Biochemical alterations in white yam (Dioscorea rotundata Poir.) under triazole fungicides: Impacts on tuber quality

An investigation was conducted to find out the effects of two triazole fungicides (triadimefon (TDM) and hexaconazole (HEX) - 15 and 10 mg/l per plant, respectively) on the biochemical constituents and tuber quality of white yam (Dioscorea rotundata Poir.). The exposure of white yam plants to the fungicides showd increased chlorophyll, carotenoids, xanthophylls, and anthocyanin contents and altered the membrane integrity in terms of electrolytic leakage and lipid peroxidation. The triazole treatments enhanced the accumulation of proline and total phenols in tubers. The visible symptoms of fungicides appeared as thickening and darkening of leaves. Both the triazoles increased the antioxidants (ascorbic acid, reduced glutathione, and tocopherol) contents. The data suggests that, apart from their fungicidal properties, the application of triazole fungicides may be a useful tool to increase the tuber quality in yam plants.