Influence of nitrogen levels and weed management treatments on weed growth and yield of direct seeded rice (DSR) in the central plains of Punjab

Rice (Oryza sativa L.) is the most important staple food of the Indian population. The huge infestation of both paddy and non-paddy weeds in direct-seeded rice and poor knowledge of weed management results in low yields in DSR. This was the major drawback resulting in farmers' poor adoption of this technology, as uncontrolled weeds lead to more than 95 % crop yield losses. Considering the facts as mentioned above, The present study was conducted at Lovely Professional University, Phagwara, Punjab (India). The field trials were designed in the Split Plot Design during 2022 and 2023. Different nitrogen levels viz., 0 kg/ ha, 120 kg/ha, 150 kg/ha and 175 kg/ ha were included in the main plots and four weed management treatments in the subplots viz., pendimethalin followed by bispyribac, brown manuring with pre-emergence. The experiment included the application of pendimethalin followed by bispyribac, brown manuring followed by bispyribac and unweeded (control)". Among the nitrogen levels, maximum paddy yield was observed at 175 kg N/ha, which was found to be at par with 150 kg N/ha. Both these treatments were superior to 125 kg N/ha and 0 kg N/ha. Among weed management treatments, pre-emergence application of pendimethalin followed by post-em. bispyribac recorded significantly higher yield than all other weed management treatments. The higher yield in pre-emergence pendimethalin followed by post-emergence bispyribac treatment may be due to better control of paddy and non-paddy weeds. Also, application of preemergence pendimethalin followed by bispyribac in the brown manuring treatment significantly increased paddy yield compared to its no application of pendimethalin.