Abstract: The allelopathic potential of invasive alien weed Sorghum halepense（L.） Pers. (Johnsongrass) to wheat, maize and cotton was investigated by the laboratory tests of seed germination and seedling growth. The results demonstrated that S. halepensecould inhibit the seed germination and seedling growth of the three crops. The allelopathic potential of S. halepense increased with its concentration, but decreased with time. At 0.1 g·ml^-1 of S. halepense, the seed germination rate of wheat was decreased from 404% on the 3rd day to zero on the 20th day, and the seedling growth of the three crops was inhibited on the 3rd or 10th day but not affected on the 20th day. The allelopathic potential of S. halepense could be one of the reasons of its successful invasion.

Key words: Distributed hydrological model, Forested watershed, Rainfall-runoff process, Scaling