A powderous formulation comprising (i) 0.5 to 60 wt-%, based on the total weight of the powderous formulation, of at least one compound of formula wherein X is -N- or -CH- and R 1 is H or a C 1 -C 4 alkyl moiety, and (ii) 0.5 - 50 wt-%, based on the total weight of the powderous formulation, of at least one auxiliary compound selected from the group consisting of aluminum ammonium sulphate, aluminum potassium sulfate, ammonium acetate, ammonium bisulphite, ammonium carbonate, ammonium chloride, ammonium dihydrogen phosphate, ammonium hydrogen carbonate, bentonite, montmorillonite, calcium aluminates, calcium carbonate, calcium silicate, synthetic calcium sulphate dihydrate, calcium sulfate, kaolinitic clays (such as Kaolin), diatomaceous earth, perlite, potassium bisulphite, potassium hydrogen carbonate, potassium sulphate, potassium carbonate, sepiolitic clays, silicic acid, synthetic sodium aluminosilicate, sodium aluminosulfate, sodium bisulphate, sodium carbonate, sodium chloride, sodium hydrogen carbonate, sodium sulphate, vermiculite, calcium carbonate, magnesium carbonate, calcareous marine algae, magnesium oxide, magnesium sulphate, dicalcium phosphate, tri-calcium phosphate, mono-dicalcium phosphate, defluorinated rock-phosphate, monocalcium phosphate, calcium-magnesium phosphate, mono-ammonium phosphate, magnesium phosphate, sodium-calcium-magnesium phosphate, mono-sodium phosphate, glycerol, propylene glycol (E 1520), glyceryl triacetate, sorbitol, polydextrose, lactic acid and urea, and (iii) up to 40 wt-%, based on the total weight of the powderous formulation, of a carrier material, and wherein the auxiliary compounds have an average particle size (d 0.5) of 10 μm - 100 μm. (i) 0.5 to 60 wt-%, based on the total weight of the powderous formulation, of at least one compound of formula wherein X is -N- or -CH- and R 1 is H or a C 1 -C 4 alkyl moiety, and (ii) 0.5 - 50 wt-%, based on the total weight of the powderous formulation, of at least one auxiliary compound selected from the group consisting of aluminum ammonium sulphate, aluminum potassium sulfate, ammonium acetate, ammonium bisulphite, ammonium carbonate, ammonium chloride, ammonium dihydrogen phosphate, ammonium hydrogen carbonate, bentonite, montmorillonite, calcium aluminates, calcium carbonate, calcium silicate, synthetic calcium sulphate dihydrate, calcium sulfate, kaolinitic clays (such as Kaolin), diatomaceous earth, perlite, potassium bisulphite, potassium hydrogen carbonate, potassium sulphate, potassium carbonate, sepiolitic clays, silicic acid, synthetic sodium aluminosilicate, sodium aluminosulfate, sodium bisulphate, sodium carbonate, sodium chloride, sodium hydrogen carbonate, sodium sulphate, vermiculite, calcium carbonate, magnesium carbonate, calcareous marine algae, magnesium oxide, magnesium sulphate, dicalcium phosphate, tri-calcium phosphate, mono-dicalcium phosphate, defluorinated rock-phosphate, monocalcium phosphate, calcium-magnesium phosphate, mono-ammonium phosphate, magnesium phosphate, sodium-calcium-magnesium phosphate, mono-sodium phosphate, glycerol, propylene glycol (E 1520), glyceryl triacetate, sorbitol, polydextrose, lactic acid and urea, and (iii) up to 40 wt-%, based on the total weight of the powderous formulation, of a carrier material, and wherein the auxiliary compounds have an average particle size (d 0.5) of 10 μm - 100 μm.