Publication Type: | Journal Article |
Year of Publication: | 2009 |
Authors: | Burke, IC, Yenish, JP, Pittmann, D, Gallagher, RS |
Journal: | Weed Technology |
Volume: | 23 |
Issue: | 4 |
Date Published: | 2009 |
ISBN Number: | 0890037X |
Keywords: | Lactuca |
Abstract: | Dose-response experiments were conducted on a biotype of prickly lettuce collected from Whitman County, WA, to determine the level of resistance to 2,4-D. Initially, progeny of prickly lettuce that survived two applications of glyphosate and 2,4-D in mixture were collected to determine if antagonism of the 2,4-D or glyphosate was occurring. Prickly lettuce survival was determined to not be due to antagonism of 2,4-D or glyphosate when the two herbicides were applied in mixture. The doses required to reduce growth 50% (GR₅₀) for resistant and susceptible field-collected prickly lettuce were 150 and 6 g ae/ha 2,4-D, respectively, indicating the resistant biotype was 25 times more resistant to 2,4-D than the susceptible biotype. The resistant biotype expressed injury but produced regrowth following application. A dose of 2,4-D at 220 g/ha was required to reduce regrowth frequency 50% (FR₅₀) for resistant field-collected prickly lettuce. Regrowth was also observed with the susceptible biotype, although the FR₅₀ was much lower (10 g/ha), resulting in an R/S ratio of 22 based on the respective FR₅₀ values. A rate of 4,300 g/ha 2,4-D (10 times the maximum labeled rate in wheat) was required to reduce the regrowth frequency in the resistant biotype to zero. |
URL: | http://www.jstor.org/stable/40587136 |
Short Title: | Weed Technology |
Resistance of a Prickly Lettuce (Lactuca serriola) Biotype to 2,4-D
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