Weed smothering in jute (Corchorus olitorius L.) by its high density broadcast sowing

Jute being a C₃ crop, cannot compete with the C₄ weeds at its early stage and requires about 40 per cent of total cost of cultivation in weeding process alone. Scarcity of farm labours during weeding, spiraling labour cost, slow mechanization in jute and environment concern of herbicides encouraged us to smother weeds in jute field by its high density sowing. Experiments were thus conducted for three years at ICAR-CRIJAF, Barrackpore focusing smothering of composite weeds in jute field by its high density broadcast sowing (HDS, seed rate @ 6.0 kg/ha) and was compared with other weed management treatments. From the experiments it was found that fast growing dense jute canopy (200–348/m²) at 25 days after sowing with mean height of 29 cm, reduces the light penetration at its canopy base by 90–95 per cent and dominated all C₄ weeds. It reduced the grass, broadleaf, sedges weed population and weed bio mass by 70, 98.5, 64.5 and 91.65 per cent, respectively over manual weeding twice. Remaining weeds were rudimentary, incapable of producing seeds and decomposed before jute harvest. Only 6.3 to 7.64 lakhs jute/ha i.e., 16 to 23.5 per cent of total initial population could be harvested at maturity, 125 to135 DAS. This high density jute sowing eliminated weeding and thinning processes, saved 102 man days/ha over conventional manual weeding, produced 3.82 t fibre/ha and was cheaper by Rs. 25,500/ha. Weed smothering by intercropping green gram with jute (1:1) was also found economic, produced 0.5–1.0 t pulse grain/ha along with 2.72.9 t jute fibre and 1.7 to 2 t nitrogen rich (2.35%) pulse waste/ha. Pre emergence herbicides Pretilachlor 50 EC and Ipfencarbazone 22.8 per cent SC were found effective for weed control in jute. Spraying of Pretilachlor 50 EC @ 0.9 l a.i/ha on paira crop, immediately after rice harvest was found effective for weed control in piara crop. Thus, weed smothering by high density broadcast jute sowing will eliminate dependence on manual weeding, herbicides, and mechaninical weeding and make jute farming sustainable.