Hello Kathryn, 

Thanks for reaching out! This UMN Extension article has some great tips on managing brown rot (scroll down to "How to manage brown rot" section): https://extension.umn.edu/plant-diseases/brown-rot-stone-fruit

Make sure to keep your tree, and the surrounding area, clean. Pick up any fruit that falls during the summer, and harvest all fruit in the fall. Pruning is recommended for any diseased wood (as you have done in the past. If keeping your orchard clean and pruning out the diseased wood does not help in the following years, fungicides may be useful. The article lists ones to try -- remember if you use a chemical, always follow the label instructions attached to the container you are using. The label is the law. 

I hope this helps!