Effect of Different Levels of Nano Urea on Growth and Yield of Maize (Zea mays L.)

A field experiment was conducted during the kharif season of 2023 at the Zonal Agricultural Research Station, V.C. Farm, Mandya, to investigates the effects of nano urea and conventional urea doses through foliar spraying at different growth stages of the maize crop by establishing a comparative analysis between both treatments. The experiment was followed a Randomized Complete Block Design with ten treatments, replicated thrice. The treatments consisted of 75% and 100% of the recommended nitrogen dose (RDN), supplemented with foliar applications of nano urea (2, 4, and 6 ml l⁻¹) and urea (2%) at 25 and 50 days after sowing. These were compared with the recommended dose of fertilizer (RDF) alone and a control (RDF without nitrogen). The results revealed that the highest plant height (220.33 cm), SPAD readings (48.97 at 90 DAS and 35.97 at harvest), and total dry weight of leaf (55.86 g plant⁻¹) and stem (160.73 g plant⁻¹) were recorded with 100% RDN + nano urea @ 4 ml l⁻¹ foliar spray. This treatment was statistically on par with 75% RDN + nano urea @ 4 ml l⁻¹. Similarly, the highest grain yield (9256 kg ha⁻¹) and stover yield (11474 kg ha⁻¹) were obtained under 100% RDN + nano urea @ 4 ml l⁻¹, with comparable results in the 75% RDN + nano urea @ 4 ml l⁻¹ treatment. These findings suggest that nano urea application allows a reduction in nitrogen fertilizer use without compromising maize productivity, offering a sustainable alternative for nutrient management.