ECONOMIC WEED MANAGEMENT OPTIONS IN WINTER RICE

Due to labor shortage chemical weed control becomes a priority by time. An experiment was carried out to find out an effective and economic herbicide to control weeds in the Agronomy Farm of Bangladesh Rice Research Institute, Gazipur, during December 2008 to June 2009 in winter season. Surjamoni and BRRI dhan-29 were used as rice cultivars. Weed control treatments were assigned using three rates of Becolor 5G (butachlor), Bouncer 10WP (pyrazosulfuron ethyl) and Becofit 500EC (Pretilachlor). Visual observation indicates that these herbicides were not toxic to rice plants. Paspalum distichum was the dominating weed species in the experimental site. Weed control efficiency ranged (WCE) from 42 to 84%. Above 80% WCE was obtained by Becolor 5G @ 30 kg ha-1 , Bouncer 10WP @ 150g ha-1 and Becofit 500EC @ 1.20 L ha-1 , respectively. The highest grain yield (6.96 t ha-1) was obtained from Surjamoni when treated with Bouncer 10WP @ 150g ha-1 which was 49% higher than control. BRRI dhan29 produced also the highest grain yield when treated with same treatment which was 37% higher than control. In terms of profitability of rice production, application of Bouncer 10WP @ 150g ha-1 gave highest gross return and gross margin than other weed control treatments. The highest (2.77) benefit cost ratio (BCR) of Bouncer 10WP @ 150g ha-1 suggested that it could be an alternative weed control option for profitable rice production.