Which one of the following is linked to the discovery of bordeaux mixture as a popular fungicide?

Bordeaux mixture was discovered by Millardet in France in 1882. It is prepared by dissolving 40 g of copper sulphate and 40 g of calcium hydroxide in 5 L of water. It was first used to control downy mildew disease of grape-vine that is caused by a fungus Plasmopara viticola. Black rust of wheat is caused by Puccinia graminis tritici. The use of fungicide dithane Z-78 and dithane M-45 control the disease even at lower concentration. Loose smut of wheat is caused by Ustilago tritici. The use of fungicides (systemic fungicide like D-785 and F-461) give quite encouraging result.