Abstract:

The Common-toxicity of the mixtures in plant extracts Hibiscu trionum L, Cynanchi auriculati and Rubia cordifolia L on Plutella xylostella was studied. The result showed that the mixtures of Cynanchi auriculati and Hibiscus trionum L in mix-proportion of 2:1 had remarkable synergistic effects, and common-toxicity cofficient(CTC) was 160.87. And the CTC of the experiment was 107.64, When Rubia Cordifolia mixed with Cynanchi auriculati in mix-proportion of 1: 3. However,The results also indicated that Rubia Cordifolia mixed with Cynanchi auriculati had no synergistic effect.