Combined hot water extract of lentil and grass pea increase weed control efficiency and yield of boro rice

Abstract

The agriculture sector is continuously adopting environmentally friendly and sustainable methods to reduce the harmful effects of herbicides on crop production. In this context, an experiment was conducted at the Agronomy Field Laboratory (AFL), Bangladesh Agricultural University (BAU), Mymensingh, from December 2021 to May 2022, to investigate the effect of combined hot water extracts of lentil and grass peas (ELG) on weed control efficiency and yield performance of boro rice. The experiment involved four varieties of boro rice (BAU dhan3, BRRI dhan28, BRRI dhan81, and BRRI dhan96) and four treatments of crop residues. For most weed species, varieties and crop residue extracts significantly impacted weed population (WP) and weed dry weight (DW). The highest numbers of effective tillers (NET) hill-1, numbers of spikelets panicle-1 (NSP), 1000-grain weight (TGW), grain yield (GY), and straw yield (SY) were observed in the three-times hand weeding treatment. This was followed by the combination of hot water ELG applied as a pre-emergence treatment three days after transplanting and post-emergence ten days after transplanting, with the lowest values found in the no-extract treatment. Considering interaction effects, the highest GY (7.07 t ha-1) and SY (8.23 t ha-1) were observed with hand weeding combined with the variety BAU dhan3. The results of this study indicated that hand weeding, followed by the combined application ELG crop residue, showed potential activity to suppress WP and significantly affected the yield of boro rice.