The effect of gamma irradiation on seed weevil, fruit flies and fruit quality of different mango cultivars.
Joubert P. H., Grové T.
Author Affiliation: Institute for Tropical and Subtropical Crops, Private Bag X11208, Nelspruit 1200, South Africa.
: 75-78
Abstract : The effect of gamma irradiation was evaluated on the ability of mango seed weevil, Sternochetus mangiferae, to emerge from the seeds, the survival of marula fruit fly, Ceratitis cosyra, and fruit quality of three commercial cultivars. Sensation fruits containing adult seed weevils, marula fruit fly eggs and 1st and 2nd instar larvae were irradiated at dosages ranging from 200 to 500 Gy. Uninfested Heidi, Tommy Atkins and Kent fruit were similarly irradiated, stored for 28 days at 11°C, ripened at ±25°C and evaluated for fruit quality. During a 14-week period following irradiation, adult weevils emerged from all the treatments and it was concluded that even the 500 Gy dose was insufficient for phytosanitary purposes. Marula fruit fly eggs did not survive any of the radiation treatments, while larvae were still alive after 7 days. Fruit quality of Tommy Atkins and Kent was not significantly affected by any of the treatments, while Heidi fruits suffered severe scalding. The selected dose range would be inappropriate for phytosanitary purposes when South African mangoes are exported.