growth on Toka plum

Question: Some of my plums have a black, crusty growth on them.  what is the disease and how do I treat it?  Also, are these safe to eat if I remove that growth?

responder: An Ask Extension Expert Replied August 16, 2024, 5:15 PM EDT
response: Good afternoon! Unfortunately I cannot determine what is wrong with your plum just from the photo. Is this happening to all the plums? Is there any damage to the tree? Is the damage showing up before or after harvest? When you cut it open do you see anything in there? When did this start? Is there any damage on the unripe fruit? If you could send a few more photos of the inside of the peach, the tree, and close up of the damage I can help out more! Thanks so much, Rachel

responder: The Question Asker Replied August 17, 2024, 11:21 AM EDT
response: Thanks for your response Rachel.  I have attached more photos.  The tree is healthy (aside from some aphid damage to leaves); there are no growth on the tree branches or trunk.  Not all the plums have this growth, and it seems to be just on ripe plums (prior to picking).  Those plums show rot much quicker when picked and I have included a picture of that.  There is nothing inside (no bugs, worms, etc.). The picture of plum4 is the original one I sent you split open and there is no internal damage.  Once I take the growth off the harvested plum, it shows rot quite quickly.   Hope you can help, I love these plums.  The tree is 5 years old.   Thanks again for your help. Patricia Dormeyer Arvada, CO   From: ask=<personal data hidden> On Behalf Of Ask Extension Sent: Friday, August 16, 2024 3:15 PM To: Patricia Dormeyer  Subject: Re: growth on Toka plum (#0151697)

responder: An Ask Extension Expert Replied August 22, 2024, 10:04 AM EDT
response: Good morning! Sorry for my delayed response. Thank you for sending another photo over! Do you want to bring a sample over so I can take a look at it in person? I can look under the microscope and see if we can see anything. I have time tomorrow to take a look - I will be here till 2/3 if you want to bring a sample by today or tomorrow morning! We are located at the Jefferson County Fairgrounds (15200 W 6th Ave Suite C, Golden, CO 80401) It is 20$ to drop off a sample. Your tree looks very healthy otherwise. The only thing I can think of is that there is an insect that created a puncture wound at the top of the peach and then it started to rot as it ripened.  I am in the office till noon today (8/22) and most of the day tomorrow (8/23) if you want to call for a best time for drop off!  Thanks so much, Rachel Durkan303.271.6618 <personal data hidden>

responder: The Question Asker Replied August 23, 2024, 8:10 AM EDT
response: Hi Rachel Thanks for your response.  Unfortunately, I have harvested all the plums and do not have any examples of the issue to give you.  I will have to watch for the issue next year and if it reoccurs, follow up at that time.   Thanks for your help. Patricia Dormeyer   From: ask=<personal data hidden> On Behalf Of Ask Extension Sent: Thursday, August 22, 2024 8:05 AM To: Patricia Dormeyer  Subject: Re: growth on Toka plum (#0151697)

responder: An Ask Extension Expert Replied August 23, 2024, 10:05 AM EDT
response: Ah I am sorry! Thank you so much and please feel free to bring in a sample if you see anything else! Rachel