Agriculture Reference
In-Depth Information
A
B
40
40
T
upper
30
30
20
20
10
10
T
base
T
base
0
-10
0
-10
0
10
20
30
40
50
0
10
20
30
40
50
Temperature (°C)
Temperature (°C)
Thermal Time = Temperature - Tbase, TT ≥ 0
T
opt
T
optl
T
optu
C
D
1.0
1.0
0.8
0.8
0.6
0.6
0.4
0.4
0.2
0.2
T
base
T
max
T
base
T
max
0.0
0.0
-10
0
10
20
30
40
50
-10
0
10
20
30
40
50
Temperature (°C)
Temperature (°C)
Thermal Time = DR × (Temperature - Tbase), TT ≥ 0
Fig. 2.3
Development rate as a function of temperature. Examples of different approaches for estimating thermal time are
shown in each graph. Curvilinear temperature response function shown in parts c and d are based on Friend et al. (1962),
Cao and Moss (1989), and Jame et al. (1998).
T
base
is the base temperature (i.e., development rate is zero),
T
opt
is the optimum
temperature (i.e., development rate is at the maximum),
T
optl
and
T
optu
are the lower and upper temperatures for the optimum
temperature range, and
T
max
is the maximum temperature (i.e., development rate is zero).