Question

Which is linked to discovery of Bordeaux mixture as fungicide?

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

Answer 1

The correct option is A Downy mildew of grapes

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-735 and F-461) give quite encouraging result.

So the correct option is ' Downy mildew of grapes ' .