EFFECT OF TRANSPLANTING DATES ON THE GROWTH AND YIELD OF HYBRID RICE (Oryza saliva L.) VARIETIES IN AUS SEASON

Abstract

A field experiment was conducted at the Agricultural Botany Experimental field of Sher-e-Bangla Agricultural University (SAU), Dhaka during Aus season in March to July 2010, with a view to study the effect of transplanting dates on the growth and yield of hybrid rice varieties along with one modem variety. The experiment consisted of two levels of treatments viz. A: Three varieties where two of them were hybrids and one was inbred: Fleera2, Aloron (Hybrid) and BRRI dhan48 (Inbred). B: Four transplanting dates: 16°' March. 31 March, 150' April and 301h April. The experiment was laid out in randomized complete block design with three a   replications./perimental results showed that transplanting dates and varieties individually had significant effect on the growth and yield parameters like plant height, number of total tiller hill, leaf area hilF1 . total dry weight (g hilt'), light interception percent, chlorophyll content at flag leaf stage, number of effective tiller hilt', panicle length, number of filled spikelet panicle', number of unfilled spikelet panicle1, number of total spikelet panicle', spikelet filling percent, grain yield (t hi 5. straw yield (t ha'), biological yield (t ha') and harvest index (%)fFhe results revealed that 16° March transplanting gave the highest grain yield (3.82 t ha Chlorophyll content Was higher in Heera2 followed by, Aloron. In contrast chlorophyll content was lower in BRRI dhan48. Among the varieties BRRI dhan48 gave the highest grain yield (3.5 It ha1) but both the hybrid varieties Heera2 (3.03 t ha') and Aloron (2.77 t ha4) gave lower grain yield due to higher spikelet sterility because of more sensitiveness of hybrid rice varieties to high temperaPire and low sunshine hour at grain filling stage. The combined effect of transplanting dates and variety had also significant effect on yield and yield contributing characters. BRRI dhan48 transplanting on 161' March showed highest grain yield attaining good yield contributing characters.