HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Cohen, C. J. Articles by Frakes, R. V. Search for Related Content PubMed Articles by Cohen, C. J. Articles by Frakes, R. V. Agricola Articles by Cohen, C. J. Articles by Frakes, R. V.

Gas Exchange and Leaf Area Characteristics of Four Tall Fescue Selections Differing in Forage Yield¹

Gas exchange and leaf area characteristics of four tall fescue (Festuca arundinacea Schreb.) selections differing in forage yield were examined under greenhouse and laboratory conditions to determine if these characteristics might be related to yield differences. Carbon dioxide exchange rates (CER) and specific leaf weight of leaf blades of ten genotypes per selection were measured in December 1978 and April 1979. In April 1979, dark respiration and transpiration rates of leaf blades were also evaluated. Leaf elongation rate, leaf width, and leaf area expansion rate were assessed during three measurement periods.

In December 1978, the lowest-yielding selection, TFM 16, had 20% greater CER than the high-yield selections, TFM 26 and TFK 4, and 8% greater CER than TFK 12. Differences in CER were not statistically significant in April. No significant differences among selections for transpiration, dark respiration, or specific leaf weight were found.

High yielding TFM 26 had significantly greater leaf elongation and leaf area expansion rates in one measurement period (by 28 to 48% and 24 to 43%, respectively), but differences among selections were not significant in two other periods. Low-yielding TFM 16 had leaves that were more than 20% narrower than those of the other selections. Leaf width was a relatively more stable morphological character than leaf elongation or leaf area expansion rate.

Key Words: Festuca arundinacea Schreb. • CO₂ exchange rate • Dark respiration • Transpiration • Specific leaf weight • Leaf width • Leaf elongation rate • Leaf are expansion rate

² Form graduate research assistant and research assistant, present address ARCO Plant Cell Research Inst., 6560 Trinity Crt., Dublin, CA 94566; professor of Agronomy, Dep. of Crop Science, Oregon State Univ., Corvallis, OR. 97331; and former professor of Agronomy, presently associate dean of Research, Research Office, Oregon State Univ., Corvallis, OR. 97331.

Received for publication November 10, 1980.