Table 1.
Trade name | Manufacturer | Mode of action | Chemical family | Active ingredient (a.i.) |
---|---|---|---|---|
Arsenal™a | BASF Corporation, Research Triangle Park, NC, USA | ALS inhibitor | Imidazolinone | Imazapyr |
Beacon™ | Syngenta Crop. Protection Inc., Greensboro, NC, USA | ALS inhibitor | Sulfonylurea | Primisulfuron-methyl |
FirstRate™ | Dow AgroSciences LLC, Indianapolis, IN, USA | ALS inhibitor | Triazolopyrimidine | Cloransulam-methyl |
Oust™ | E.I. du Pont de Nemours and Company, Wilmington, DE, USA | ALS inhibitor | Sulfonylurea | Sulfometuron methyl |
Roundup original™ | Monsanto Company, St. Louis, MO, USA | EPSPS inhibitor | – | Glyphosate |
Trade name | % a.i. | A.th. treatment concentration (g ha−1 a.i.)b | B.n. treatment concentration (g ha−1 a.i.)b | |
---|---|---|---|---|
Arsenal™a | 53.1 | 0.395 | 1.429 | |
Beacon™ | 75.0 | 0.586 | 9.058 | |
FirstRate™ | 84.0 | 0.163 | 0.549 | |
Oust™ | 75.0 | 0.131 | 0.886 | |
Roundup original™ | 41.0 | 10.652 | 79.745 |
Abbreviations: ALS acetolactate synthase, EPSPS 5-enolpyruvylshikimate-3-phosphate synthase, A.th. Arabidopsis thaliana, B.n. Brassica napus. Treatment concentrations were determined to result in comparable reductions in growth (“Materials and methods”). In addition to active ingredients, the herbicides contain inert components indicated in Material Safety Data Sheets
aApplicators concentrate
bThe herbicide rates [% of the field application rate active ingredient (f.a.r. a.i.)] estimated to produce a 50% reduction in shoot dry weight based on nonlinear regression analysis of data from a range-finding dose response study. A probit model was used to identify the EC50 values for A.th., while the Weibull model, which was developed later for use in these herbicide studies, was used with B.n.. For B.n. and Roundup Original™ the herbicide concentration used was enough to cause approximately 60% reduction in shoot dry weight based on the Weibull model