Question

Bordeaux mixture was discovered by:
A. Paul Muller
B. M. N. Saha
C. C. H. Barrat
D. P M A Millardert

Answer 1

Hint: Bordeaux mixture is a mixture which is used as fungicide that is to kill the growth of the fungus on the crops. This mixture was first discovered by the French botanist.

Complete answer:
The fungicide i.e., is Bordeaux mixture was first developed by the French botanist Pierre Marie Alexis Millardert. It was first invented in the late 19th century in the Bordeaux region of France. Bordeaux mixture is made up of two components. They are copper sulphate and calcium hydroxide. Another term used for calcium hydroxide is lime. Fungi like yeast, moulds and mushrooms are very damaging to the crops
Bordeaux mixture is sprayed on the plants like vines before the attack of fungus and thus it is used as a preventive treatment. The mode of action of the Bordeaux mixture is that the copper ions which are present in the mixture are known to inactivate the enzymes which are needed by the spores of the fungus to germinate and if the fungus infestation has taken place and the growth has been started, the use of the mixture is not of any use.
Fungi are known to destroy a potato crop causing the disease known as potato blight, can damage fruit like apple causing apple, scab or in grapes, causes sickening grape vines, and its effect is seen on the yield and quality of the fruits.
If the Bordeaux mixture is applied in larger quantities continuously for many years, the copper present in the mixture on continuous use becomes a pollutant.This copper ion acts as a harmful element to the fishes, earthworms, livestock and even humans.

So, the correct answer is (D).

Note: This is a fungicide and used to kill the fungi only and only before its germination, cannot kill any other group of organisms like bacteria or virus. It was first developed in France to prevent powdery mildew on the grape vines.