We lovingly planted pear trees to 'mirror' a few extant pear trees from almost a century ago, when our land was a working orchard. These 'young' pear trees are healthy, look happy...but never yield fruit we can pick and eat. Midway to full growth, both fruit and leaves develop black spots. Almost from the first. The fruit under the black spotted skin seems fine but the pear remains underdeveloped. What could be happening? The orchard is on the Outer Cape. We're novices, obviously...please someone who knows, what could it be? Thank you.