Effects of low levels of herbicides on prairie species of the Willamette Valley, Oregon. (16th September 2013)

• Record Type: Journal Article
• Authors: Olszyk, David; Blakeley‐Smith, Matthew; Pfleeger, Thomas; Lee, E. Henry; Plocher, Milton
• Is Part Of: Environmental toxicology and chemistry. Volume 32:Number 11(2013:Nov.)
• Page Start: 2542
• Page End: 2551
• Publication Date: 2013-09-16
• Subjects: Pollution -- Environmental aspects -- Periodicals; Environmental chemistry -- Periodicals; 615.902
• DOI: 10.1002/etc.2331
• Languages: English
• ISSNs: 0730-7268

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <sec id="etc2331-sec-0001" sec-type="section"> <p>The relative sensitivity of 17 noncrop plant species from Oregon's Willamette Valley was determined in response to glyphosate, tribenuron methyl (tribenuron), and fluazifop‐<italic>p</italic>‐butyl (fluazifop) herbicides. For glyphosate, <italic>Elymus trachycaulus</italic>, <italic>Festuca arundinacea</italic>, <italic>Madia elegans</italic>, <italic>Potentilla gracilis</italic>, and <italic>Ranunculus occidentalis</italic> were the most sensitive species, based on a concentration calculated to reduce shoot dry weight by 25% (IC25 values) of 0.02 to 0.04 × a field application rate of 1112 g active ingredient (a.i.) per hectare. <italic>Clarkia amoena</italic> and <italic>Lupinus albicaulis</italic> were the most tolerant to glyphosate, with IC25 values near the field application rate. <italic>Clarkia amoena</italic>, <italic>Prunella vulgaris</italic>, and <italic>R. occidentalis</italic> were the most sensitive to tribenuron, with IC25 values of 0.001 to 0.004 × a field application rate of 8.7 g a.i. ha<sup>−1</sup> for shoot dry weight. Five grass species were tolerant to tribenuron with no significant IC25 values. For fluazifop, 2 native grasses, <italic>E. trachycaulus</italic> and <italic>Danthonia californica</italic>, were the most sensitive species, with IC25 values of 0.007 and 0.010 × a field application rate of 210 g a.i. ha<sup>−1</sup>, respectively, for shoot dry weight, while a native grass, <italic>Festuca roemeri</italic>, and nearly all forbs showed little or no response. These results also indicated that the 3 introduced species used in the present study may be controlled with 1 of the tested herbicides: glyphosate (<italic>F. arundinacea</italic>), tribenuron (<italic>Leucanthemum vulgare</italic>), and fluazifop (<italic>Cynosurus echinatus</italic>). <italic>Environ Toxicol Chem</italic> 2013;32:2542–2551. © 2013 SETAC</p> </sec> </abstract>