Wow, 20 percent nitrogen is high. I would think you may have burned them. Why are you spraying so much? They arent fruit bearing age and i wouldnt think that tou would need to spray that much.
Sounds like a salesman that makes commission on spray.
I cant speak for most folks, but even here in the northeast, which is notorious for fungal and bacterial apple diseases, many folks don’t spray weekly. I cant think of a single one actually
I don’t have any experience with Neem Oil but isn’t it true that you should not spray oil and sulphur too close together? I generally only spray dormant oil as a smothering oil during dormancy, and only use sulphur during the powdery mildew season in the middle of summer, so I haven’t dealt with this. (In arid Montana you can get away with that!)