PERFORMANCE OF DIFFERENT HERBICIDES TO CONTROL WEED IN AROMATIC RICE

Abstract

The field experiment was conducted in the Agronomy field, Sher-e-Bangla Agricultural University (90 0 33´ E longitude and 23 0 77´ N longitude), Dhaka, Bangladesh, during July to December, 2018 with a view to find out the performance of aromatic rice as affected by different herbicidal weed control method. The experiment consisted of 2 factors, Factor A: Herbicide-4 viz., H 0 – Control (No herbicide used, no weeding), H 1 – Pyrazosulfuron ethyl 70% WG @ 15 g ha -1 , H 2 – Bensulfuron methyl 10% WP @ 50 g ha -1 and H 3 – Metsulfuron methyl 20% WP @ 20 g ha ii -1 and factor B: variety-3 viz., V 1

- BRRI dhan38, V 2 - BRRI dhan70 and V 3 - BRRI dhan80. The experiment was laid out in split plot design with three replications assigning herbicidal weed control in main plot and variety in sub plot. The results revealed that twenty-five weed species infested the total experimental field, which belongs to twelve different families. The most important weeds of the experimental plots were Cyperus michelianus, Echinochloa crussgalli, Cyperus esculentus, Sagittaria guyanensis, Alternanthera sessilis, Cyperus difformis, Sphenoclea zeylanica and Ludwigia octovalvis respectively. The result also revealed that the application of Metsulfuron methyl 20% WP @ 20 g ha ) treatment gave the lowest weed density and dry matter content of weed and highest grain yield which attributed to higher number of effective tiller hill -1 (13.54), number of filled grains panicle -1 (92.78), weight of 1000 grain (23.09 g). Considering variety, BRRI dhan70 produced highest grain yield (5.21 t ha -1 -1 (H 3 ), biological yield (10.44 t ha ) and harvest index (49.81 %) which may be due to higher effective tiller hill (13.54), number of filled grain panicle -1 (84.25), weight of 1000 grains (23.80 g) in this variety. On the other hand, interaction of H 3 V 2 (Metsulfuron methyl 20% WP @ 20 g ha with BRRI dhan70) treatment gave the highest grain yield (5.65 t ha −1 ) which may perhaps the highest number of effective tillers hill −1 (16.80), total tillers hill −1 (18.06), panicle length (34.81 cm), number of filled grains panicle −1 (98.46), weight of 1000-grains (26.97 g), biological yield (11.05 t ha −1 ) and harvest index (51.13 %) in this interaction. It may be concluded that application of Metsulfuron methyl 20% WP @ 20 g ha is an effective weed controlling herbicide for the maximum grain production of BRRI dhan70.