Effect of foliar application of antitranspirants and micronutrients on the yield and water productivity of Rice (Oryza sativa L.) under regulated deficit irrigation

Abstract

Rice (Oryza sativa L.) production is increasingly constrained by water scarcity, necessitating efficient water management strategies. A field experiment was conducted during kharif 2024 at Lovely Professional University, Punjab, to evaluate the combined effect of regulated deficit irrigation (RDI) and foliar application of anti-transpirants and micronutrients on rice yield and water productivity. The experiment was laid out in a split-plot design with three replications, comprising three irrigation regimes in main plots-I₁ (deficit at panicle initiation), I₂ (deficit at flowering), and I₃ (no deficit)—and four foliar treatments in subplots- T1 (control), T2 (selenium 20 mg L⁻¹ + silicon 1.5 mM), T3 (kaolin 6%), and T4 (salicylic acid 10⁻³ M). Among irrigation treatments, I₃ recorded the highest grain yield (5077.85 kg ha⁻¹), straw yield (12786.67 kg ha⁻¹), chlorophyll content (1.789 mg g⁻¹), and water use efficiency (5.196 kg ha⁻¹ mm⁻¹), while I₂ resulted in the lowest grain yield (2905.56 kg ha⁻¹) and WUE (2.973 kg ha⁻¹ mm⁻¹). Among foliar treatments, T4 produced the highest grain yield (4699.77 kg ha⁻¹), grains per panicle (130.55), 1000-seed weight (22.59 g), chlorophyll content (1.823 mg g⁻¹), and WUE (4.809 kg ha⁻¹ mm⁻¹), whereas T₀ gave the lowest grain yield (3601.44 kg ha⁻¹). Numerically, I3 with salicylic acid had the highest yield; however, the irrigation × treatment interaction for grain yield was not significant, so inference is based on main effects. The study demonstrates that foliar application of kaolin and salicylic acid can partially alleviate the adverse effects of water deficit and improve water productivity in rice cultivation.