By STACY CAMPBELL
Cottonwood Extension District
Shattercane (Sorghum bicolor), sometimes called wild cane or black amber, is the same species as our domesticated sorghums. Some authorities give it the subspecies name drummondii to distinguish it from our cultivated varieties, though the taxonomy of this genus is often debated. What is certain, though, is that shattercane easily cross-pollinates with cultivated sorghums via insects and wind-dispersed pollen and also cross-pollinates with its weedy relative johnsongrass (Sorghum halapense).
Ecology - A native of Africa, this species is now widespread in areas of the world where domesticated grain or forage sorghums are grown. It is possible that sorghum arrived in the U.S. as early as the 1600s, but reliable records indicate that several documented introductions occurred in the early 1800s. Shattercane can be utilized by livestock as a forage, but it can accumulate toxic nitrates and prussic acid under certain conditions. Undigested seeds can be spread in manure applied to fields. Shattercane seeds can also be buoyant, allowing for dispersal in moving water. Birds and small mammals utilize its seeds. Shattercane is a host species for disease and insect pests of sorghum and corn. Yield losses from shattercane interference can be as high as 70% in corn and greater than 95% in soybeans.
Identification- shattercane is a warm-season plant growing up to 12 feet tall. The plant is quite variable in growth habits and tolerant of both heat and drought. The stems are unbranched, but the plant tillers at the base to form clumps. The leaves are generally smooth and display a prominent midrib. They can be up to 20 inches long and 2 inches wide. It has a short membranous ligule with a fringe of hairs at the top. The inflorescence is typically a loose panicle with several pendulous (drooping) racemes (branches). Seeds are dark brown and typically covered with deep purple to black chaff. The panicles, which can number from one to six per plant, produce between 500 and 1500 seeds each. A special layer of abscission cells at the base of the seeds allows them to easily dislodge (shatter) at maturity, giving the plant its common name. Management -to see the detailed herbicide management practices for shattercane control in soybean, sunflower, corn, grain and forage sorghum. Go to https://eupdate.agronomy.ksu.edu and see the Oct. 10th issue of the K-State Agronomy eUpdate.
To prevent the spread of shattercane seeds by harvesting infested fields last (where possible), thoroughly cleaning harvest equipment before moving to a new field, and controlling shattercane in ditches and roadways. These cultural control methods are good integrated weed management practices regardless of which crop is being grown.
Information provided by Sarah Lancaster and Patrick Geier, K-State Research & Extension Weed Management Specialist.
Stacy Campbell is a Crop Production Extension agent in the Cottonwood District (which includes Barton and Ellis counties) for K-State Research and Extension. You can contact him by e-mail at [email protected] or by calling 785-628-9430.