Radiation Use Effiency Flashcards
1.
Definition RUE
How effectively the intercepted radiation is being used. Amount of DM produced per unit of radiation intercepted by the crop.
RUE
DM/PAR intercept. Canopy performance and light intercepted. The amount of DM accumulated is proportional to the amount of radiation intercepted.
What is the RUE of C3 plants
1.4g
How is DM effected
By the amount of time that the crop grows with an active canopy
What are C3 crops better at doing than C4
Better photosynthetic rate @lower temps.
When crops are working at max capacity what is the RUE
1.4 MJ of light intercepted.
What causes the differences seen in RUE
The type of product the crop is producing because lipids and proteins have a higher energy cost than carbs.
What does the amount of radiation intercepted show
How the changes in solar radiation dictates DM yield.
Describe the logestic curve
DM accumulation over time, slow DM increase, exponential phase LAI (crop working at full capacity), DM rate declines = little change in DM produced
Respiration
Drives plant growth. Used to convert stored energy to usable energy for cells. Is constant. Driven by temp ie. low in winter
Fast growing crop?
Has high assimilation & high respiration.
Nitrogen
Is a protein, what the grain is storing
What does N do?
Drives cell division, growing leaf and number of grains per head. N helps longevity of individual leaves by preventing yellowing and loss of chlorophyll required in photosynthesis.
What does chlorphyll do
Absorb light energy in photosynthesis
How much more do fertlised crops intercept of light
17%
