Response of Crop Water Requirement and Yield of Irrigated Rice to Elevated Temperature in Bangladesh
Table 4
Genetic coefficient calibration of BRRI dhan28 for Bangladesh condition.
Parameter
Meaning
Default (BR14)
BRRI dhan28
P1
Time period in GDD (growing degree days) in °C above a base temperature from seedling emergence during which the rice plant is not responsive to changes in photoperiod
560
825
P2O
Critical photoperiod or the longest day length (in hours) at which the development occurs at a maximum rate
11.5
12.6
P2R
Extent to which phasic development leading to panicle initiation is delayed (expressed as GDD in °C) for each hour increase in photoperiod above P2O
200
150
P5
Time period in GDD °C from beginning of grain filling to physiological maturity
500
425
G1
Potential spikelet number coefficient as estimated from the number of spikelets per g of main culm dry weight
45
50
G2
Single grain weight () under ideal growing conditions
0.026
0.022
G3
Tillering coefficient (scalar value) relative to IR64 cultivar
