International Journal of Plant & Soil Science

Growth and productivity of aerobic rice are often constrained by severe weed competition and inefficient nitrogen utilisation. Nitrogen nutrition is a key factor influencing crop growth, canopy development and biomass production. Adequate nitrogen supply supports crop growth and can enable the crop to compete effectively with weeds for available resources such as light, nutrients and moisture. The present study was conducted to evaluate the influence of nano urea and nano urea-herbicide mixtures on growth attributes of aerobic rice (Oryza sativa L.). A field experiment was carried out at the College of Agriculture, Vellayani, Kerala, during 2023-2025 using a randomised block design with fourteen treatments. The treatments included penoxsulam + cyhalofop-butyl, bispyribac sodium, and fenoxaprop-p-ethyl + ethoxysulfuron, each combined with nano urea at different concentrations (0.2, 0.1 and 0.05%), along with herbicide-alone treatments, weed-free check, and weedy check. The results revealed that integration of nano urea with post-emergence herbicides significantly improved growth parameters of rice compared to herbicide-alone treatments and the weedy check. Higher plant height, number of tillers, leaf area and total dry matter production were recorded in treatments receiving herbicide-nano urea combinations due to effective weed suppression and enhanced nitrogen availability. Among the treatments, penoxsulam + cyhalofop-butyl combined with 0.1 per cent nano urea produced superior growth attributes and was comparable with fenoxaprop-p-ethyl + ethoxysulfuron with 0.05 per cent nano urea. The improvement in crop growth due to reduced crop-weed competition and improved nutrient use efficiency associated with better weed management. The study indicates that the integration of nano urea with post-emergence herbicides can enhance the growth performance of aerobic rice, thereby contributing to improved crop productivity.