Optimizing sowing date for short- and long-day onion

Abstract

ABSTRACT Bulb development of onion (Allium cepa L) varieties exhibit different reactions to sowing date, day length, and temperature. Short- and long-day onions exhibit different reactions to day length and temperature at sowing date as it affects bulb development. Seed of short-day ‘Mirela’ and ‘Es13022ʹ, and long-day ‘White Gorgan’ was sown on 2 March and 29 October 2017 to investigate vegetative development. October sown onion had greater vegetative yield. ‘Mirela’ and ‘Es13022ʹ had wider bulbs than ‘White Gorgon’ for both sowing dates. Short-day onion accessions ‘Mirela’ and ‘Es13022ʹ reached the greatest vegetative development earlier than long-day ‘White Gorgan.’ Short–day varieties sown in October could be suitable for off-season production.