Physiology of Yield

Question 1

What percentage of global food production is animal product and plant product?

Answer 1

18% animal product
82% plant product

Question 2

How much protein is from animal products and plant products?

Answer 2

32% animal products
68% plant products

Question 3

How can yield be improved?

Answer 3

• More energy in (increased nutrients, increased efficiency of lighter interception, increased photosynthetic efficiency.)
• More energy into yield

Question 4

What is the most variable factor for plants and why?

Answer 4

Light environment
Different angles of light throughout the day and year.

Question 5

What factors affect light interception?

Answer 5

• Leaf morphology
• Leaf area index
• Leaf movement
• Plant structure
• Canopy structure
• Leaf angle
• leaf duration

Question 6

Explain how leaf morphology affects light interception.

Answer 6

Absorption changes through the leaf.
Blue and red light absorbed in upper layer of leaf.
Green light travels further in leaf, less well absorbed.
Far red light travels the furthest.

Question 7

Explain how leaf area index (LAI) affects light interception.

Answer 7

LAI = the total of leaf area per unit of ground.
LAI determines light interception, photosynthesis and evapotranspiration.

Question 8

What are the 3 types of leaf angle and give examples.

Answer 8

Erectophile: >30 degrees. e.g. wheat, rice, maize
Plagiophile: 30-60 degrees. e.g. sugar beat, tobacco, rapeseed
Plantophile: <60 degrees. e.g. cucumber, clover, soybean

Question 9

Explain how leaf duration affects light interception.

Answer 9

The longer a leaf persists, the more it can photosynthesise.
Many crops are bred to favour early leafing and late senescence.
Early flowering and late senescence = increase in grain weight.