Lecture 8: Biotic Interactions

Question 1

Biotic interactions

Answer 1

Result in significant reductions in the yield of crops

Question 2

Examples of biotic interactions processes

Answer 2

Disease: plants pathogens

herbivory: pests = herbivores
competition: weeds and neighbouring plants

Question 3

Disease

Answer 3

Damage to plants due to infection by plant pathogenic microorganisms.

Question 4

Disease

3

Answer 4

Viruses
Bacteria
Fungi

Question 5

Example of viruses in plants

Answer 5

Cucumber mosaic

Question 6

Example of bacteria affecting plants

2

Answer 6

Crown gall, soft rots

Question 7

Examples of fungi affecting plants

3

Answer 7

Potato blight
Dutch elm disease
Ash dieback

Question 8

How do competition, pathogens and pests affect plant growth?

Answer 8

By interfering with host plants ability to acquire and utilise essential resources such as, light, water, CO2 and nutrients.

Question 9

Plamt growth and crop yield are often direct linear functions of …

Answer 9

Cumulative light interception

Question 10

Light interception depends on leaf area

2

Answer 10

Amount of light area

Position of the leaves

Question 11

The plant that intercepts the most light competes…

Answer 11

Most strongly

Question 12

Plant adaptations conferring strong competitce ability

3

Answer 12

Taller plants
Bigger plants
Faster growing plants

Question 13

Three ways pests and pathogens can reduce yield by?

Answer 13

1. Reducing light interception (leaf area)
2. reducing the effiency with which light is utilised (photosynthesis)
3. Combination of 1&2