Fruit Tree Disease Blog
Don't know if you know about this site or not, but I just stumbled a website devoted to monitoring the disease pressure on fruit trees. The writer is a fruit tree disease pathologist from the Virgina Tech research station in Winchester, VA (Northern VA) so it's based on those weather conditions. But there's still a ton of interesing information there for where ever you are.
The link for the website/blog is included below.
Here's the link for the spray guide:
Here is a link that might be useful: fruit tree disease blog