[en] Some approximate solutions of the Low equations for pi-nucleon scattering, pi-nuclear scattering and the pp → dπ⁺ reaction are discussed. Results differ from those of other treatments by the inclusion of propagator modifications which act as cutoffs for terms involving pions of relatively small momenta. Because of these propagator modifications the use of a pi-nucleon T-matrix of long range is perfectly consistent with the idea that the fundamental pi-nucleon form factor is of very short range. The origin of these propagator modifications is shown to be a proper evaluation of the energy dependence of the off-shell pi-nucleon scattering amplitude. As a consequence of the theory, good agreement with pp → dπ⁺ data is obtained without the inclusion of large effects from rho-meson exchange terms. 22 references