EFFECT OF RATOONING ON DIFFERENT VARITIES OF BORO RICE UNDER VARYING CUTTING HEIGHT

Abstract

An experiment was carried out at the Agronomy Field, Sher-e-Bangla Agricultural University. Dhaka during the period from November 2009 to July 2010 to study the effect of variety and cutting height of main crop plants on the performance of ratoon horo rice. Four cutting heights were (0.15.30 and 45 cm) and four varieties ( BRRI hybrid dhan-l. BRRI dhan28, BRRI dhan36 and BRRI dhan45) were tested. Variety had significant effect on almost all the crop characters like plant height, total number of tillers per hill, number of effective tillers per hill, number of non-effective tillers per hill, panicle length, days to panicle initiation, number of grains per panicle, number of sterile spikelets per panicle, total number of spikelets per panicle, days to maturity. 1000-grain weight. grain weight per hill, grain yield, straw yield. and harvest index in the ratoon crop. BRRI dhan28, BRRI dhan36 showed greater ratoon yields (1.8 t/ha and 1.79t/ha). Likewise cutting height also had significant effect on plant height, number of effective tillers per hill, number of non-effective tillers per hill, panicle length. days to panicle initiation, number of sterile spikelets per panicle, total number of spikelets per panicle. 1000-grain weight, grain yield, straw yield and harvest index. Cutting height Of 30 to 45 cm showed higher yields (1.7-1.69 tlha).Grain yield was highest at 30 cm cutting height of BRRI dhan28 and the second highest grain yield were at 30 cm cutting height of BRRI dhan36. All of the crop characters in the ratoon crop were significantly affected by the interaction of variety and cutting height of main crop.