Effects of methyl bromide and storage time on postharvest behavior of three different cultivars of pitaya fruit

New clones of pitaya (also known as dragon fruit) (Hylocereus undatus) crossed with other Hylocereus spp. have become a host to the fruit fly Bactrocers spp. in Australia's Northern Territories and north Queensland, thus transport of these fruits to the rest of the country will require a disinfestation treatment with methyl bromide. This is the first research investigating the potential of methyl bromide for disinfestation and postharvest behavior of these new fruit crops. Main-season fruit from the three cultivars ('Golden', 'Venus', and 'Sweety') were subjected to 32 g/m(3) of methyl bromide at 21 degrees C for 2 h and stored for a week at ambient temperature. At different times during the storage, fruit were examined for quality. Assessments included fruit color, flesh firmness, skin browning, brown brackets, dry head, and the presence of rot, at 2-3 day intervals. In general, the quality of the methyl bromide-treated fruit was not significantly different from the control fruits after storage for up to 3 days for 'Golden' and 'Venus', and 10 days in 'Sweety'. After that the flesh firmness declined, whereas brown brackets, skin color, and dry head increased. These defects were observed more in 'Golden' pitaya fruit than Venus and 'Sweety'. The shelf life of 'Golden' and 'Venus' fruit after methyl bromide treatment are quite similar to each other, while the 'Sweety' fruit has a longer shelf life than the other cultivars. Our results provide evidence that these clones have responded well to methyl bromide for fruit fly disinfestations and that the fruit quality of these clones during and after storage did not suffer as a consequence.