GROWTH AND YIELD OF HYBRID AND INBRED BORO RICE AFFECTED BY DIFFERENT METHODS OF WEED CONTROL

A field experiment was carried out at Sher-e-Bangla Agricultural University, Dhaka, Bangladesh during the period from December, 2008 to May, 2009 to evaluate the growth and yield of hybrid and inbred boro rice as affected by different weed control methods. The experiment comprised of seven weeding treatments and three varieties of boro rice. The experiment was carried out in RCBD with threereplications. Eight weed species belonging to four families were identified in the experimental field. Densities of weeds were recorded from 7 DAT to 50 DAT at 7 days interval. It was found that among the weed control treatments, application of Sunrice 150WP (ethoxysulfuron) 125 g a.i. ha-1 showed best performance in respect of the highest plant height (103.35cm), maximum tillers hill-1 (22.00), themaximum plant dry matter (192.8g hill-1), effective tillers hill-1 (20.34), lowest number of ineffective tillers hill-1 (1.33) and consequently produced highest grain yield (9.50 t ha-1), straw yield (10.25 t ha-1) and harvest index (41.16) in comparison to all other treatments. Among the weed control treatments-Sunrice 150WP (ethoxysulfuron) 125 g a.i. ha-1 controlled 81% weed population, whereas Commit 500EC pretidachlor gave 62% and hand weeding only 52% control. The highest grain yield, straw yield as well as benefit cost ratio was obtained from the variety Sonarbangla hybrid dhan 6. under Sunrice 150 WP (ethoxysulfuron) 125 g a.i. ha-1 which increased 22.58% grain yield than Commit 500EC(pretidachlor) 750 ml ha-1 and 34.58% grain yield than two hand weedings, due to higher number of panicles hill-1 and number grains panicle-1.