Background:Cultivation of red dragon fruit(Hylocereus polyrhizus)in Indonesian orchards is hampered by anthracnose and stem canker.A mixture of azoxystrobin 200 g/L+difenoconazole 125 g/L is recommended in supporting ...Background:Cultivation of red dragon fruit(Hylocereus polyrhizus)in Indonesian orchards is hampered by anthracnose and stem canker.A mixture of azoxystrobin 200 g/L+difenoconazole 125 g/L is recommended in supporting the obligated integrated pest management.For the consumer safety,dietary intake of the residues from fresh edible part should be assessed;therefore,information on correct dissipation pattern of the applied pesticide is required.Materials and Methods:Field residue trials in Indonesian highland(West Java)and coastal area(Special Region of Yogyakarta)were done at recommended dose was 0.151 kg ai/ha azoxystrobin and 0.094 kg ai/ha difenoconazole,three times at 10 days interval.Whole fruit samples were collected at 70%-100%ripeness at−1,0,1,3,7,10,and 14 days after last application,processed and determined its residue as soon as possible.Result and Discussion:Photoisomerization of azoxystrobin was observed at Day 0,especially in coastal area;however,it has been dissipated to below lowest validated level in the following day.At Day 0,3%-5%of the deposited azoxystrobin and difenoconazole penetrate into the flesh;however,most residues(95%-97%)were retained in peel,and dissipated in prolonged day.The dissipation pattern was non-linear.The dissipation data were better fit with bi-exponential double-first-order in parallel than single first-order kinetics model.The DT50 of both azoxystrobin and difenoconazole was 3 days.At harvest time,seventh day,only azoxystrobin residue was detected in flesh at 0.006 mg/kg;therefore,the long-term dietary risk was 0 per cent acceptable daily intake.Conclusion:Fresh red dragon fruit is safe to consume.展开更多
文摘Background:Cultivation of red dragon fruit(Hylocereus polyrhizus)in Indonesian orchards is hampered by anthracnose and stem canker.A mixture of azoxystrobin 200 g/L+difenoconazole 125 g/L is recommended in supporting the obligated integrated pest management.For the consumer safety,dietary intake of the residues from fresh edible part should be assessed;therefore,information on correct dissipation pattern of the applied pesticide is required.Materials and Methods:Field residue trials in Indonesian highland(West Java)and coastal area(Special Region of Yogyakarta)were done at recommended dose was 0.151 kg ai/ha azoxystrobin and 0.094 kg ai/ha difenoconazole,three times at 10 days interval.Whole fruit samples were collected at 70%-100%ripeness at−1,0,1,3,7,10,and 14 days after last application,processed and determined its residue as soon as possible.Result and Discussion:Photoisomerization of azoxystrobin was observed at Day 0,especially in coastal area;however,it has been dissipated to below lowest validated level in the following day.At Day 0,3%-5%of the deposited azoxystrobin and difenoconazole penetrate into the flesh;however,most residues(95%-97%)were retained in peel,and dissipated in prolonged day.The dissipation pattern was non-linear.The dissipation data were better fit with bi-exponential double-first-order in parallel than single first-order kinetics model.The DT50 of both azoxystrobin and difenoconazole was 3 days.At harvest time,seventh day,only azoxystrobin residue was detected in flesh at 0.006 mg/kg;therefore,the long-term dietary risk was 0 per cent acceptable daily intake.Conclusion:Fresh red dragon fruit is safe to consume.
