Good question. The plant does produce more potatoes from covered shoots but it also needs to feed itself in order to survive and produce those potatoes by way of its leaves, The idea is to encourage these shoots from the sides of the tower so that there is a greater surface area of foliage feeding the plant and hopefully making potatoes. The stolons which produce the potatoes should be covered with soil before they get too long and convert to the feeder shoots (shaws). If the stolons are covered as you say they produce offshoots, roots and potatoes.

We'll have to wait a few more weeks yet to see the results, but at the moment the plants are thriving with no sign of any disease, one of the other reasons for the experiment. All of our neighbours with potato beds lost their crop due to blight and yields have been very poor.

Thanks for watching and commenting.
Best Wishes, Andy.