Question

In a region of France, Downy mildew of grapes was confined to large varieties of graphs. Which of the following measure could be taken to grow grape vines in that region?
a. Use of disease resistant varieties.
b. Spray with Bordeaux mixture.
c. Use of a chemical fertilizer.
d. Spray with an insecticide.

• A. a and b
• B. b and c
• C. c and d
• D. a and d

Answer 1

Answer: (B)

b and c

Downy mildew is a highly destructive disease of grapevines in all grape-growing areas of the world where there is spring and summer rainfall at temperatures above 10ºC.

Both pre-infection and post-infection fungicides are widely used for the control of downy mildew.

There are no suitable sources of resistance in commercially acceptable varieties, so fungicides are the primary means of disease control. Bordeaux mixture is the first widely used chemical to protect plants from fungal infections.

so the use of fungicides & Bordeaux mixture could be taken as measures against Downy mildew of grapes.

So the answer is 'b and c'.