|MULLINIX, JR, B|
Submitted to: American Society of Agronomy Meetings
Publication Type: Abstract Only
Publication Acceptance Date: 1/1/2001
Publication Date: 6/1/2001
Citation: Webster, T.M., Hanna, W.W., Mullinix, Jr., B.G. 2001. Herbicide dose-response relations among several bermudagrass cultivars [abstract]. Proceedings of American Society of Agronomy. Paper No. 512.
Technical Abstract: Greenhouse studies were conducted to evaluate the sensitivity of twelve commercial and developmental bermudagrass hybrids from the Tifton breeding program to clethodim, glufosinate, and glyphosate. Each herbicide was applied at eight doses: 0, 0.625, 0.125, 0.25, 0.50, 1, 2, and 4-times the registered herbicide use-rate (0.14, 0.84, and 1.12 kg ai/ha for clethodim, glufosinate, and glyphosate, respectively). Data were regressed on herbicide dose using a log-logistic curve. This regression appeared to describe the data better for the slow acting herbicides, clethodim (r2 = 0.81 to 0.95) and glyphosate (r2 = 0.70 to 0.93), relative to the fast-acting glufosinate (r2 = 0.60 to 0.83). Relative to the standard use-rate, clethodim had the smallest I50 (herbicide dose that caused 50% inhibition) values of the three herbicides in 10 of the 12 cultivars tested (including TifEagle, TifSport, TifWay, and common bermudagrass). While there were differential herbicide tolerances among the tested bermudagrass cultivars, there did not appear to be any naturally occurring herbicide-resistance that could be commercially utilized.