What can I do to prevent my espalier apple tree fruit from getting sun-scorched?

Hi Doreen, there are several things you can do to prevent sunscald on fruit. In hot weather extra watering will help; when pruning leave some leaf as cover for the fruit; avoid bare ground underneath the tree, underplant with nasturtium or other flowering herbs; encourage air circulation around the tree, heat will be bouncing off the wooden fence; use shade cloth or green mesh bags over the fruit; feed regularly with a  fertiliser that contains calcium - dolomite lime, gypsum or garden lime may be beneficial. If the fruit is nearly ready, pick it and ripen it off the tree.