The biology of Canadian weeds. 127. Panicum capillare L.

Panicum capillare L., witch grass, is an annual grass native to North America that infests field crops, small grains, grasslands, and a variety of other habitats. High seed production, a persistent seed bank, a tumble-weed seed-dispersing mechanism, and the ability to tolerate some herbicides contribute to the success of P. capillare in these habitats. Despite the widespread presence of P. capillare in crops, its actual impact on crop yield is not well documented. It is an additional host for several insect pests (e.g., cereal aphids) and diseases attacking crop species.