Abstract:
With a view to compare the performance of hybrid and inbred rice, a field experiment was conducted at
the research farm of Bangladesh Rice Research Institute (BRRI), Gazipur during Bora season, 2008-
2009. Two rice varieties (hybrid Heera2 and inbred BRRI dhan45) and six planting dates (30
December, 15 January, 30 January, 15 February, 0 I March and 16 March) were selected. The
experiment was laid out in split-plot design (RCBD) with four replications, placing variety at mainplot
and planting date at sub-plot. Heera2 produced tillers rapidly at vegetative phase but the tillers
retention capacity was lower at post-flowering stage compared to BRRI dhan45, regardless of
planting dates. Tillers production reduced gradually with delayed planting in both varieties. Heera2
exhibited significantly higher plant height and higher !lag leaf photosynthetic rate at flowering over
BRRI dhan45. Different planting dates did not exert considerable effect on flag leaf photosynthetic
rate at !lowering. Heera2 was out yielded BRRI dhan45 in early planting (30 December and 15
January). At delayed planting, grain filling (%) declined rapidly in Heera2 in comparison to
BRRldhan45. Grain yield decreased @ 36.55 kg ha·1day·1and 68.74 kg ha·1day·1 in Heera2 and BRRI
dhan45, respectively after 30 December planting. This result suggests that hybrid Heera2 is suitable only for
early Bora season.
