Jointed Goatgrass

Jointed goatgrass (Aegilops cylindrica L.) is a winter annual grass native to Asia and Europe. The weed was thought to be introduced into the U.S. as a contaminant in winter wheat seed. There have been multiple times and sites of introduction of JGG into North America. Some speculate that it was transported into Kansas around the late 19th century in contaminated 'Turkey' wheat seed brought from Russia by Mennonite settlers. Others reported it was brought into the Kansas in wheat made by the USDA, private seed firms, or individuals during the early 1900s.

The earliest herbarium record of JGG was collected in Centerville, Delaware in 1870. Other records show that it was found in Kansas and Washington in 1917, Oregon in 1926, and in Oklahoma in 1946.

Jointed goatgrass became a troublesome weed in winter wheat during the 1970s, probably because of the introduction of less competitive, semi-dwarf wheat, the extensive use of nitrogen fertilizers, short crop rotations, and reduced tillage.

Although jointed goatgrass is not native to North America it is now widely distributed in the United States In 1987 it was considered one of the ten most common weeds of cereals only in Colorado, New Mexico, and Oklahoma.  Jointed goatgrass is reported to be an important weed of small grains in Colorado, Kansas, New Mexico, Oklahoma, Oregon, Utah, Washington, and Wyoming.

The Problem.........
Jointed goatgrass is a devastating weed that infests 5 million acres of winter wheat in the United States and is spreading unchecked at a rate of 50,000 acres per year. Jointed goatgrass costs producers $145 million annually due to:

• Reduced yields - commonly 25 to 50% loss.
• Increased dockage
• Loss of export market
• Decreased land value
• Increased tillage required
• Reduced ability to meet conservation compliance
• Loss of certified seed market
• Rotations to less profitable crops

The Cause.........
Currently there is no way to selectively control jointed goatgrass in winter wheat.  Other factors that make jointed goatgrass difficult to control include:

• Jointed goatgrass emerges in the fall with the wheat crop and is similar in appearance to wheat, so the problem is often not identified.
• Jointed goatgrass spikelets are the same size as wheat making it difficult to clean from wheat seed and increasing the chance that the weed seed is planted with the crop the following year.
• The seed remains viable for five or more years and the weed proliferates in conservation tillage.
• Under dry conditions, jointed goatgrass is more competitive than wheat, further reducing yields.
• Wheat and jointed goatgrass are genetically related and can form hybrids, which is a concern for herbicide resistance management.