I re-read the excellent Ecological Fruit Production in the North this summer. Since it is out of print, I will pass on some information of interest.
Pears need high phosphorus longer than apples (10-12 years) and only half as much nitrogen.
For established apple trees apply 25-50 kg (55-110 lbs) of compost per tree in spring. At the end of July apply 2 kg (4.4 lbs) of Sul-Po-Mag (or K-Mag) and 3 kg (6.6 lbs) of dolomite lime to prepare tree for winter. A similar version recommends applying yearly 5 kg (11 lbs) of compost for every year of tree age, ie. a 5 year old tree would get 25 kg (55 lbs)
In a planting hole mix 1 part compost with 2 parts soil plus: 3 cups colloidal phosphate rock, 1 cup bone meal, 1 cup dolomite lime, 1 cup Sul-Po-Mag (K-Mag), and 1 cup seaweed meal.
Some personal remarks follow:
With cool, cloudy summer and extra August rain, the ripening time is later, more so for my pie cherries and plums than the apples. Besides ripening later, my apples were smaller, had less color, were juicier (though probably less sweet), and seemed to drop more readily. My Yellow Jay apple as of 9/21 hasn’t fallen nor have seeds fully browned, but the flesh has browned as if it were over-ripe from long storage, yet the fruit is still crisp and juicy. It’s as if it got over-ripe before it got ripe. It must be some strange symptom of so much rain.