Bioassay for Herbicide Residues Applied to Control Weeds in Grassland

Abstract

A laboratory experiment was conducted during Kharif 2021 at Department of Agronomy, College of Agriculture, CSK Himachal Pradesh Krishi Vishvavidyalaya, Palampur, to study the residue of flumioxazin herbicide in soil taken from field with treated flumioxazin through bioassay. Nine weed control treatments including flumioxazin 150 g/ha, 200 g/ha, 250 g/ha, 300 g/ha, 500 g/ha, oxyfluorfen 1000 g/ha, weed free check, glyphosate 4000 g/ha and untreated control were evaluated in completely randomized block design with three replications in field experiment. Rice, maize, wheat, oats, mustard and cucumber were used as indicator plant in bioassay to test the residual effect of flumioxazin in the soil of treated plots. Two growth parameters i.e. shoot length and root length were measured for all plant species. Soil samples were collected at 30 and 60 days after spray and analyzed for residue using bioassay. The results revealed that shoot length and root length of all the six indicator plants were not significantly affected by residue of various herbicides during the period of investigation. Therefore all the six indicator crops viz. wheat, maize, rice, oats, mustard and cucumber successfully be grown under field condition after the application of this herbicide.