceae in Hawaii  (Read 808 times)

HIfarm

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Rust on Myrtaceae in Hawaii
« on: May 24, 2018, 04:35:03 PM »
I've been wanting to post this for a little while but I have been waiting since I think Oscar would be the main respondent and I know he has had a stressful period with the volcano activity.

I have seen a pretty wide range of response of various species in the Myrtaceae alliance to our rusts here in Hawaii.  Many (so far) seem unaffected but a couple are really struggling.  Cedar bay cherry (Eugenia reinwardtiana) seems to be one that is having a tough time.  I have one tree of onionwood (Syzygium alliiligneum) that is growing like a trooper while its neighbor is now pretty severely stricken (greatly slowed).  So far, it has been a while and I am not seeing this second tree affected so perhaps this particular tree has some natural resistance.

I live in an area where there is a solid reservoir for this rust.  There are tons of rose apple (someone originally told me that they were mountain apple but I now hear that they are probably rose apple) in the palis that are severely affected (they "kind of" grow, slowly and weakly, but I have never seen fruit on any).  Unfortunately, it is all around in the area so there is no way to eradicate them.  I'm sure that there are others in HI in the same boat as me.

Can we start a list of Myrtaceae that are wise to avoid in Hawaii for rust susceptibility? 



John


fruitlovers

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Re: Rust on Myrtaceae in Hawaii
« Reply #1 on: May 24, 2018, 04:57:44 PM »
I think there are at least 4 different strains of this rust, so it can hit different plants in different areas. At my place worst hit are rose apples, cedar bay cherry also badly affected. Some of the mountain apples and wax apples have a hard time. Jaboticabas occasionally affected.
Try to remove affected plants, especially ones that are upwind from other plants. Put vulnerable plants in sheltered areas upwind. I've heard bordeauex mix is effective against this rust but haven't tried it. Might need to do several applications.
Oscar