Phytoextraction Potential of Sunn Hemp, Sunflower, and Marigold for Carbaryl Contamination: Hydroponic Experiment

Abstract

The phytoextraction ability and responses of sunn hemp, sunflower, and marigold plants were investigated toward carbaryl insecticide at 10 mg L−1 and its degradative product (1-naphthol). All test plants exhibited significant carbaryl removal capability (65–93%) with different mechanisms. Marigold had the highest translocation factor, with carbaryl taken up, translocated and accumulated in the shoots, where it was biotransformed into 1-naphthol. Consequently, marigold had the least observable toxicity symptoms caused by carbaryl and the highest bioconcentration factor (1848), indicating its hyperaccumulating capability. Sunflower responded to carbaryl exposure differently, with the highest carbaryl accumulation (8.7 mg kg−1) in roots within 4 days of cultivation, leading to a partial toxicity effect. Sunn hemp exhibited severe toxicity, having the highest carbaryl accumulation (91.7 mg kg−1) that was biotransformed to 1-naphthol in the sunn hemp shoots. In addition, the different models were discussed on plant hormone formation in response to carbaryl exposure.