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.