柑桔采后2,4-D处理的残留量研究

RESEARCH OF RESIDUES OF 2,4-D ON CITRUS FRUIT FOLLOWING POST-HARVEST DIP

采用^(14)C 同位素标记法,对锦橙(C.sinensin Osbeck)和红桔(C.reticula Blanco)采后2,4-D 处理的残留量进行了研究。结果表明,果蒂的残留量最高,黄皮层、白皮层和果肉依次递减。250ppm 处理锦橙和350ppm 处理红桔后5天,果肉残留量分别为2.5和3.2ppm,均超过 FAO 和 WHO 的规定;贮藏115天后分别为1.1和1.9ppm,低于规定残留量。锦橙可继续使用2,4-D处理,但浓度应控制在250ppm 以下,贮藏期应在60天以上才能食用。红桔贮藏期短,残留量较高,不宜用2,4-D 处理。

The residues of 2,4-D on orange(Citrus sinensis Osbeck)and tangerine(C.reticula Blanco)fruits treated with 150,250 and 350 ppm ^(14)C labelled 2,4-D were observed.In the treatment of sweet orange with 2,4-D at 250 ppm and the treatment of tangerine at 350 ppm,2.5 and 3.2 ppm were found in the pulp of the fruit 5 days after the treatment,which exceed the allowable level according to the standards of FAO and WHO,and 1.1 and 1.3 ppm remained 115 days after the treatment.Therefore,application of 2,4-D to sweet or- ange at concentrations below 250 ppm may be practiced on the condition that the fruit is consumed more than 60 days after the treatment.Application of 2,4-D to tangerine will be undesirable since its storage period is relatively short.