Abstract: The invention provides new solvent concentrates of the fungicidally active substance triforine (N,N'-bis[1-formamido-2,2,2-trichloroethyl]-piperazine) characterized by good solubility and good stability to cold and heat.

Abstract: The invention provides fungicidal compositions containing phosphonium salts of formula: ##STR1## in which n represents 0, 1, 2 or 3, R represents a halogen atom or an optionally substituted alkyl, haloalkyl, alkoxy or haloalkyl group, R.sup.1, R.sup.2 and R.sup.3 independently represent an optionally substituted alkyl, cycloalkyl, phenyl or benzyl group and X represents an anion; certain novel phosphonium salts, a process for the preparation of such compounds and a method of combating plant pathogenic fungi using such compositions or compounds.