This Clemson article is handy as it has a list of all the chemicals you might find at Lowes or your local garden center under various brand names. Some of the commercial chemicals are available for home use although the active ingredients are at a lower percentage if you read the labels.
Similar fact sheets for other plants such as powdery mildew on your ornamentals are also available on that site.
I posted this on a thread yesterday. Seems like most comprehensive document on managing fruit tree diseases. Includes both synthetic and biological control approaches.
UC_Comprehensive_disease_management_fruit_trees.pdf (2.1 MB)
I like the article. I wish some of these publications would include photos of the diseases or conditions they are talking about. Photos really help so you know what they are talking about and not have to keep going to different sites to get that info or photos.