1 April 2011 Herbicide Effect on Napiergrass (Pennisetum purpureum) Control
George S Cutts, Theodore M Webster, Timothy L Grey, William K Vencill, R. Dewey Lee, R. Scott Tubbs, William F Anderson
Author Affiliations +

Field and greenhouse experiments were conducted to determine the effect of herbicides on napiergrass growth and control. In greenhouse experiments, hexazinone, glyphosate, and imazapic were applied POST, and carbon dioxide (CO2) assimilation was measured with the use of an open-flow gas-exchange system up to 22 d after treatment (DAT). Carbon dioxide assimilation was reduced to zero, indicating plant death, for hexazinone- and glyphosate-treated napiergrass by 2 and 12 DAT, respectively. Imazapic-treated napiergrass CO2 assimilation declined to a constant rate by 22 DAT, but never reached zero. Field studies at Chula and Ty Ty, Georgia, evaluated herbicides for napiergrass control. Herbicide treatments included autumn-only applications, autumn followed by spring applications, and spring-only applications. All autumn-applied treatments exhibited regrowth in the spring. Plants were not affected by cold winter temperatures. A spade tillage treatment was implemented in January 2010, but was not effective in controlling napiergrass. Spring treatments included split applications of autumn treatments and spring-only treatments of glyphosate, glyphosate plus sethoxydim, and imazapyr. Sequential autumn and spring treatments containing glyphosate at both locations failed to eradicate napiergrass. Imazapyr applied spring achieved 94% plant injury by 34 DAT, and indicated potential napiergrass control. Greenhouse results indicated multiple modes of action could be effective in reducing napiergrass growth, but were inconsistent with field results. Further field studies are needed to derive conclusive methods of napiergrass control.

Nomenclature: Glyphosate; hexazinone; imazapic; imazapyr; sethoxydim; napiergrass, Pennisetum purpureum Schum

Weed Science Society of America
George S Cutts, Theodore M Webster, Timothy L Grey, William K Vencill, R. Dewey Lee, R. Scott Tubbs, and William F Anderson "Herbicide Effect on Napiergrass (Pennisetum purpureum) Control," Weed Science 59(2), 255-262, (1 April 2011). https://doi.org/10.1614/WS-D-10-00130.1
Received: 22 September 2010; Accepted: 1 December 2010; Published: 1 April 2011
carbon assimilation
cellulosic biofuel
growth reduction
invasive species
Get copyright permission
Back to Top