field of soybeans with pigweed
U of A CES Pasture Weed Control Database
The Pasture Weed Control Database contains the same information and pictures included in the Miscellaneous Publication MP-522. The weeds are arranged alphabetically by scientific name because common names vary. For example, in Arkansas, Eupatorium capillifolium, is variously called, Dogfennel, Cypress Weed, and Texas Cedar.

Knotroot Foxtail, Setaria geniculata

Setaria geniculata

Knotroot Foxtail is a warm-season, perennial grass that forms seed heads in July. It is the most common foxtail in Arkansas. Knotroot produces small, knotty rhizomes (see photo inset). One option is to apply 8 to 10 fl oz per acre of 4 lb/gal glyphosate as soon as the hay is off the field. Panoramic at 4 to 6 fl oz/A does a fair job of foxtail control if it is in the seedling stage. Add 0.25% nonionic surfactant. Control of large plants will be poor. Application timing will typically be from late May to early June. Panoramic (imazapic) will stunt bermudagrass. Damage varies, but the loss of one hay cutting is typical. Expect 30 to 45 days of bermudagrass suppression after application. Do not apply to drought-stressed bermudagrass. Do not apply during spring transition. Do not apply to newly sprigged or seeded bermudagrass.