|Koger iii, Clifford|
Submitted to: Weed Technology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 5/29/2006
Publication Date: 3/13/2007
Citation: Bryson, C.T., Koger III, C.H., Byrd, J.D. 2007. Effects of temperature and exposure period to heat on cogongrass (imperata cylindrical) viability. Weed Technology 21:141-144. Interpretive Summary: Cogongrass, a Federal Noxious Weed, is considered the World’s seventh worst weed. It continues to spread at an alarming rate in the southeastern United States. Few economical chemical and non-chemical control methods are known for cogongrass control. Research determined that cogongrass rhizomes could be killed with the amount and duration of heat produced by an asphalt plant furnace. Federal, state, and local departments of transportation and utility companies could effectively excavate and kill cogongrass plants with heat, then return the dead plants in soil fill along right-of-ways. Thus, the need for repeated herbicide applications to control cogongrass could be eliminated.
Technical Abstract: Cogongrass, a rhizomatous perennial, is among the world’s most troublesome weeds. In 2003 and 2004, research was conducted at the Southern Weed Science Research Unit facilities, Stoneville, MS to determine cogongrass rhizome mortality with increasing temperature and duration of exposure and to determine if tetrazolium chloride could be used to evaluate cogongrass rhizome mortality following heat treatment. Cogongrass rhizome mortality was 100% at 65, 79, 93, 107, 121, 149, 177, and 187 C at time periods > 25, 5, 2.5, 2.5, 2.5, 2, 2 and 1 min, respectively. The duration of heat required for cogongrass mortality was less as temperature was increased. Standard greenhouse bioassay was more effective than tetrazolium chloride in predicting viability of cogongrass rhizomes following heat treatments.