Apple Tree spraying/maintenance
Ok. Apple tree newbie here. I bought 3 potted apple trees from Home Depot last year and planted them around June..... Yellow Delicious, Granny Smith, and Jonathan. The Jonathan actually produced 1 very small apple. Other than putting some composted manure around each tree I haven't done much of anything. All 3 trees are starting to bloom quite nicely this year since we've had a warmer than usual Spring so far.
My plan is to spray Sevin liquid about a month or so after petal fall and then every 3 weeks or so after that. Making sure I quit spraying within 30-40 days of harvest. Then start with the dormant spray and pruning after that.
Is this the right approach? Spray Sevin on a regular basis and Dormant Oil on a regular routine and then approach other options if I run into problems like diseases?
I'm a little confused about the spraying aspect of fruit growing. Spray only when you find a problem or spray regularly??