Espalier not throwing out enough side branches
Last year I planted an apple tree to grow as espalier. It threw out two side branches at the height of the first wire fine, but then just grew straight up, past the second and thrid wires speaced at 18 inches. This year it is not showing signs of putting out side shoots for the second and third wire heights. Do I need to prune the central stalk back to get the side branches at the desired heights?