Determination of Critical Period for Sustainable Weed Management and Yield of Jute (Corchorus olitorius L.) under Sub-Tropical Condition

A field investigation was run to ascertain the critical period of weed control in jute (Corchorus olitorius). The study consisted of two distinct sets of treatments, with one set of weeds being left to invade the crop for a longer period of time, specifically, for 15, 30, 45 and 60 days after sowing (DAS) and up to harvest. In the other set of treatments, the plants remained weed-free for progressively longer periods, i.e., 15, 30, 45 and 60 DAS, and until harvest. The reduction in fibre yield (FY) was recorded as 53.39% when weed interference was permitted from the beginning to harvest, as opposed to the season-long weed-free period. The critical period for weed competition (CPWC) of jute was calculated as being 11 to 68 DAS and 19 to 59 DAS, based on results of 5% and 10% yield loss, respectively. Under the 5% yield loss condition, although yield was higher (3.36 t ha(-1)), the benefit cost ratio (BCR) was lower (1.65), whereas yield was slightly lower (3.19 t ha(-1)) but BCR was higher (1.73) with respect to 10% yield loss. Therefore, jute fields should be kept weed free from 19 to 59 days after sowing, and a weed management strategy should be undertaken accordingly.