The cuttings root very easily but this is a hybrid poplar- not the common yellow poplar. Don't know if the later will root. The two younger trees in the attached pic were started as branches with the bottom 6" stuck in a hole in the ground. No rooting hormone was used.
FWIW, I've tried making arrows out of branches but they break too easily when trying to straighten them where side branches, and sometimes just leaves grew. The pipe is to prevent leaves and branches from growing and, hopefully, make for straight shaft material.