Royal spotting

[enigma99]

Noticed some spots have been growing recently on my regia on one leaf. Should I be treating it with anything? Can it spread?

 There hasn’t been any frost yet this winter so I am hoping it is just the cool weather and it is benign. 

Pic was hard to take as the branch is a good 16ft up in the air. 

Thanks

 

[Anthony_B]

Looks like some kind of fungus to me, maybe caused by prolonged cool, damp conditions.  Have you tried a copper fungicide or some neem oil?  Those are two potentially organic treatments that shouldn't have any ill effects and only benefits.

 

Use these only prior to sunrise or at sundown (sundown preferably).  Neem oil, specifically, has been known to stain leaves if applied during high sun.  You want them to sit on the fronds overnight and not get "burnt off."  I do my sprays in my garden either at 8AM or 4PM around this time of year.

Edited January 16, 2018 by Anthony_B

[quaman58]

It just looks like cold damage to me. It always reminds me of over ripe bananas. I see it every winter on species like Hyophorbe v. & Dictyosperma. They get temps just low enough to be unhappy, usually once it drops below 40f. Unless things get colder, yours should be fine.