This section is from the book "The Gardener V1", by William Thomson. Also available from Amazon: The New Organic Grower: A Master's Manual of Tools and Techniques for the Home and Market Gardener.
The excessive vigour of your Pear-tree fully accounts for its barrenness. Root-pruning and a poorer soil are your remedies; and as the tree is rather old, we advise you to carefully lift one side, preserving the roots and removing the soil to within 2 feet of the hole, cutting all tap-roots; then cut back the large strong roots, and replant or relay them in the soil again. If the soil is deep, damp; and rich, see that it is thoroughly well-drained: the operation should be performed just as it drops its leaves. Then next year operate in the same manner on the other half of the roots. Your Fig is barren from the same cause - over-luxuriance - and it should be treated in the same way. If it has the range of a large space of ground, it will be best to concrete the bottom, and confine it to a comparatively small space by root-proof brick or stone work. A Fig growing as you describe must be in very rich soil, and nothing wili induce fruit-fulness but cutting off its supplies.