New substituted pyridine-4-carboxamides of the formula ##STR1## in which R.sup.1, R.sup.2, R.sup.3, X.sup.1 and X.sup.2 have the meanings given in the description, a plurality of processes for the preparation of these substances, and their use for generating resistance in plants against attack by undesired microorganisms.

Novel pyridyloxy-acrylic acid esters of the formula ##STR1## in which Ar represents optionally substituted aryl or represents optionally substituted heteroaryl, a process for preparing the novel compounds and their use as agents for combating pests. Novel intermediates, processes for their preparation and their use for the synthesis of pyridyloxy-acrylic acid esters.