A COMPARATIVE ANALYSIS ON PERFORMANCE OF HYBRID AND INBRED RICE IN BORO SEASON

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.