The effects of electron irradiation doses on storability of Iranian Onion cultivars

Onion (Allium cepa L.) is considered as an important vegetable that a considerable amount of the product is lost in the storage process. The loss prevention and reducing methods are related to the production stages and post harvest conditions. One of the effective methods after harvesting is irradiation of bulbs by ionizing radiations as gamma ray. This research was conducted for 2 years in Seed and Plant Improvement Institute for surveying of different ionizing electron doses on four cultivars composed Ghermeze Azar Shahr, Sefide Kashan, Dorcheh Isfahan and Sefide Qom. The research was performed in split plot design with three replications that cultivar and radiation doses were the main and sub factors, respectively. Irradiated bulbs were stored for four months in ambient conditions (10-15degC and 60-70% Rh) and the storage traits composed sprouting and rotting percentage, weight loss percentage, dry matter percentage and tissue firmness (kg/cm2) recorded in 40, 80 and 120 days intervals. The results showed that cultivars had significant difference in all traits. Sefid Qom and Ghermeze Azar Shahr cultivars had the least sprouting percentage and weight loss percentage in all periods. Dry matter percentage and tissue firmness in Sefid Qom was higher than other cultivars. The irradiation caused significant improvement in traits specially 120 days after storage. The reciprocal effects of experimental factors were not significant in traits exceptly in sprouting and rotting percentage after 80 days storing and weight loss after 120 days storing.