My next step was to choose a single shoot growing from the scion and train that shoot to a bamboo stake. In the photo series above, you can see that the scion sprouted three, equally-vigorous shoots. I pruned out the lower two shoots and kept the shoot growing from the top of the scion. I made this choice based on the direction this upper shoot was growing--right in line with my bamboo stake. I then used some flagging tape to tie the remaining shoot to the stake to prevent wind damage to the tender shoot.
The red arrow in the photo above points to an upward growing limb. I removed this limb by pruning back to the point it connected to a major lateral limb. The photo above-right shows the tree after pruning.
The photo below shows my tree after pruning and training. You should note that the new graft is fully exposed to sunlight and remains in the central leader position. I'll need to revisit this tree in a few weeks to prune where necessary and to keep the rapidly growing graft tied to the stake.