Abstract:
An experiment was carried out at the Agronomy field. Sher-e-Bangia Agricultural University. Dhaka
during the period from July to December. 2006 to evaluate the economic cultivation of transplant arnan
rice under different weed management techniques and plant spacing. The experiment comprised six
weeding treatments viz, no weeding. two hand weeding at IS and 40 days after transplanting (DAT).
one weeding with BRRI push weeder at IS DAT + one hand weeding at 40 DAT. pre-emergence
application of M.Chlor 5G (Butachlor) at 5 DAT + one hand weeding at 40 DAT, pre-emergence
application of Oxastar 25 EC (Oxadiazon) at 5 DAT + one hand weeding at 40 DAT. pre- emergence
application of Rifit 500EC (Pretilachlor) at 5 DAT + one hand weeding at 40 DAT and three plant
spacings viz. 20cm x l Ocrn, 25cm x 15cm and 30cm x 20cm. Twelve weed species belonging to seven
families were found in the experimental field of which Sphenoc/ea zeylanica. Eclipta alba and Ludwigia
octovalvis were the most dominating weed species in transplanted aman rice. The overall performance
of use of Pretilachlor at the spacing of 25cm x 15cm was found to be the best and it produced the
highest grain yield (3.87 t ha"), highest net profit (23847.00 Tk ha") and highest BCR (1.79) that
followed by BRRI push weeder + one hand weeding at the spacing of 30cm x 20cm.
