[Objective] Prevention and control technology of stem-nematode on sweet potato was explored to provide reference for production of sweet potato. [Method] The control effects of five kinds of pesticides against stem-nematode on sweet potato were studied in serious disease field in Yantai. [Result] The D. destructors average population in the soil negatively correlates with yield increase,while it positively correlates with morbidity and disease index of sweet potato. These five pesticides like 30% phoxim mic...