The onion crop is irrigated immediately after transplanting. Frequent and light irrigations at weekly interval results in good bulb development and increased yield. In kharif season, depending upon the rains, 8-10 irrigations are sufficient. Late kharif crop requires 12-15 irrigations while for rabi season crop 15-20 irrigations are given. At bulb formation, irrigation is necessary as moisture stress at this stage results in low yield, splitting and forced maturity. For kharif season crop, irrigation should be stopped 10 days before harvesting. In rabi season it should be stopped when tops mature and start falling. Last irrigation given 10-15 days before harvesting reduces storage losses.