removal of shoot tips results in growth of lateral buds. why?

Generally shoot tip of a plant carries an apical bud that produces a hormone called auxin. This hormone inhibits the growth of the lateral buds further down the stem. This phenomenon is usually known as apical dominance. It has been observed that if the shoot tip along with the apical bud sir moved from the plant, the release of auxin hormone reduces. This low concentration of auxin allows the lateral buds to grow and produce new shoots.