Yellowing Japanese black pine

Hi everybody,

One of my JBP is yellowing.
It’s on the entire canopy with branches more severely touched than others.
It happened suddenly, I repotted it one month ago.
There are points of sap on the tips of needles

Do you think of a fungal issue or I did something wrong when I repotted ?

Any advices ?
Thank you !

@Vincent - I did a search for “sap on tips of needles” in the library and this is the video that showed up.

Dothistroma Identification


I’m sure somebody with more knowledge than I will let you know for sure.

Looks like standard needle cast. Those would have been infected last year as they elongated from the candle. To prevent this year’s needles from getting infected, you need to apply fungicide (Daconil or Copper) as the new needles form but before they harden off. Once they form the waxy cuticle, they are far less susceptible.

Thank you I just watched this video ! :slightly_smiling_face:

Thank you!
Do I have to apply copper once or 2 / 3 times ?
I isolated it from other pines.
I thought yellowing with needle cast happened in fall ? Is it normal that it happened 1 week ago ?

I re-apply copper if it rains. Daconil is supposed to leave a coating, so follow label instructions.