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RECORD NUMBER: 15 OF 95

OLS Field Name OLS Field Data
Main Title Effects of single and multiple stressors on communities of wheat and wild oats /
Author Pfleeger, Thomas G.
CORP Author Oregon State Univ., Corvallis.;Corvallis Environmental Research Lab., OR.
Publisher U.S. Environmental Protection Agency,
Year Published 1998
Report Number EPA/600/R-98/074
Stock Number PB98-151269
Subjects Wild oat--Effect of stress on. ; Wheat--Effect of stress on.
Additional Subjects Wheat ; Wild oats ; Theses ; Risk assessments ; Ecology ; Ecosystem management ; Natural resources ; Watershed ; Environmental stressors ; Puccinia recondita ; Spring wheat ; Wheat leaf rust
Holdings
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NTIS  PB98-151269 Most EPA libraries have a fiche copy filed under the call number shown. Check with individual libraries about paper copy. NTIS 01/01/1988
Collation 122 leaves, bound : illustrations ; 29 cm
Abstract
Most plant toxicology tests developed in support of environmental laws use a single stress applied to an individual plant. While tests using individual species or stresses require fewer resources and are easier to interpret, they are under increasing criticism for being unrealistic and missing important ecological interactions. The objective of this research was to increase our understanding of how plants and plant communities respond to a variety of stressors. Model plant communities of spring wheat (Triticum aestivum) and wild oats (Avena fatua) were planted at three densities and five proportions in the field. Puccinia recondita, the causal agent of wheat leaf rust, was inoculated on half of the plots. Disease severity was estimated as percent of wheat flag leaves covered by rust lesions. Plants were harvested at maturity and measured. Seeding density rarely had a significant influence on rust severity, probably because tiller density differed little as a result of compensation due to increased tillering at low seeding densities. In contrast, increasing the proportion of wheat in mixtures with wild oats consistently increased wheat leaf rust severity. There was no evidence to suggest that wild oats acted as a barrier to inoculum movement. Wild oats' effect on wheat leaf rust was probably through its competitive reduction of wheat tiller density. Both wheat and wild oats seed weight decreased as the proportion of wild oats increased in mixtures.
Notes
"June 1998." Includes bibliographical references. Microfiche.