Reproducing only by seed.
Up to 2 m high, smooth.
Leaf sheaths mostly smooth, except hairy along the margins; leaf blades 30 - 55 cm long, 3 - 17 mm wide, usually finely hairy throughout the entire upper surface (G, H) of all leaves and occasionally also on the undersurface (seen by rolling the leaf over a finger and viewing it against the light); ligule a dense band of hairs, about 1.0 mm long; no auricles.
Inflorescence dense, spike-like, erect or the larger ones usually somewhat curved or nodding, 4.5 - 17 cm long and 1.5 - 3 cm thick, surrounded by light yellowish-green awn-like bristles which give the inflorescence a bottle-brush appearance; spikelets 1.5 - 3 mm long; grains (â€œseedsâ€) light green and abundantly cross-wrinkled. Flowers from late July to October.
Fibrous root system.
Giant foxtail is native to China and was recently introduced from the USA where it is a very common weed; it is becoming abundant in fields and waste places in southern and eastern Ontario.
Corn yield loss (%)*: 2 % at 1 plant/m2 10 % at 5 plant/m2 Soybean yield loss (%)*: 3 % at 1 plant/m2 12 % at 5 plant/m2 *assumes that the weed has emerged with the crop and has been left uncontrolled all season.
It is distinguished from Green foxtail by its usually larger, nodding inflorescence, its distinctly cross-wrinkled grains and usually hairy upper surface of leaves, and from Yellow foxtail by its larger, greenish-yellow rather than orange-yellow inflorescence, and by the upper surfaces of its leaf blades being finely short-hairy throughout their length rather than bearing a few long, kinky hairs near the stem. The technical character that distinguishes Giant foxtail from Green foxtail is that its second or upper glume covers only about Â¾ of the fertile floret, whereas in Green foxtail it covers nearly the entire floret.
Giant foxtail is not known to be toxic.
Giant foxtail is not a known allergen.
No information exists at this time.
No information available at this time.
Green Foxtail (SETVI), Fall Panicum (PANDI)
Currently none available for this weed. For the latest research on biological weed control: http://res2.agr.ca/Lethbridge/weedbio/index_e.htm#toc
Currently none available for this weed.
Populations resistant to sulphonylurea and imidazolinone (WSSA group 2)herbicides exist in Lambton county (ON). For more information on weed resistance: http://www.plant.uoguelph.ca/resistant-weeds/
Giant foxtail: G. Yound plant showing finely hairy leaf surfaces. H. Leaf-base showing dense covering of very short hairs on upper surface of leaf-base, hairy ligule with longer hairs at margins of collar, and short hairs along edge of leaf sheath.
Leaf blade: Hairy upper leaf surface and hairless lower leaf surface.
Leaf sheath: Hairy margins.