Plant Diseases

16. What is the primary mode of transmission for viral diseases in plants?

a) Soil

b) Wind

c) Water

d) Insects

17. Which of the following is a bacterial disease affecting grapes?

a) Late blight

b) Black rot

c) Citrus canker

d) Downy mildew

18. What is a common symptom of clubroot in plants?

a) Yellowing of leaves

b) Wilting

c) Swollen and distorted roots

d) Black spots on leaves

19. Which of the following is a viral disease affecting potatoes?

a) Late blight

b) Potato leafroll virus

c) Tomato mosaic virus

d) Anthracnose

20. Crown gall is a bacterial disease that affects which part of the plant?

a) Leaves

b) Stems

c) Roots

d) Fruits