Submitted to: Invasive Plant Science and Management
Publication Type: Peer reviewed journal
Publication Acceptance Date: 3/6/2010
Publication Date: 7/1/2010
Citation: Bryson, C.T., Krutz, L.J., Ervin, G., Reddy, K.N., Byrd, J.D. 2010. Ecotype variability and edaphic characteristics for cogongrass (Imperata cylindrica) populations in Mississippi. Journal of Invasive Plant Science and Management. 3:199-207. Interpretive Summary: Cogongrass is a highly invasive noxious weed. It continues to spread at an alarming rate in the U.S. Cogongrass has been reported from a wide array of habitats; however, information exists for soil characterization from cogongrass populations. This research determined that soil parameters were highly variable among cogongrass populations, even within physiographic regions or land use areas within Mississippi. This diversity encompassed most of the soil physiochemical diversity reported for Mississippi. Research also determined that soil texture, soil pH, organic matter, and nutrients for cogongrass populations were more diverse than for optimum soil parameters for many native plants and agricultural crops. Cogongrass’ ability to establish, grow, and reproduce on this wide array of soils provides an advantage over other plant species.
Technical Abstract: Cogongrass (Imperata cylindrica) is a highly invasive perennial grass in the southeastern United States and is found on all continents except Antartica. It has been reported from a wide array of habitats; however, soils from cogongrass populations have never been characterized. Live cogongrass plants, herbarium specimens, and soil samples were collected from 53 cogongrass populations from each of the 10 physiographic regions and land use areas in Mississippi. Cogongrass was identified in soils varying widely in texture (ranging from 28 to 86% sand, 3 to 48% silt, and 6 to 43% clay), organic matter content (ranging from 0.9 to 5.0%), pH (ranging from 4.4 to 8.0), and nutrient status: 6 to 190 kg ha-1 of phosphorus (P), 46 to 734 kg ha-1 of potassium (K), 150 to 7620 kg ha-1 of calcium (Ca), 26 to 1090 kg ha-1 of magnesium (Mg), 1 to 190 kg ha-1 of zinc (Zn), 145 to 800 kg ha-1 of estimated sulfur (S) based on organic matter, and 57 to 300 kg ha-1 of sodium (Na). These soil parameters were highly variable among cogongrass populations, even within physiographic regions or land use areas, and encompassed much of the soil physiochemical diversity within the state. Soil characteristics were significantly correlated with leaf length (Ca, K, Mg, P, Zn, and percent sand and silt), width (Ca, P, Mg, and percent sand and silt), and leaf length to width ratio (K and P) and inflorescence length (Na, P, and pH), width (S, organic matter, and pH), and inflorescence length to width ratio (S and organic matter). These data indicate that cogongrass is able to establish, emerge, grow, and reproduce on a wide array of soils in Mississippi.