Effect of integrated weed management on weeds, yield and economics of tossa jute (Corchorus olitorius L.)

Abstract

A study was carried out during the pre-kharif season of 2018 and 2019 at Pundibari, Cooch Behar, West Bengal, to evaluate the efficacy of pre and post-emergence herbicides in tossa jute (Corchorus olitorius L.) over manual weeding. The experiment was laid out in a randomized complete-block design with 9 treatments, replicated thrice. The study results revealed that post-emergence herbicide-treated plots reduced the weed density by 7496% and weed biomass by 7293% compared to non-treated plots. Manual weeding twice-treated plots reduced the weed density by 8292%. Pre-emergence herbicides failed to prove its efficacy over the manual weeding. Plots treated with quizalofop-ethyl + ethoxysulfuron followed by manual weeding achieved higher yield (3.46 t/ ha) than manual weeding twice-treated plots (3.31 t/ha). Jute fibre yield and weed infestation showed a negative correlation. Yield reduction of 7.413.6 kg was recorded for every 1 kg increase in weed biomass, depending on time and method of the weed control. The study indicates that, ethoxysulfuron is a broad-spectrum herbicide. Combination of quizalofop-ethyl and ethoxysulfuron followed by manual weeding was found economically effective in controlling weeds as an alternative to labour consuming manual weeding.