Infectious Diseases in plants

Question 1

What is Tobacco Mosaic disease?

Answer 1

• Causes leaves to discolour in a mosaic pattern.
• Because of this discolouration photosynthesis is reduced.
• Growth of plant is reduced.

Question 2

What is rose black spot?

Answer 2

• Caused by a fungus.
• Causes the leave to: develop purple and black spots.
• Leaves then turn yellow and fall off.
• Causes rate of photosynthesis to fall + reduces rate of growth.
• Can be spread by wind or water.

Question 3

How do we treat rose black spot?

Answer 3

• Spray the plants with chemicals which kill fungi (fungicides).
• Remove infected leaves and destroy them.