INFLUENCE OF WEED INTERFERENCE PERIOD AND PLANTING SPACING ON THE WEED PRESSURE AND PERFORMANCE OF BORO RICE CV. BRRI DHAN29

Abstract

To study the influence of weed interference period and planting spacing on the weed pressure and performance of Boro rice cv. BRRI dhan29 an experiment was conducted at the Agronomy Field Laboratory, Bangladesh Agricultural University from December 2015 to May 2016. The experiment comprised six weed interference periods (viz. weed free, weed free up to 20 DAT, weed free up to 40 DAT and weed free up to 60 DAT, weed free up to 80 DAT and weedy condition) and three spacing of planting (viz.25 cm × 15 cm, 25 cm × 10cm, 25 cm × 20 cm) following randomized complete block design with three replications. The highest number of total tillers hill-1 (14.98), effective tillers hill-1 (12.98), filled grains panicle-1 (117.9), grain yield (5.40 t ha-1), straw yield (7.94 t ha-1) and biological yield (40.53 t ha-1) were found weed free up to 80 DAT. Considering cost and time consuming, best tillers hill-1 (15.88), effective tillers hill-1 (13.88), filled grains particle-1 (121.70) and grain yield (6.14 t ha-1) were found in spacing 25 cm × 15 cm with weed free up to 80 DAT. Weed density and dry weight were increased with the increasing weed interference period but rice grain yield increased gradually with the decreasing weed interference period. Weed free up to 80 DAT can be recommended from economic view point following the spacing of 25 cm × 15 cm for better weed suppression and higher yield of BRRI dhan29.