Effect of Mother Bulb Size and Plant Density on Seed Quantity and Quality of Neishabour White Onion Variety

Optimum plant density and suitable size of mother bulb are important factors for onion seed production. To study the effect of bulb size and plant density on seed production of Neishabour white onion variety، this experiment was carried out in Agricultural Research Station of Neishabour in Iran. Factorial arrangement in randomized complete block design with three replications was used. Experimental factors induded three different bulb diameters (3-5، 5. 1-7، and 7. 1-9 centimeters) and three different plant spacing (10، 20 and 30 centimeters). Seed yield increased to 2011 kg ha-1 by increasing bulbs diameters (7. 1 to 9 centimeters) and decreasing the plant spacing (10 centimeters). Seed germination rate (%) and seed germination velocity increased with larger bulbs and wider plant spacing.