Effects of Temperature and Exposure Period to Heat on Cogongrass (Imperata Cylindrica) Viability

Cogongrass, a rhizomatous perennial, is among the world's most troublesome weeds. Research was conducted at the Southern Weed Science Research Unit, Stoneville, MS, to determine cogongrass rhizome mortality with increasing temperature and duration of exposure to heat and to determine if 2,3,5 triphenyl tetrazolium chloride (TTC) 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 greater than or equal to 25, 5, 2.5, 2.5, 2.5, 2, 2 and 1 min, respectively. The duration of heat required for cogongrass mortality decreases as temperature increased. The standard greenhouse bioassay was more effective than tetrazolium chloride in predicting viability of cogongrass rhizomes following heat treatments. Nomenclature: Cogongrass, Imperata cylindrica (L.) Beauv. IMPCY