The Weed Science program at the University of Missouri administers extension, research and teaching programs to keep you informed of the latest findings in weed management.

Our online resources include a Missouri weed ID guide and a herbicide injury guide. Both of these guides are full of photos — to aid in the identification of a weed or the diagnosis of herbicide-caused crop injury, respectively. The herbicide injury guide is also available as a mobile app. In addition, we offer numerous publications, newsletter articles, videos and PowerPoint presentations on various aspects of weed control.

Fun facts

• Each acre of U.S. cropland contains 50 to 300 million buried weed seeds. Five to 10 percent of them germinate and emerge each year.
• Common ragweed plants typically release a billion pollen grains per plant from August through October, triggering allergic reactions for nearly 36 million Americans annually.
• Herbicides make it possible for American growers to use no-till production on 52 million acres, preventing 304 billion pounds of soil erosion annually.
• Ancient Egyptians wrapped their dead in the leaves of the giant reed (Arundo donax), now one of the worst riparian weeds in the U.S.
• An average waterhemp plant typically produces around 300,000 seeds that are the size of a pin head.
• Scientists have discovered that earthworms contribute to the spread of giant ragweed by systematically collecting and burying its seeds in their burrows.
• After a walk, Swiss engineer George de Mestral observed burs from common burdock (Arctium minus) stuck to his wool pants and his dog’s fur. A few years later he patented Velcro, an invention inspired by the weed.