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International Journal of Agronomy
Volume 2010 (2010), Article ID 515807, 5 pages
http://dx.doi.org/10.1155/2010/515807
Research Article

Responses of Three Bromegrass (Bromus) Species to Defoliation under Different Growth Conditions

1Department of Plant Sciences, University of Saskatchewan, 51 Campus Drive, Saskatoon, SK, Canada S7N 5A8
2Semiarid Prairie Agricultural Research Centre, Agriculture and Agri-Food Canada, Swift Current, SK, Canada S9H 3X2

Received 30 June 2010; Accepted 24 August 2010

Academic Editor: Rodomiro Ortiz

Copyright © 2010 B. Biligetu and Bruce Coulman. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Bromegrass species are important forage crops in temperate regions of world. This study compared responses of three bromegrass species to defoliation in the greenhouse and field to determine if the former could predict responses in the latter. Experiments were conducted in 2006 and 2007 in Saskatoon ( N, W), Canada on meadow bromegrass (Bromus riparius Rehm.), smooth bromegrass (Bromus inermis Leyss.), and hybrid bromegrass (B. riparius X B. inermis) following defoliation to 5 cm stubble height. When defoliated at the vegetative stage, above-ground biomass was similar among the three species in the field, but meadow bromegrass produced greater above-ground biomass than smooth bromegrass in the greenhouse. When defoliated at the stem elongation stage, meadow bromegrass produced greater above-ground biomass than smooth bromegrass in both environments. In the field, for all defoliation treatments, tiller number was greatest in meadow bromegrass, intermediate in hybrid bromegrass, and least in smooth bromegrass. In the greenhouse, however, the three species did not differ in tiller number. Similar results were found for below-ground biomass. Thus, testing the effect of defoliation in the greenhouse environment did not accurately predict the effect in the field environment.