The Trojan Horse Method is a powerful indirect technique allowing one to measure the bare nucleus S(E)-factor and the electron screening potential for astrophysically relevant reactions without the needs of extrapolations. The case of the (p,alpha) reactions induced on the two boron isotopes B-10,B-11 is here discussed in view of the recent Trojan Horse (TH) applications to the quasi-free B-10,B-11+H-2 reactions. The comparison between the TH and the low-energy direct data allowed us to determine the electron screening potential for the B-11(p,alpha) reaction, while preliminary results on the B-10(p,alpha) reaction have been extracted.