Effect of plantinggeometry and nitrogen on yield, economics and nitrogen uptake of sweet corn (Zea mays)

A field experiment was conducted during rainy seasons of 2002 and 2003 at Central Research Station, OUAT, Bhubaneshwar to study the effect of planting geometry and nitrogen on sweet corn (Zea mays L.) cv 'Madhuri'. Twenty treatment combinations, comprising four spacings (45 cm x 30 cm, 45 cm x 20 cm, 60 cm x 30 cm and 60 cm x 20 cm) allotted to the main plots and five nitrogen levels (0, 20, 40, 60 and 80 kglha) to the sub- plots, were tested in split-plot design with three replications. The spacing of 60 cm x 20 cm significantly in- creased the number of prime cobs (54,108/ha), green-cob yield (9.21 t o ~ e d h a ) , nitrogen uptake (53.62 kglha), protein yield (174.35 kglha) and accrued highest net return (Rs 48,5711ha) and benefit : cost ratio (3.55), fol- lowed by 45 cm x 30 crn spacing. Application of 80 kg Nlha produced significantly highest number of prime cobs (62,328/ha), green-cob yield (9.80 tonneslha), length (17.5 cm) and girth (16.7 cm) of cobs, green-forage yield (17.35 tlha), total N uptake (91.2 kglha) and protein yield (280.8 kglha). Significantly highest net returns (Rs 61,5321ha) and benefit : cost ratio (3.76) were realized with 80 kg Nlha, followed by 60 and 40 kg Nlha.