Question

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

• A. Bacterial leaf blight of rice
• B. Downy mildew of grapes
• C. Loose smut of wheat
• D. Black rust of wheat

Answer 1

Answer: (B)

Bordeaux mixture was discovered by Millardet in France in $1882.$ It is prepared by dissolving $40g$ of copper sulphate and $40g$ of calcium hydroxide in $5L$ 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 $D-735$ and $F-461$ ) give quite encouraging result.