EFFECT OF IRRADIATION AND 1-METHYLCYCLOPROPENE ON SHELF LIFE AND POST- HARVEST QUALITY OF ONION BULBS UNDER AMBIENT STORAGE CONDITION

Abstract

The experiment was carried out at the Postharvest Laboratory of the Department of Horticulture, Sher-e-Bangla Agricultural University in Dhaka to observe the effects of irradiation and 1-MCP on shelf life and postharvest quality of onion bulbs during the period from March 2022 to June 2022. The onion variety used in this experiment was Indian Mori kata piaz. The experiment comprised four levels of gamma irradiation viz., I 0 = 0.00Gy, I 1 = 10Gy, I 2 = 60Gy, I 3 = 120Gy and four levels of 1-methylcyclopropene (1-MCP) viz., M 0 = 0.00 ppm, M 1 = 150 ppm, M 2 = 300 ppm, M 3 = 450 ppm were used in this experiment. The experiment was laid out in a completely randomized design (CRD) with three replications. Data revealed that Physiological weight loss and the rotting percentage were higher in the untreated (control) bulbs. In gamma radiation treatment, the minimum weight loss (17.01%), rooting percentage (7.9%) at 90 DAS. Maximum shelf life (110.83 days) of onion was found in I 3 treatment. In different 1-MCP treatment, the minimum weight loss (17.88%), minimum rotting percentage (12.61%), minimum total soluble solid (15.75 ºBrix) at 90 DAS. Maximum shelf life (103 days) of onion was found in M 3 treatment. The gamma irradiation treatment at 120 Gy in combination with 450 ppm 1-MCP preserved the quality of the onion bulbs for approximately 120 days under ambient condition. From the results, it may be concluded that treatment I 3

(120 Gy+ 450 ppm 1-MCP) could be used to prolong shelf life, reduce rotting percentage and quality retention of onion.