PYRIDINE AND PYRAZINE DERIVATIVES, PREPARATION OF THESE COMPOUNDS, FUNGICIDAL AGENTS CONTAINING THESE COMPOUNDS AS ACTIVE INGREDIENTS, AND THE USE OF SUCH COMPOUNDS OR AGENTS AS FUNGICIDES IN AGRICULTURE AND IN HORTICULTURE

摘要

Pyridine and pyrazine compounds of the formula I wherein R1, R2, R3 and R4 are as hereinafter set forth and acid addition salts of these compounds, processes for their preparation, fungicidal compositions containing these compounds as the active ingredients and methods for the use of such compounds or compositions for combating fungi in agriculture and horticulture are disclosed.