Yellow foxtail, Setaria glauca
Life Cycle
AnnualPropagation
Reproducing only by seed.Stems
Stem are normally round, but occasionally distinctly flattened.Leaves
Yellow foxtail is characterized by having a few, prominent, silky, kinky hairs (a) 3 - 10 mm long on the upper surface of the leaf blade just near the stem; ligule (b) a fringe of hair; no auricles; leaf sheaths split, their margins (c) smooth, green or slightly membranous and transparent.Flowers and Fruit
Inflorescence a spike (C) 2 - 10 cm long, covered with numerous, yellow to orange bristles (d) with forward-pointing barbs. Spikelets (“seeds” or “grains”) slightly larger than Green foxtail, more prominently cross-ridged, and yellowish or straw-coloured. Flowers from July to August.Roots and Underground Structures
Fibrous root system.Habitat
Yellow foxtail occurs throughout the agricultural regions of Ontario, having essentially the same distribution as Green foxtail but often being less abundant.Competitiveness
Corn yield loss (%)*:1 % at 1 plant/m2
5 % at 5 plant/m2
Soybean yield loss (%)*:
1 % at 1 plant/m2
5 % at 5 plant/m2
*assumes that the weed has emerged with the crop and has been left uncontrolled all season.
Distinguishing Features
It is distinguished from the other foxtails and, indeed, from all other grasses in Ontario by the prominent silky, kinky hairs on the upper surfaces of the leaf blades just near the stem.Toxicity
Yellow foxtail is not known to be toxic.Human Health Issues
Yellow foxtail is not a known allergen.Forage Quality
No information exists at this time.Species Benefits
No information available at this time.Often Mistaken For
Barnyard grass (ECHCG), Large crabgrass (DIGSA), Proso millet (PANMI), Witch grass (PANCA)Power Ranking Corn
Power ranking↑ 1
Power Ranking Soybeans
Power ranking↑ 4
Biological Control
Currently none available for this weed. Currently none available for this weed. For the latest research on biological weed control: Click hereBiopesticide Control
Currently none available for this weed.Herbicide Resistance
Triazine resistant (WSSA group 5) populations exist in York Region (ON).For more information on weed resistance:
Click here
Media Items
Figure 1: Yellow foxtail: A. Plant. B. Leaf-base. C. Spike. Top
Figure 2: Ligule: hairy. Top
Figure 3: Leaf blade: Base of leaf blade covered with a number of straggly hairs that are roughly 1-2 cm in length. Top
Figure 4: Leaf sheath: Hairless margins and very flat when compared to the round sheaths of green and giant foxtail. Top
Figure 5: Seed head. Top

