4-(HALLO -BRANCHED ALKYL, CYCLOALKYL OR SILYL) PYRIDAZIES, PROCESS FOR THEIR PREP ARATION AND FUNTANING THEM

摘要

Plants are protected from the damaging effects of Phycomycetous fungi by a series of pyridazines of formula ##STR1## wherein R.sup.3 is chloro, bromo, methyl, cyano or iodo;PP R is chloro, bromo, iodo, methyl, cyano or furan-2-ylmethoxy;P PR.sup.1 is hydrogen, methyl, ethyl or n-propyl;PPR. sup.2 is ##STR2## X is fluoro, chloro, bromo or iodo; X.sup.1 and X.sup.2 independently represent X or hydrogen, provided that no more than one of X.sup.1 and X. sup.2 is hydrogen;PPR.sup.4 is hydrogen, chloro, bromo, methyl or ethyl;PPR.sup.5 is hydrogen, chloro, methyl, ethyl, chloromethyl or dichloromethyl;PP or R.sup.4 and R. sup.5 combine with the group to which they are attached to form a C.sub.3 -C.sub.7 cycloalkyl group substituted with a R.sup.1 group;P PR.sup.6 is hydrogen, chloro, bromo, methyl or ethyl;P PR.sup.7 is hydrogen, methyl, ethyl, chloromethyl or dichloromethyl; PPone of m and n is 0 or 1, and the other is 0;P Pp is 0-4.