The post harvest treatments such as gamma-irradiation are known to reduce sprouting in onion. An, experiment was taken up to study the effect of gamma irradiation in dark red, light red, white and yellow colour onion varieties. The well-cured bulbs of 17 onion varieties were treated with 60 Gy dose of gamma rays and stored at ambient temperature from May to September. The observations on different types of losses were recorded at 15 day interval. The result revealed that gamma irradiation effectively checked sprouting in all onion varieties irrespective of their colour. There was no sprouting in irradiated bulbs of all varieties, while it was 0.0 to 34.3 percent in un-irradiated onions. There was no significant effect on physiological loss of weight, rotting and black mould infection. The total storage losses in irradiated onion were significantly less than unirradiated onion. The total losses in light red and yellow colour varieties were lower than dark red and white varieties.
Onion varieties, gamma irradiation, storage losses
