ENHANCING RICE GROWTH AND YIELD THROUGH NITROGEN SOLUTION FOLIAR APPLICATION

Abstract

Nitrogen (N) is a crucial macronutrient that enhances vegetative growth, chlorophyll synthesis, and overall crop productivity. A pot culture experiment was conducted at the Agriculture Research Institute, Dera Ismail Khan, during the 2020 growing season to appraise the special effects of foliar-applied nitrogen on rice growth and rice yield. Treatments encompassed 0 (control), 1-4% urea solutions (N) applied at two different stages i.e., tillering and panicle initiation. Results showed that 3% foliar-applied nitrogen significantly enhanced plant height (105.2 ± 2.3 cm), tiller count (6.8 ± 0.4 plant⁻¹), leaf area index (4.2 ± 0.3), chlorophyll content (50.1 ± 1.6 SPAD), photosynthetic rate (18.7 ± 0.6 μmol CO₂ m⁻² s⁻¹), transpiration rate (5.2 ± 0.3 mmol H₂O m⁻² s⁻¹), stomatal conductance (0.41 ± 0.02 mol H₂O m⁻² s⁻¹), biomass accumulation (42.5 ± 2.1 g plant⁻¹), and grain yield (18.6 ± 1.2 g plant⁻¹). However, at 4% nitrogen, slight reductions were observed in some parameters, suggesting potential toxicity at higher concentrations. These findings suggest that 3% foliar-applied nitrogen is optimal for improving rice productivity under controlled conditions.