Effect of agronomic measures on population dynamics of sweet potato stem nematode (Ditylenchus destructo) Identification of the pathogenic nematodes from potatoes in Dingxi of Gansu Province Cloning and Prokaryotic Expression of Dd-Gpx from Ditylenchus destructor Effects of low-dose nematicides on expression of three HSP70 mRNA in Ditylenchus destructor Susceptibility of acetylcholinesterase of different populations of Ditylenchus destructor to inhibitors Toxicity and bioactivity of several alternative nematocides against Ditylenchus destructor. Effects of intercropping patterns on growth characters and yield of Angelica sinensis under continuous mono-cropping planting