Herbicide mixture, LAI, N uptake efficiency, SPAD values

A field experiments was conducted during winter seasons of 2010-12 at Banaras Hindu University, Varanasi to study the effect of herbicides, nitrogen rates and it’s scheduling on associated weeds, crop growth and yield of wheat. Six weed species were common infesting wheat fields were Phalaris minor, Cynodon dactylon, Chenopodium album, Oxalis purpurea, Anagallis arvensis and Cyperus rotundus. Among the herbicidal treatments, post-emergence application (30 DAS) of sulfosulfuron + metsulfuron [32 g/ha] with higher rates 160 kg N/ha and time of application (50% basal + 25% CRI + 25% flowering) performed significantly with respect to reduction in density and biomass of weeds; increased the LAI and SPAD value ultimately enhanced the production of grain yield of wheat. Scheduling of nitrogen (50% basal + 25% CRI + 25% flowering) enhanced the nitrogen uptake efficiency and total nutrient uptake by crop than other scheduling of nitrogen. However, application of herbicide mixtures as a postemergence (30 DAS) with increased dose of nitrogen applied as 1/2 basal and topdressing 1/4 at CRI and 1/4 at flowering is most effective.