Single and Joint Toxicity of Sulfamonomethoxine and Cadmium on Three Agricultural Crops

In order to evaluate ecological risk of agrochemicals in an agricultural environment, single and joint toxic effects of sulfamonomethoxine (SMM) and cadmium (Cd) on seed germination of wheat (Triticum aestivum L.), Chinese cabbage (Solanum lycopersicum), and radish (Raphanus sativus L.) were investigated. The results showed that the root and shoot elongation were significantly affected under the contamination condition (P < 0.05). In the single-factor experiments, the toxic effect of SMM on crops was much stronger than that of Cd. In the joint effects of SMM and Cd, the interactive effects of the two pollutants on root/shoot elongation of the three crops were complicated, while SMM and Cd had significantly (P < 0.05) synergic effects on root/shoot elongation of the three crops. At the low concentration of SMM, SMM and Cd had significantly (P < 0.05) synergic effects on root/shoot elongation of the three crops, but antagonistic effects were found when the concentration of SMM was high.