[en] The present work is based on neutrino experiment data with the Gargamelle bubble chamber in the broad band beam of the CERN protonsynchrotron. For the first time the reaction νn → νn π⁰ was separated from the π⁰-production at the proton. Besides, the reactions ν¹H → μ^-pπ⁺ could be separated at the free proton by means of kinematic techniques. However, about 80% of all reactions take place at the bound nucleons and this way the observed final state can be falsified by intranuclear secondary interactions. A correction of this falsification was made by means of a model calculation. By using recent nuclear physics data the model parameter could be calibrated and the correctness of the model calculation could be proved in all details. As a result the cross sections for the 1π-production could be given for free nucleons. The behaviour of these cross-sections was investigated in dependence of the invariant mass of the hadronic final state to find some clues of the isospinstructure of the weak currents. (orig./HSI)