Effect of nitrogen scheduling and weed management on weed density, growth and yield of direct-seeded rice (Oryza sativaL.)

Abstract

A field experiment was conducted during rainy (kharif) seasons of 2012 and 2013 to study the effect of nitrogen scheduling and weed management in direct-seeded rice (Oryza sativa L.) under irrigated condition. Nitrogen scheduling significantly reduced the total weed density and dry weight and increased the yield-attributing charactersand yield of crop. The results indicated that the minimum total weed density and dry weight, and maximum crop growth and yield attributing characters were recorded under four nitrogen splits: ¼ 2 WS+¼ 4 WS+¼ 6 WS+¼ 8 WS followed by 1/3 2 WS+1/3 4 WS+1/3 6 WS. Application of nitrogen scheduling at ¼ basal+¾ 4 WS and ¼ basal+½ 4 WS+¼ 6 WS recorded higher weed density and dry weightat all stages of observation during both the years. The various weed management treatments significantly decreased the density and dry weight of weed and increased the weed control efficiency, growth and yield attributing characters compared with the weedy check. Application of pendimethalin 1.0 kg/hafb bispyribac+carfentrazone (25 + 20 g)/ha and pendimethalin 1.0 kg/ha fb bispyribac+ethoxysulfuron (25+18 g)/ha recorded minimum weed density and dry weight of weed and increased the weed control efficiency, growth and yield attributing characters comparable to other treatments.