Infectious diseases in plants

• Tobacco mosaic virus (TMV)

  A very widespread plant infection that affects a number of different plant species including tomatoes
• Rose black spot

  A fungal plant disease
• Causes of rose black spot

  1. Spread by water

  2. Spread by wind
• TMV symptoms

  • Causes leaves to discolour in a mosaic pattern
  • This causes reduced photsynthesis and reduced growth
• Symptoms of rose black spot

  • Leaves develop purple or black spots
  • Leaves turn yellow and fall off
  • Causes rate of photosynthesis and growth to fall
• Treating rose black spot

  • Spray plant with fungicides
  • Remove infected eaves and destroy them