Vol. 12, Issue 5 (2023)

Author(s):
B Rama Devi and D Rakshith Roshan

Abstract:
A study was carried out during Kharif 2015 and 2016 to evaluate the effect of four nitrogen and six weed management practices on drymatter and nutrient removal by weed in direct seeded rice on a sandy loam soil at the Research Farm of Institute of Agricultural Sciences, Banaras Hindu University, Varanasi. The experiment was laid out in split plot design with 3 replications. The results revealed that Nitrogen significantly affect the growth characters of rice crop viz. plant height, number of tillers m ^-1 row length, dry matter accumulation /25cm row length with the application of ¼ N at basal + ¼ at active tillering stage + ¼ N at panicle initiation stage +¼ at heading stage and was found at par with 1/3 N at basal + 1/3 N at active tillering stage + 1/3 N at panicle initiation stage than other nitrogen treatments during both years of experimentation. Among weed management practices, application of bispyribac at 25 g a.i. ha^-1 + azimsulfuron at 17.5 g a.i. ha^-1 + NIS (0.25%) at 15-20 DAS recorded maximum growth attributes during both the years of study and it was at par with hand weeding twice at 20 and 40 DAS. The highest grain yield of 4560.00 and 4210.25 Kg ha^-1 were recorded under bispyribac at 25 g a.i. ha^-1 + azimsulfuron at 17.5 g a.i. ha^-1 + NIS (0.25%) at 15-20 DAS and was at par with two hand weedings at 20 and 40 DAS (4776.75 and 4380.50 Kg ha^-1) during 2015 and 2016, respectively. Whereas, application of oxadiargyl at 90 g a.i. ha^-1 (PE) fb bispyribac at 25g a.i. ha^-1 + NIS (0.25%) at 15-20 DAS was least effective and recorded minimum yield. Whereas, harvest index was not significantly influenced by nitrogen and weed management treatments.