Effect of rice residue on weed suppression and yield performance of boro rice

Abstract

The experiment was conducted at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh during the period from December 2017 through May 2018 to study the effect of rice residue on weed suppression and yield of boro rice. The experiment consisted of four different rice residue treatments such as no rice residue, 2.5, 5 and 7.5t ha-1rice residue, and five different herbicidal treatments such as no herbicide (H0), 25% of the recommended dose (RD), 50% RD, 75% RD and 100% of RD. The experiment was laid out in a randomized complete block design with three replications. Seven weed species belonging to five families infested the experimental plots. Weed density and weed dry weight were significantly affected by incorporation of rice residue and herbicidal treatment. The maximum weed growth was noticed with no rice residue incorporation and application of no herbicide. The minimum weed density and dry weight were found in incorporation of 5 t rice residue ha-1 and application of 100% of RD of herbicide treatment. Rice residue exerted significant effect on yield and yield contributing characters like plant height, number of total tillers hill-1, number of effective tillers hill-1 and grain yield. The highest grain yield (4.89 t ha-1) was recorded with the incorporation of 2.5 t ha-1 rice residue which was statistically identical with5 and 7.5 t ha-1 rice residues. The grain yield (5.70 t ha-1) produced by 75% of RD of herbicide was the highest among the other herbicidal treatments. The highest number of effective tillers hill-1 (12.80), 1000-grain weight (21.07), grain yield (5.87 t ha-1) and straw yield (7.21 t ha-1) were observed with the incorporation of 5 t rice residue ha-1 and 75% of the RD of herbicide treatment. Results of this study indicate that rice residue showed potentiality to inhibit the growth of weed and exerted significant effect on the yield of boro rice. Rice residue @ 5 t ha-1 with application of herbicide of 75% RD might be suggested to use for effective weed management and better grain yield of boro rice.