Growth, yield and yield attributes of sweet corn as affected by plant density and nano-urea based nitrogen management

A field experiment was conducted during the summer seasons of 2024 and 2025 at the Agronomy Research Farm, Narain (PG) College, Shikohabad (Firozabad), Uttar Pradesh, to study the effect of plant density and nano-urea–based nitrogen management on growth, yield attributes and productivity of sweet corn (Zea mays L. saccharata). The experiment was laid out in a split-plot design with three plant spacings (60 × 20 cm, 50 × 20 cm and 45 × 20 cm) as main-plot treatments and six nitrogen management practices as sub-plot treatments, including prilled urea alone and its combinations with foliar application of nano-urea and prilled urea spray. Results revealed that closer spacing (45 × 20 cm) produced significantly higher plant height, leaf area index, green cob yield and green fodder yield, whereas wider spacing (60 × 20 cm) recorded higher dry matter accumulation per plant and superior yield attributes such as cob length, cob weight, number of grains per cob and 100-grain weight. Among nitrogen management practices, application of 75% nitrogen through prilled urea supplemented with two foliar sprays of nano-urea (4 ml L⁻¹) at 25 and 50 DAS resulted in significantly higher growth parameters, yield attributes, green cob yield and green fodder yield compared to other treatments. The unfertilized control recorded the lowest values for all parameters. The study indicates that integration of reduced prilled urea with nano-urea sprays can enhance productivity and nitrogen use efficiency of sweet corn under western Uttar Pradesh conditions.