Question

october sun plums   I have a block of october sun plums about 3 to 4 week ago th eleaves started getting a lot of hole like shothole or bacterial spot but both of there have been tested for and showed niether ,then about 2 weeks ago black spots started showing mostly on the bottom of the fruit then the black mark splits and leaks gum leading all the way back to the stone.???the only idea we have come up with is an amino food (vitalem forte] the one row i didnt spray hasnt got any of that splitting.we cant see why a amino acid fert would cause that reaction.if any more info is needed please ask.   Cheers Bo

Answer
Hi Bo,

The shothole symptom you describe can be caused by a bacteria or a fungus.  I'm not sure how they were tested, but if they only checked for one organism, it could be the other.  The fungal disease (Coryneum blight) that causes shothole can cause damage on the fruit.  Please see these links:
http://www.jlgardencenter.com/uploads/handouts/CoryneumBlight.pdf
http://utahpests.usu.edu/ipm/htm/advisories/treefruit/articleID=4742 (scroll down a bit)
Do you think this is similar to what you've observed.

I also wondered if you've checked for insects inside the damaged areas on the fruit.  Insects such as codling moth cause damage a little like your picture and will attack fruit of prunus.  Anytime Prunus fruits are damaged, they will usually leak gum, and it could be an insect or a pathogen that caused the wound.  If you scroll down a little on this site, you can see a picture of codling moth damage.  You may find the little critter in your fruit.
https://utahpests.usu.edu/IPM/htm/advisories/treefruit&articleID=13372

Hope this helps.  Please let me know if you have more questions.  It's hard to tell from your image which problem it could be.  You can send more images if necessary or ask additional questions if needed!

--Jen