The field trials of the present experiment were conducted to study the response of nitrogen and phosphorus fertilization on the onion growth and yield during the Rabi season 2021-22 at the Vegetable Farm of College of Agriculture of Guru Kashi University at Bathinda. The plant material comprised onion (Allium cepa L.) variety “N-53” which has been recommended by PAU, Ludhiana for cultivation in the state during rabi season. The field experiments were laid out in split plot design. The treatments comprised three levels of nitrogen and three levels of phosphorus i.e.N = 100(N1), 150 (N2) and 200 (N3) kg/ha and P = 50 (P1), 75 (P2) and 100 (P3) kg/haof chemical fertilizers and its combination. Each treatment was replicated thrice.The observations were recorded for ten randomly selected plants and leaving two border rows from each plot. The data were recorded with respect to the plant height (cm) at 60, 90,120 and at last harvest, number of leaf length(cm) at 60, 90 and 120 days, bulb weight (gm) and bulb yield (t/ha).Nitrogen 200 kg/ha and phosphorous 100 kg/ha showed the maximum height of 33.70cm, 39.46cm, 54.48cm and 56.17 cm and leaf length 32.99cm, 50.50cm, 45.19cm and 47.cm at 60 DAP, 90 DAP, 120DAP and at the time of harvest respectively. The dose of 200 kg/ha N and 100 kg/ha P increased the bulb weight 89.60 gm at maturity and marketable bulb yield 22.32 t ha-1. The current study revealed that the highest bulb yield of onion cv. N-53 can be achieved with the incorporation of 200 kg nitrogen and 100 kg phosphorus per ha.
