Irradiation as a phytosanitary treatment for controlling, Bactrocera zonata (Saunders) and its impact on different quality attributes of pomegranate fruits

Abstract

The study was conducted in order to assess the impact of gamma radiation on the different development stages of peach fruit fly, Bactrocera zonata, and to evaluate the influence of irradiation treatment on the physical, chemical, sensorial and microbiological qualities of pomegranate fruits. Pomegranate fruits were artificially infected with eggs and the 1st, 2nd and 3rd instar larvae of B. zonata and treated with different irradiation doses in the range of 50–400 Gy. The results indicated that no emerging adults were seen when eggs had been exposed to 100 Gy. The 3rd instar larva appeared to be the most tolerant stage to radiation treatment than the 2nd instar larva. Radiation treatment with 350 Gy resulted in 100% mortality in the 3rd instar larva. When adult emergence was used as criterion for measuring the effective irradiation dose, 150 Gy was required for disinfestation of the 3rd instar larva of B. zonata. Irradiation treatment of pupae either 3-or 7- days olds with 300 Gy prevented adult emergence. The irradiation dose level of 150 Gy used for the large – scale confirmatory tests was applied to 17,000 3rd instar larvae of B. zonata in pomegranate fruits resulting in non F1 adults’ production with confidence level of 81.7%. It could be conclude that the irradiation dose of 150 Gy prevented adult emergence from infested pomegranate fruits without causing significant (p ≤ 0.05) effect on the quality characteristics of the pomegranate fruits.