Author
VENCILL, W - UNIVERSITY OF GEORGIA | |
GREY, T - UNIVERSITY OF GEORGIA | |
CULPEPPER, A - UNIVERSITY OF GEORGIA | |
SHILLING, D - UNIVERSITY OF GEORGIA | |
Webster, Theodore |
Submitted to: National Cotton Council Beltwide Cotton Conference
Publication Type: Proceedings Publication Acceptance Date: 2/15/2006 Publication Date: 5/1/2006 Citation: Vencill, W.K., Grey, T.L., Culpepper, A.S., Shilling, D., Webster, T.M. 2006. Physiology of glyphosate-resistant Palmer amaranth (Amaranthus palmeri). In: Proceedings of the 2006 Beltwide Cotton Conference, January 3-6, 2006, San Antonio, Texas. p. 2254-2258. Interpretive Summary: Technical Abstract: Populations of Palmer amaranth (Amaranthus palmeri) that have increased tolerance to glyphosate have been detected in Georgia. These populations are not controlled by glyphosate rates of four to ten times of that required to control glyphosate-susceptible biotypes. Laboratory studies were initiated to examine the mechanism of increased glyphosate tolerance. Absorption, translocation, and metabolism studies were conducted. Preliminary studies indicate no differences in absorption, but some differences in translocation between glyphosate-susceptible and glyphosate-resistant biotypes. The two biotypes do differ in the level of shikimate present after exposure to glyphosate. The glyphosate-resistant population does not have a shikimate buildup indicating an insensitive EPSP target site or other mechanism preventing glyphosate from getting to the target site. |