The Korean Journal of Crop Science ISSN:0252-9777(Print) 2287-8432(Online) 한국작물학회지

This study was conducted to evaluate the weed-control efficacy, phytotoxicity, and residue levels of two non-selective herbicides, glufosinate ammonium at 18.0% and glufosinate ammonium–tiafenacil at 16.8%, applied 15 days before flooding in transplanted rice cultivation. Field experiments were conducted in Wanju and Nonsan, Republic of Korea, to allow their effectiveness against weedy rice and annual weeds, as well as their safety when applied to rice plants and residue persistence in harvested products to be assessed. In Wanju, the control efficacies of glufosinate ammonium at 18.0% and glufosinate ammonium–tiafenacil at 16.8% against weedy rice and annual weeds were 97.9% and 98.8%, respectively. In Nonsan, the corresponding control efficacies were 98.1% and 100.0%, respectively. These results demonstrated excellent weed-control performance for both herbicides across locations. Phytotoxicity assessments revealed no visible injury symptoms in rice plants at either the recommended application rate or twice the recommended rate for both herbicides when compared with the hand-weeded control. Furthermore, residue analysis conducted after harvest demonstrated that herbicide residues in brown rice and rice straw were below the detection limit (<0.01 mg kg^-1) in all treatments. The results indicate that the application of glufosinate ammonium at 18.0% and glufosinate ammonium–tiafenacil at 16.8% 15 days before flooding provides effective control of weedy rice and annual weeds without exerting phytotoxic effects on rice plants or leaving detectable residues in harvested products. Therefore, these herbicides can be safely utilized as an effective pre-flood weed-management strategy in transplanted rice cultivation.