Knowledgebase
Sour cherry trees #879191
Asked July 29, 2024, 9:50 AM EDT
St. Louis County Minnesota
Expert Response
https://www.starkbros.com/growing-guide/how-to-grow/fruit-trees/cherry-trees/pest-and-disease-control?srsltid=AfmBOopBbKsEQh3l0yjeYLMDt37fLm0xjUM0S70kYsQivfbJsVixjJwF
The “tiny grains” could be thrips. You could have several things going on. There could be an insect pest and bacterial rot or other infection.
https://www.farmbiosecurity.com.au/crops/fruit-nuts/fruit-nut-pests/cherry-pests/
At this stage, since you have fruit already, it will be important to discover the cause and treat for it to prevent it next year.
The plant disease clinic can identify the causative organism if you can’t find a match for what you are seeing. There is a cost to do testing. https://pdc.umn.edu/