Effect of Density, Cultivars and Sowing Date on Onion Sets Production

Main aim of this experiment is production of the set onion from late winter to early spring in the Khuzestan (the Western Southern province) of Iran. The effects of sowing date of seed was studied at the present work has been chosen at three levels which are January, 21, February, 21 and March, 21 2005, at density (2, 4, 6 and 8 g m-2) and cultivars were used are Primavera, Taxes Yellow Grano, Ramhormozy and Behbahany on emerging date seeds and onion set production. Results have shown that onion set can be produced at late winter in Khuzestan province. Sowing date had affected on set size. The best date of set production for bulbs was late February. The biggest and smallest of set onion, respectively acquire in low and high density. The best density of set production for bulbs was 6-8 g m-2 and for green onion production 2-4 g m-2. Cultivars reaction to produce set was various. Reaction of Primavera' to environmental changes were faster than others cultivars and this promote the individual ‘Primavera' cultivar faster enter in to the rest phase.