Evaluation of herbicides to control alligator weed (Alternanthera philoxeroides) in mid hills of Himachal Pradesh

Abstract

An open pot experiment was conducted during Kharif 2020 and 2021 at Research Farm of Department of Agronomy, College of Agriculture CSK Himachal Pradesh Krishi Vishvavidyalaya, Palampur, H.P. to evaluate herbicides for the control of Alternanthera philoxeroides. The experiment was laid out in completely randomized design with three replications and consisted of ten herbicide treatments viz. glyphosate 1000 g/ha, paraquat 1000 g/ha, 2,4-D Na salt 1250 g/ha, 2,4-D ethyl ester 1000 g/ha, metsulfuron methyl 4 g/ha, carfentrazone 25 g/ha, glufosinate ammonium 500 g/ha, bispyribac Na 20 g/ha, flumioxazin 200 g/ha, diuron 500 g/ha and one weedy check (control). All the herbicide treatments resulted in significantly better control of Alternanthera compared to control (weedy check). Glyphosate 1000 g/ha remaining at par with metsulfuron methyl 4 g/ha provided lowest shoot count at all stages of observation during both years. This was followed by application of 2,4 D ethyl ester 1000 g/ha and carfentrazone 25 g/ha which except for initial stage of observation gave results statistically similar to glyphosate 1000 g/ha and metsulfuron methyl 4 g/ha from 25 to 55 days after 2 spray. The lowest weed dry matter (g/m ) and therefore highest weed control efficiency was recorded with application of glyphosate 1000 g/ha, metsulfuron methyl 4 g/ha and 2,4 D ethyl ester 1000 g/ha at 55 days after spray.