Q.What is sprayed for Bitter Pit? Is it sprayed on the apples? When should it be sprayed?
The Bitter Pit article mentioned spraying for the disorder, but it did not include any details, Where can I learn more about this problem?

Certified GKH Gardening Expert
Here's an extension service article that will give you a little more detailed info:
https://extension.psu.edu/apple-fruit-disorders-calcium-deficiency.
Here is a link for your local extension service:
https://www.gardeningknowhow.com/extension-search?zip=98204&radius=50&services_search_action=search&submit=Search